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North American Vegetable Pests: The Pattern of Invasion

March 2002
American Entomologist 48(1)

DOI:10.1093/ae/48.1.20

Authors:

John Capinera

University of Florida

Origins of vegetable pests (n = 126) that successfully invaded the United States and Canada, expressed in percentage.

…

Temporal pattern of invasion of United States and Canada by vegetable pests (n = 87), expressed as number and percentage in each time period.

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Taxonomic distribution of invaders (n = 135) and indigenous vegetable pests (n = 197) expressed as percentage.

…

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Content uploaded by John Capinera

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20 AMERICAN ENTOMOLOGIST • Spring 2002

tive) and nonindigenous (invader, adventive, exotic) pests

of vegetable crops in the United States and Canada.

Analysis

To determine the origin and biological charac-

teristics of vegetable pests, I reviewed the original

scientific literature of over 330 pests known to feed

on vegetable crops (Capinera 2001 and references

therein), and compiled data on pest origin, period

of introduction, host range, portion of plant dam-

aged, and damage frequency. In most cases the lit-

erature contains reference to the likely source of these

pests (126 of 135 invaders). However, for some

cosmopolitan pests or poorly studied organisms

the source is unknown or uncertain. Similarly, the

period of detection in the United States and Canada

varies from precise to unknown, with knowledge of

the period of establishment (detection) limited to 87

of the 135 invading pests. Lack of data stems mostly

from the early period of settlement, but invasions

since 1900 are fairly well documented.

The host range of the vegetable pests is quite

well documented in the literature, although there is

a tendency for species that are better studied to

have longer lists of hosts. Also, during periods of

great abundance (outbreak), pests often use hosts

that they will not normally accept. Thus, outbreak

species probably have inflated host ranges. For the

purposes of this analysis, I have defined a narrow

host range to consist of consumption of vegetable

plants from a single botanical family. A moderate

host range consists of consumption of vegetable

plants from two to five families, and a wide host

range is defined as consumption of greater than

five families of vegetable crops.

Damage frequency is based on the literature for

each pest, as described elsewhere (Capinera 2001),

and considers damage to both home gardens and

commercial vegetable production. Damage fre-

quency is designated as rare when there are few

reports of serious injury in the literature. Damage

frequency is considered periodic when there is gen-

eral recognition that the organism is capable of

The successful

establishment

in North America of

invading pests is not a new phe-

nomenon. Since the earliest arrival

of European explorers and colonists,

pests of plants have accompanied move- ment

of people, food, and plant materials to the “New

World.” The long sea voyage during the initial

stages of colonization likely inhibited extensive

transport of many short-lived pests. Up until 1800,

only about 36 species of insects invaded the United

States (Simberloff 1986). However, by the late

1800s not only was the speed of transport greatly

increased, but transport of living plant material

(and associated pests) was commonplace.

Sailer (1978, 1983) analyzed the invasion of

the United States by arthropods. He reported that

initially the invaders (immigrants) consisted mostly

of Coleoptera, which arrived principally in ship

ballast. The dominance by beetles decreased as more

Lepidoptera and then Homoptera invaded, often

in association with living plant material. The rate

of invasion increased greatly after the 1860s as

international commerce expanded. Sailer also noted

that there was a slight reduction in the rate of inva-

sion commencing in the 1920s as the Plant Quar-

antine Act of 1912 was implemented.

Invasion by high-profile and damaging species

in recent years has increased the awareness and

concern by the scientific community, government,

and the general public over invading species (U.S.

Congress 1993, Simberloff et al. 1997, Sakai et al.

2001). The pattern of invasion is poorly docu-

mented, despite heightened concern, and many ques-

tions remain. Has the increase in international

commerce and tourism in recent years resulted in

higher rates of invasion and establishment of pests?

Are we at greater risk from certain types of pests, or

from certain sources? Are certain taxa of pests more

likely to invade and establish successfully, and are all

crops equally at risk? Here I address these questions

and present a comparative analysis of indigenous (na-

Increased concern over invasion by high-profile and damaging insects

requires the answers to questions about the origin of pests, period of

invasion, taxa, feeding behavior, damage frequency, and the

influence of crop characteristics on pest species richness.

John L. Capinera

AMERICAN ENTOMOLOGIST • Volume 48 Number 1 21

causing crop injury, but the pest does not cause

loss annually, and vegetable growers do not nor-

mally take preventative measures to guard against

injury. Pest damage is considered frequent when

the potential to cause injury exists annually in ei-

ther home gardens or on farms, and characterizes

pests for which vegetable producers annually plan

for suppressive or preventive actions. Pests are des-

ignated as capable of periodic or frequent damage

if this pattern is exhibited even in a limited geo-

graphic area, because most pests have limited geo-

graphic distribution.

Designation of the site of damage is based on

the scientific literature, and consists of blossom

(flower); fruit (seed-containing structure); foliage;

stem or vine; tuber (below-ground storage organ);

and root, bulb, or germinating seed (below-ground

root-related structures).

The 332 pests considered in this analysis are, in

nearly all cases, individual species. However, the

economic literature tends to group some pests into

complexes either because they are poorly known

or difficult to differentiate. Therefore, a few pests

(e.g., false wireworms, Coleoptera: Elateridae; white

grubs, Coleoptera: Scarabaeidae) are treated as in-

dividual pests although more than one species is

involved. Also, some literature is confusing because

pests originally thought to be a single species have

since been differentiated into species complexes (e.g.,

spinach and beet leafminers, Pegomya spp., Diptera:

Anthomyiidae; dingy cutworms, Feltia spp., Lepi-

doptera: Noctuidae). These issues are minor, how-

ever, and likely have little effect on the analysis.

The aforementioned data on pest characteris-

tics were analyzed by 2 × 2 contingency table analy-

sis using Fisher’s exact test (Zar 1984). In the case

of feeding behavior, I compared the number of spe-

cies with wide host range to the number of species

with narrow host range for both indigenous and

nonindigenous species. For the noctuid and pyralid

analysis, I also analyzed the number of species with

narrow and wide host ranges for each family. For

damage frequency, I compared the number of spe-

cies causing damage rarely or frequently for both

indigenous and nonindigenous species.

Regression analyses were conducted on area

planted to major commercial vegetable crops, to-

tal crop value, and unit value in relation to the

total number of pest species or number of major

pest species per crop. Major pest species were those

capable of “frequent” and “periodic” damage, as

described previously. Correlation analyses were

performed on crop acreage and crop value data,

and on crop acreage and crop unit value data. All

data were log-transformed prior to linear regres-

sion or correlation (Graphpad Software 1993).

Such transformation linearizes curvilinear rela-

tionships, and normalizes residuals and makes

them homocedastic. Although not always improv-

ing the fit of the model (Conner and McCoy 1979),

this is a common practice in analysis of species-area

relationships. The crops analyzed in this manner were

artichoke, asparagus, bean, broccoli, cabbage, cauli-

flower, carrot, celery, cucumber, lettuce, melons (pri-

marily cantaloupe and honeydew), onion, pea, pep-

per, potato, spinach, sweet corn, sweet potato, to-

mato, and watermelon. Data on crop acreage and

value are from Capinera (2001), and consist of

summed American and Canadian values.

Origins of Vegetable Pests

Of the 332 vegetable pests considered in this

analysis, 99% were successfully classified as either

indigenous (native) or nonindigenous (invaders),

and 59% appeared to be indigenous to the United

States or Canada (Appendix 1). Similarly, Pimentel

(1993) estimated that 63% of major American veg-

etable pests are indigenous, though this figure is

based on a subset of vegetable crops. It is evident

that our native fauna displays considerable plas-

ticity in acquiring new hosts. This trend has been

noted previously, and we can expect the number of

pests to increase with time, and especially with the

area planted to each particular crop (Strong 1974,

Strong et al. 1977, McCoy and Rey 1983, Capinera

et al. 1984a), as indigenous species adapt to im-

ported host plants, or crops are exposed to addi-

tional potential pests in new geographic areas.

However, species accrual on introduced crops oc-

curs most rapidly soon after plant introduction,

and species richness on crops does not increase

indefinitely, leveling off after fewer than 300 years

if there is not an increase in crop acreage (Strong

1974). Also, it is important to note that though

indigenous pests form a large assemblage, they do

not necessarily cause damage frequently (see dis-

cussion of pest damage below).

Europe is the principal origin of the nonindig-

enous vegetable pests found in North America.

About 54% are thought to have originated there,

or to have arrived in North America via that re-

gion (Fig. 1). This is not surprising because the

United States and Canada were colonized princi-

pally by Europeans, who introduced European

crops, and possibly allowed European pest “hitch-

hikers” to arrive. The introduction of crops, the

repeated waves of European immigration, the ex-

tensive trade between Europe and North America,

and the introduction of European ornamental

plants to North America all contributed to the pre-

Fig. 1. Origins of vegetable pests (

= 126) that successfully invaded the United

States and Canada, expressed in percentage.

Pest damage

is considered

frequent when

the potential

to cause injury

exists annually in

either home gardens

or on farms

22 AMERICAN ENTOMOLOGIST • Spring 2002

ponderance of European pests. Sailer (1978) also

reported that non-indigenous species came predomi-

nantly from the European region (western Palearc-

tic), although beneficial insects introduced for

biological suppression of pests also were included

in his calculations. Pimentel (1993) estimated that

37% of major American pests originated in Europe,

although this estimate is based on a large number of

crops, not just vegetables. Lindroth (1957) provided

a long list of fauna common to Europe and North

America. The invasion of large numbers of Euro-

pean pests is not limited to North America, as it also

has occurred in Australia, New Zealand, and South

Africa (Simmonds and Greathead 1977). Interest-

ingly, North America has contributed relatively few

insects to Europe’s pest fauna. Lindroth (1957)

suggested that North America contributed few spe-

cies to Europe because shipments to Europe con-

tained heavy, raw materials that did not necessitate

ballast, whereas many sailing ships traveling to

North America required ballast because they car-

ried only small cargoes of refined goods.

Less well represented are pests from South

America (10%), and Central America, Mexico, and

the Caribbean region (12%). We might expect that

with the proximity of these regions, and the Neo-

tropical origins of many important crops cultivated

in the United States and Canada (e.g., corn, beans,

squash, potato), we might have a larger contingent

of pests from Latin America. However, the afore-

mentioned values are larger estimates than were de-

veloped by Sailer (1978) for immigrant (invaders

plus deliberate introductions) fauna from these re-

gions (6% for South America, and 7% for Mexico,

Central America, and the Caribbean region). Sailer

suggested that environmental resistance may ac-

count for the relatively small number of Neotropi-

cal pests in North America; invaders from the

Southern Hemisphere are most likely to gain access

to commercial transport during the southern sum-

mer months but may arrive in the Northern Hemi-

sphere during the inhospitable northern winter

months. Evidence for this is perhaps found in the

very high pest invasion rates of Hawaii, Florida,

and California (Sailer 1978, Dowell and Gill 1989,

Frank and McCoy 1992), where environmental re-

sistance is less of an issue for invaders (Sailer 1978).

Asia is well represented as a source of vegetable

pests (18%), although Africa is poorly represented

(6%), and Australia apparently contributed no

pests to North America’s vegetable pest fauna.

The paucity of crops grown in North America

that originate in Africa and Australia, as well as

the relatively low level of commerce between North

America and these continents, may account for

these low figures.

Period of Invasion

Establishment of invading vegetable pests ap-

pears to have reached a maximum in the period of

1850-1899 (Fig. 2). This corresponds to a period

of more rapid transport and increased commerce

between North America and the rest of the world.

However, the date of invasion of a considerable

number of vegetable pests (36%) is uncertain. It is

likely that many pests with unknown dates of in-

vasion were established before 1800 or early in the

1800s, so the apparent increase in rate of invasion

shown in Fig. 2 may be exaggerated. However, the

establishment rate data since 1900 are quite reli-

able, reflecting advances in both the science of en-

tomology and government support for regulatory

activities. Thus, there is good evidence that the rate

of invasion of vegetable pests has declined mark-

edly during the 20th century. There remain in Eu-

rope many important vegetable pests that have not

invaded North America, so I do not think that the

“species pool” of good invaders has been depleted.

In Asia and South America there are even larger

numbers of prospective pests, and the level of

commerce and speed of transport would suggest

that more pests might be introduced successfully.

Thus, the quarantine procedures and eradica-

tion efforts implemented by state and federal

governments are producing benefits for the

United States and Canada, at least with respect

to vegetable pests.

The decreasing rate of establishment of invad-

ing pests reported herein should not be entirely

surprising. Long-term analyses of arthropod in-

troduction rates into California (Dowell and Gill

1989) and Florida (Frank and McCoy 1992,

Florida Department of Agriculture unpublished

data) demonstrate no increase in establishment rate,

despite massive increases in tourism and commerce

between the United States and elsewhere. Those

data and the data reported herein on decreased

vegetable pest invasion rates are hopeful signs, but

hardly signal an end to problems with invading

pests. Not only are invasions continuing, but we

must bear the economic burden of the cumulative

effects of a 300-year period of pest invasion. In an

annoying number of cases, pests that were serious

threats to vegetable production 100 years ago re-

main as significant pests. Thus, the economic bur-

den (costs associated with old and new pests) tends

to increase as new pests establish successfully, even

if the rate of introduction is diminishing and sup-

pressive technology is improving.

Fig. 2. Temporal pattern of invasion of United States and Canada by

vegetable pests (

= 87), expressed as number and percentage in each

time period.

The invasion of large

numbers of European

pests is not limited

to North America, as

it also has occurred

in Australia,

New Zealand,

and South Africa

AMERICAN ENTOMOLOGIST • Volume 48 Number 1 23

Taxa of Invading Pests

The number of vegetable-feeding pests in each

taxon might be expected to reflect the number of

plant-feeding species in that taxon. Indeed, some

of the largest groups of vegetable-feeding species

are in the large plant-feeding orders Coleoptera,

Lepidoptera, Heteroptera, and Homoptera. Also,

the species richness of taxa containing vegetable

pests largely parallels that of pests in general as

documented by the Commonwealth Institute of

Entomology’s world-wide perspective (Simmonds

and Greathead 1977). Specifically, taxa such as the

order Heteroptera, family Aphididae (order

Homoptera), families Pyralidae and Noctuidae (or-

der Lepidoptera), and families Curculionidae and

Scarabaeidae (order Coleoptera), which contain

many pests, also are especially well represented in

the North American vegetable pest compilation.

There are some exceptions, however, and taxa such

as the families Chrysomelidae and Elateridae (or-

der Coleoptera), families Agromyzidae and

Anthomyiidae (order Diptera), family Miridae (or-

der Heteroptera), and family Acrididae (order Or-

thoptera) tend to be slightly over-represented

because North American vegetable pests as com-

pared with pests in general as compiled by the Com-

monwealth Institute of Entomology.

There are some marked differences in taxo-

nomic association of vegetable pests when the abun-

dance of invading organisms is compared with the

abundance of indigenous organisms (Fig. 3). The

proportion of invading Coleoptera, Lepidoptera,

Heteroptera, and Orthoptera is about one-half the

level observed among indigenous species, whereas

Homoptera, Diptera, and Gastropoda are several-

fold more abundant among invaders. The greater

abundance of invading Diptera and Gastropoda is

likely due to the dumping of soil ballast containing

these pests in American ports during the early pe-

riod of colonization when ballast was needed by

sailing ships, because these organisms are com-

monly associated with soil. In contrast, Homoptera

are excellent “hitch-hikers” on plant material, and

many undoubtedly were introduced accidentally

with ornamental plants (Sailer 1978). Some ex-

amples of successful invaders are shown in Fig. 4.

Association of pests into large taxa (i.e., orders

or classes) is convenient, but masks some impor-

tant trends. Family-level analysis suggests some

important differences in biological characteristics

of insects that may account for pest status. The

vegetable-feeding ground beetles (Carabidae), tor-

toise beetles (Chrysomelidae, subfamily Cassidae),

blister beetles (Meloidae), sap beetles (Nitidulidae),

seed bugs (Lygaeidae), woollybears (Arctiidae),

hornworms (Sphingidae), grasshoppers

(Acrididae), and field crickets (Gryllidae) are exclu-

sively indigenous species. The flea beetles

(Chrysomelidae, subfamily Alticinae), wireworms

(Elateridae), cutworms (Noctuidae), and plant bugs

(Miridae) are predominantly indigenous. Possibly

these species are not good “stow-aways,” although

there are other explanations. The European fauna

and the North American fauna are not completely

equivalent, with groups such as grasshoppers

(Acrididae) and wireworms (Elateridae) not par-

ticularly numerous or damaging in Europe, so there

is little likelihood that they would be transported.

Similarly, ground beetles (Carabidae) have been

frequently transported to North America, where

they successfully established (Lindroth 1957), but

few species are considered to be pests. In contrast,

the seed beetles (Bruchidae), mole crickets

(Gryllotalpidae), and nearly all snail and slug (Gas-

tropoda) pests are not indigenous. Invasion by seed

beetles was likely unavoidable due to the depen-

dency of early colonists on legume seeds which

stored well for long periods of time. Mole crickets

and slugs undoubtedly were accidentally intro-

duced with soil ballast (Sailer 1978), though most

snails were deliberately introduced as a source of

food (Mead 1971). Other important taxa con-

taining numerous invaders include the weevils

(Curculionidae), white grubs (Scarabaeidae), root

maggots and leaf miners (Anthomyiidae), and

aphids (Aphididae). The curculionids, scarabaeids,

and anthomyiids have soil-borne or cryptic stages,

and aphids are difficult to detect, especially in the

egg stage, so transport of these groups is under-

standable. Some of the more numerous plant-feed-

ing taxa, including leaf beetles (Chrysomelidae),

leaf miners (Agromyzidae), stalk borers (Pyralidae),

Fig. 3. Taxonomic distribution of invaders (

= 135) and indigenous vegetable pests (

= 197) expressed as

percentage.

24 AMERICAN ENTOMOLOGIST • Spring 2002

Fig. 4. A rogue’s gallery of representative non-indigenous pests affecting North American vegetable crops. Top row (left to right):

beet armyworm, imported cabbageworm, European corn borer. Second row: diamondback moth pupa and larva, asparagus

beetle, Colorado potato beetle. Third row: yellowmargined leaf beetle, whitefringed beetle, Mexican bean beetle. Fourth row:

harlequin bug, southern green stink bug, corn leaf aphids. Bottom row: cabbage aphids, gray garden slug, brown garden snail.

AMERICAN ENTOMOLOGIST • Volume 48 Number 1 25

thrips (Thysanoptera), and mites (Acari) consist

of both indigenous and nonindigenous species.

Again, these groups have below-ground or cryptic

stages.

Feeding Behavior and Damage Frequency

Feeding behavior varies considerably among

both invading and indigenous species. Some spe-

cies attack only a single vegetable crop (e.g., as-

paragus aphid and asparagus, artichoke plume

moth and artichoke, sweetpotato leaf beetle and

sweet potato), others consume 20 or more crops

(e.g., green peach aphid, onion thrips, twostriped

grasshopper), and of course many species are in-

termediate in host acceptance between these ex-

tremes. Of the 332 pests evaluated, 38% were

determined to have a narrow host range (a single

plant family), 16% have a moderate host range

(two to five plant families), and 45% have a wide

host range (more than five plant families). Interest-

ingly, the breadth of host feeding behavior is not

equally distributed among the indigenous and

nonindigenous species. The nonindigenous species

display a greater proportion of species with a nar-

row host range (45%) and a lesser proportion of

species with a wide host range (38%) as compared

to indigenous species (34 and 50%, respectively)

(significant by Fisher’s exact test: P = 0.027). This

trend is even more marked if only the arthropods

are included (the gastropods are excluded); in the

absence of gastropods the invaders’ host range is

50% narrow and 31% wide, and the indigenous

species’ host range is 34% narrow and 50% wide

(Fishers exact test: P < 0.001). From an evolution-

ary perspective, it makes sense that the indigenous

species having a wide host range would be the ones

associated with introduced crops, whereas the in-

vading species that are most intimately associated

with introduced crops (i.e., those with a narrow

host range) would most likely accompany the in-

troduced crops. This is perhaps best seen in the

families Noctuidae and Pyralidae (both order Lepi-

doptera). Noctuid pests of vegetables are over-

whelmingly indigenous, and only 5% are classified

as possessing a narrow host range, whereas 70%

are classified as having a wide host range. The

vegetable pests of the family Pyralidae, however,

are mixed in origin, and 71% are classified as pos-

sessing a narrow host range, whereas 21% have a

wide host range. Thus, the noctuid vegetable pests,

which are overwhelmingly indigenous, have a

broad host range, and the pyralid vegetable pests,

which include a great number of nonindigenous

species, are predominantly narrow in host range

(significantly different by Fisher’s exact test: P <

0.001). A study of adoption of conifer hosts by

British moths (Fraser and Lawton 1994) showed a

similar trend: species adopting new hosts had wider

host ranges. North America possesses close rela-

tives to nearly all the introduced crops among its

indigenous flora, so it might seem equally likely

that specialist herbivores associated with the na-

tive plants would adapt to the introduced crops.

Indeed, we see the results of specialists expanding

their host range to include introduced host plants,

but even more important is the invasion by special-

ist herbivores which are co-evolved and are pre-

adapted to accept the foreign crops.

Damage frequency varies significantly among

indigenous and nonindigenous species, with invad-

ers considered to be damaging far more frequently

(significantly different by Fisher’s exact test: P <

0.001). Among nonindigenous species, 50% were

classified as causing damage rarely and 22% were

classified as causing damage frequently. In contrast,

among indigenous species, 65% were classified as

causing damage rarely and only 9% as causing

damage frequently. Thus, the specialist herbivores

that typify invasive pests are well adapted for their

host plants, and more damaging than the general-

ist indigenous species that have expanded their host

range to include the introduced vegetable crops.

There seems to be no relationship between the site

of attack, or the number of sites attacked on a

plant, and the origin of pests or their frequency of

damage (Appendix 1).

Invading organisms are often thought to be

particularly damaging because they lack the nor-

mal complement of natural enemies found in their

native land. This is largely true, and substantiated

by the decreased abundance and economic impact

of some invaders following introduction of preda-

tors and parasitoids (Sailer 1978). However, the

differing feeding behavior/host range of invaders

relative to indigenous species is perhaps a signifi-

cant element accounting for frequent and damag-

ing outbreaks of nonindigenous species in North

America. Pre-adapted specialist species, with rela-

tively narrow host ranges, are especially well

equipped to exploit crop resources when they are

inadvertently introduced. More than 99% of the

cultivated acreage in North America is planted to

introduced crops, and seems to be unusually vul-

nerable to invading species (Kim 1993).

The importance of herbivore pre-adaptation to

the host, or selective feeding behavior, is not gener-

ally recognized as an important element leading to

frequent damage by invading species, though intu-

itively most economic entomologists would ac-

knowledge its importance. For example, in a review

of the ecological basis for pest problems, Pimentel

(1977) listed numerous factors that account for

pest status, including introduction into new areas

without their natural enemies, change in climatic

regions, monoculture, plant spacing, continuous

culture, plant nutrition, timing of planting, and

pesticide-induced changes in plant physiology.

Though these all are valid elements contributing to

the suitability of host plants to pests, these charac-

teristics are all extrinsic to the pest, representing

climatic and host-plant attributes only. However,

in Pimentel’s discussion of genetic diversity, where

the notion of co-evolution is presented, one begins

to appreciate the significance of plant-insect rela-

tionships, including elements intrinsic to the in-

sects, such as selective feeding behavior. In a later

treatment (Pimentel 1993), food is suggested as

the number one factor in determining success of

Invading organisms

are often thought

to be particularly

damaging because

they lack the normal

complement of

natural enemies

found in their

native land.

26 AMERICAN ENTOMOLOGIST • Spring 2002

invading insects, but again pre-adaptation or feed-

ing specialization is not explicitly stated as a major

factor determining success of, or frequency of dam-

age by, invaders. Similarly, Sakai et al. (2001) re-

viewed the life history characteristics of invasive

species, and although they noted the significance

of pre-adaptation to climatic conditions, they failed

to note the importance of diet specialization. The

lack of data on pest origins, severity, and other

factors perhaps accounts for the under-apprecia-

tion of pre-adaptation or selective feeding behav-

ior as a key element in determining damage by

introduced pests. However, in the biological con-

trol community the importance of selectivity, or

narrow host range due to pre-adaptation, is widely

recognized as an important element in determining

the potential effectiveness (i.e., host location and ex-

ploitation) of introduced biological control agents

(Huffaker et al. 1971, Zwolfer et al. 1976). There is

no reason to expect that the pattern of host-parasite

relationships would be any different in crop plant-

crop pest relationships than it would be in weed-

biological control agent relationships or

insect-parasitoid relationships. The ecological com-

munity also has a good appreciation of pre-adapta-

tion, identifying host plant taxonomic affinity as an

element in host adoption by insect herbivores, and

hence in species richness (Connor et al. 1980,

Neuvonen and Niemela 1983, Capinera et al. 1984b).

Influence of Crop Characteristics on Pest

Species Richness

North American vegetable crops differ greatly

in the extent of commercial acreage, crop value,

and the number of pests associated with each crop

(Capinera 2001). Mean area (+SD) planted to veg-

etable crops averaged 108,000 ha (+150,720 ha)

per crop, ranging from artichoke at only 3,683 ha,

to potato at 662,020 ha. The mean value (+SD) of

vegetable crops was about $617 million (+769

million) or $7,986/ha (+5,785). Correspondingly,

the least valuable crop was artichoke, valued at

$67.6 million, whereas the most valuable was po-

tato, valued at $3,121 million. However, examina-

tion of crop unit value provided a different picture

of vegetable crop worth, with pea the least valuable

crop at $1,162/ha, and celery the most valuable at

$24,340/ha. Vegetable crops averaged (+SD) 110

known pests/crop (+36), with a mean of 39 major

pests (+19) per crop. Although the value and area

planted to crops can vary considerably from year

to year, the pest fauna should display relatively

little short-term change.

Pest species richness was positively related to

area planted to vegetable crops. The number of

indigenous pests, nonindigenous pests, as well as

indigenous plus nonindigenous pests, were signifi-

cantly related to crop area. This was true for both

major pests and all pests (Table 1). Richness of

indigenous species was more directly related to crop

area than was richness of nonindigenous species.

The positive species-area relationship is a fun-

damental expression of community biogeography

(Strong 1979), and is well documented for insects

feeding on trees (Cornell and Washburn 1979;

Claridge and Wilson 1982; MacGarvin 1982;

Stevens 1986; Leather 1985, 1990) and crop plants

(McCoy and Rey 1983; Capinera et al. 1984a,

1984b). However, there is continuing debate con-

cerning the basis for the greater herbivore species

richness associated with more extensive host area

or range. Three general explanations have been

proposed: area per se, habitat heterogeneity, and

passive sampling (Connor and McCoy 1979).

The area per se explanation considers that crop

area is the favorable or preferred habitat for crop

pests, and that when the pests disperse into other

(noncrop) areas their survival is diminished. With

larger crop “islands,” or more extensive plantings,

dispersing insects are more likely to be retained

within the crop habitat, resulting in enhanced sur-

vival and species richness. A dynamic balance is

postulated between immigration and emigration/

extinction, with a higher equilibrium level estab-

lished on larger crop islands or on crops grown

more extensively.

Habitat heterogeneity is greater when crops are

planted over a more extensive area, providing for

differing topological, climatological, or microhabi-

tat differences that may favor accrual of more spe-

cies of herbivores inhabiting the same crop.

Similarly, crops planted more extensively cross the

range limits of more insect species. In an area as

extensive as North America, it is easy to find many

examples of pests that are limited by climatological

factors to a portion of the range inhabited by a

crop. Thus, diversity of physical or biological envi-

ronment rather than equilibrium biogeography is

emphasized in this explanation of the species-area

relationship.

The passive sampling explanation is perceived

as more of a statistical artifact than a biological

explanation. In this scenario, larger crop areas are

thought to accumulate larger numbers of herbivores

through random dispersal, leading to increased spe-

cies richness. Alternatively, crops grown more ex-

tensively may be sampled more frequently or

extensively, leading to greater discovery and the per-

ception of enhanced species richness. Another as-

pect of the sampling explanation is that host species

lists may not be accurate, reflecting collector bias.

Examination of species richness in North Ameri-

can vegetable crops is revealing because it allows us

to dispose of some of the sampling issues effec-

tively. The pest fauna of vegetable crops is well stud-

ied, with extent of research effort and taxonomic

bias not likely to be significant impediments to de-

termination of true host ranges. Also, if there is an

entomologist-based bias, it should be reflected in

relation to crop value. With an entomologist-based

bias we might expect to find vegetable crops of

greater value to be studied more carefully, and to

have longer host lists.

Pest species richness had relatively little relation-

ship to crop value (Table 1). The relationships be-

tween major pest species richness and total crop

value were marginally significant, although when

all pests were considered the relationships were not

AMERICAN ENTOMOLOGIST • Volume 48 Number 1 27

significant. The relationships of pest species rich-

ness and crop value were positive. The marginal

positive relationships are likely due to the fact that,

not surprisingly, crop area and value are corre-

lated (r = 0.758; P < 0.001; n = 20). Thus, pest

species richness and value are auto-correlated but

there is no causative basis. Conversely, when crop

unit values were analyzed, there were no significant

relationships between crop values and the richness

of major pests, and only near significance for crop

values and richness of all pests. These latter relation-

ships were consistently negative. Crops grown ex-

tensively are less valuable, and there is a significant

negative correlation (r = -0.506; P = 0.023; n = 20)

between crop area and unit area values. Again, auto-

correlation accounts for the marginal trends ob-

served with respect to crop unit values and species

richness. In a previous study of crop pests in Colo-

rado, I similarly found no evidence that species rich-

ness was positively correlated with crop value, and

in the case of vegetable crops I found a significant

negative relationship (Capinera et al. 1984a). Thus,

there seems to be little evidence for entomologist-

bias, allowing us to largely exclude sampling-based

explanations for the species-area relationships

It is difficult to determine the relative contribu-

tion of the two remaining explanations, area per se

and habitat heterogeneity, to species richness. As

pointed out by Strong (1979), heterogeneity is of-

ten correlated with area. However, heterogeneity

seems the most logical basis for the species-area

relationship. Many crop pests, particularly special-

ists, are adept at locating small patches of plants,

even including individual plants. Also, the vegetable

crops in North America have had 200 years or

more to be “located” by indigenous insect herbi-

vores, so relationships should be fairly well de-

fined. Lastly, because of the extensive observations

of vegetable crops made in North America during

the last 150 years, there are few undiscovered rela-

tionships/host associations. There seems to be little

evidence, therefore, to justify area per se as the basis

for species richness unless higher extinction rates in

smaller “patches” leads to failure of entomologists

to detect colonizing species. On the other hand, habi-

tat heterogeneity is a significant element affecting

species distribution. Northern and southern lati-

tudes differ markedly with respect to vegetable fauna,

and a moisture-based longitudinal gradient also af-

fects host associations significantly in North America.

Plant species grown more extensively will undoubt-

edly accrue longer host lists on a continent as clima-

tologically diverse as North America.

Crop area is not the only plant characteristic to

affect species richness. The architecture or com-

plexity of plants (Lawton 1983), taxonomic relat-

edness (Connor et al. 1980, Niemela and Neuvonen

1983, Kennedy and Southwood 1984), and de-

gree of polyphagy and habitat generalism (Quinn

et al. 1997) have been implicated, though these

factors are usually less important than is area. In a

previous analysis of crop plants grown in Colo-

rado, I found that the plant architecture and taxo-

nomic relatedness factors affected species richness

on crop plants, but not in a consistent manner

(Capinera et al. 1984a).

Characterization of North American

Vegetable Pests

Of the 332 pests considered to be damaging to

vegetable crops in the United States and Canada,

59% apparently are indigenous. The invaders come

principally from Europe, the source of many of

our vegetable and ornamental crops, the major

Table 1. Regression equations describing the relationship (log/log) of species richness (number of pests

per crop) to crop area (ha), crop value ($), and unit value ($/ha)

XYEquation Residual mean square Fr2P

Area Major pests, indigenous Y = (0.38)X - 0.54 0.071 10.18 0.361 0.005**

Major pests, invaders Y = (0.19)X + 0.22 0.035 5.32 0.228 0.033*

Major pests, total Y = (0.31)X + 0.07 0.039 11.83 0.396 0.003**

All pests, indigenous Y = (0.22)X + 0.78 0.025 9.63 0.348 0.006**

All pests, invaders Y = (0.22)X + 0.50 0.032 7.58 0.296 0.013*

All pests, total Y = (0.22)X + 0.95 0.027 9.18 0.337 0.007**

Crop value Major pests, indigenous Y = (0.29)X + 0.53 0.094 3.45 0.161 0.079

Major pests, invaders Y = (0.18)X + 0.67 0.039 3.09 0.147 0.094

Major pests, total Y = (0.25)X + 0.90 0.054 4039 0.196 0.050*

All pests, indigenous Y = (0.08)X + 1.60 0.038 0.63 0.034 0.438

All pests, invaders Y = (0.19)X + 1.15 0.040 2.07 0.116 0.141

All pests, total Y = (0.31)X + 1.62 0.036 2.39 0.117 0.139

Unit value Major pests, indigenous Y = (-0.33)X + 2.54 0.978 2.56 0.124 0.127

Major pests, invaders Y = (-0.19)X + 1.85 0.041 1.91 0.096 0.184

Major pests, total Y = (-0.27)X + 2.55 0.056 2.87 0.137 0.107

All pests, indigenous Y = (-0.23)X + 2.70 0.031 3.92 0.176 0.063

All pests, invaders Y = (-0.21)X + 2.36 0.041 2.48 0.121 0.132

All pests, total Y = (-0.23)X + 2.88 0.034 3.48 0.162 0.078

*, significant; **, highly significant

28 AMERICAN ENTOMOLOGIST • Spring 2002

source of human immigrants that populated North

America, and a continuing source of tourists and

trade. Latin America and Asia are secondarily im-

portant as sources of vegetable pests, though they

remain significant potential sources of invaders.

The rate of invasion by vegetable pests has de-

creased in the 20th century, though pests continue

to enter North America. The regulatory processes

developed to curtail the influx of exotic pests seem

to have had considerable benefit.

The major plant-feeding insect orders are well

represented among North American vegetable

pests, principally the orders Coleoptera, Lepi-

doptera, Heteroptera and Homoptera. Invaders

are more likely to be the orders Homoptera and

Diptera, and the class Gastropoda, whereas indig-

enous pests are more likely to be the orders Co-

leoptera, Lepidoptera, Heteroptera, and Orthoptera.

Among the groups that are particularly good

invaders are the insect families Bruchidae,

Curculionidae, and Scarabaeidae (all order Co-

leoptera), family Pyralidae (order Lepidoptera), fam-

ily Anthomyiidae (order Diptera), family Aphididae

(order Homoptera), family Gryllotalpidae (order

Orthoptera), and the class Gastropoda. We seem to

be at greatest risk from pests that have soil-dwelling

or cryptic stages, as these pests gain entry frequently.

North American vegetable crops have numerous

pests, averaging 110 per crop, and with a mean of

39 major pests per crop.

Invading vegetable pests are more likely to have

a narrow host range (a single vegetable plant fam-

ily) whereas indigenous pests are more likely to

have a wide host range (more than five plant fami-

lies). Nonindigenous pests are more likely to be

classified as serious pests than are indigenous pests.

Thus, preadaptation to feed on imported vegetable

crops is identified as a major factor in attainment

of pest status. Species richness of both indigenous

and nonindigenous vegetable crop pests is posi-

tively related to the extent of commercial crop pro-

duction in North America, so the crops most at

risk of acquiring new pests are those grown most

extensively. Although economics usually determines

whether or not an insect is considered to be serious

pest, crop values do not affect our perception of

pest species richness.

Acknowledgments

This research was supported by the Florida Ag-

ricultural Experiment Station, and approved for

publication as Journal Series No. R-08132. J. H.

Frank, R. McSorley, and J. R. Rey kindly provided

useful reviews of the manuscript.

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John Capinera is Professor of Entomology and

Chairman of the Entomology and Nematology De-

partment at the University of Florida, Gainesville

FL (jlcap@mail.ifas.ufl.edu). Since his graduate

school days he has had an interest in vegetable

pests, and recently authored a new reference, Hand-

book of Vegetable Pests (Academic 2001), a com-

prehensive review of pests affecting vegetable crops

in the United States and Canada. He moved to

Florida in 1987, where he gained a new apprecia-

tion for invasive insects, as this state is “blessed”

with the establishment of about 12 new insects

annually. John’s other favorite research topic is

grasshoppers, and he and his students recently

published a new book, Grasshoppers of Florida

(University Press of Florida 2001). 7

Appendix continued on next page

Appendix 1. Insects and other invertebrate pests affecting vegetable crops in the United States and Canada

Status Origin Host Period of Damage Site

range detection frequency damaged

Order Coleoptera - beetles, weevils, white grubs, and wireworms

Family Bruchidae - seed beetles and weevils

Acanthoscelides obtectus (Say), bean weevil Invader Central America, Narrow 1800-1850 Rare Fruit

Mexico, Caribbean

Bruchus pisorum (L.), pea weevil Invader Africa Narrow Before 1800 Rare Fruit

Bruchus rufimanus Boheman, broadbean weevil Invader Asia Narrow 1850-1900 Rare Fruit

Callosobruchus chinensis (L.), southern cowpea weevil Invader Africa Narrow ? Rare Fruit

Callosobruchus maculatus (F.), cowpea weevil Invader Africa Narrow 1800-1850 Rare Fruit

Family Carabidae—ground beetles

Clivina impressifrons LeConte, slender seedcorn beetle Native Narrow Rare Root/

seed/bulb

Stenolophus comma (F.), seedcorn beetle Native Narrow Periodic Root/

seed/bulb

Stenolophus lecontei (Chaudoir), seedcorn beetle Native Narrow Rare Root/

seed/bulb

Family Chrysomelidae, subfamily Alticinae - flea beetles

Chaetocnema confinis Crotch, sweetpotato flea beetle Native Moderate Rare Foliage, root/

seed/bulb

30 AMERICAN ENTOMOLOGIST • Spring 2002

Appendix 1. (continued)

Status Origin Host Period of Damage Site

range detection frequency damaged

Order Coleoptera - beetles, weevils, white grubs, and wireworms (continued)

Chaetocnema denticulata (Illiger), toothed flea beetle Native Narrow Rare Foliage

Chaetocnema ectypa Horn, desert corn flea beetle Native Moderate Rare Foliage, root/

seed/bulb

Chaetocnema pulicaria Melsheimer, corn flea beetle Native Narrow Periodic Foliage

Disonycha mellicollis Say, yellownecked flea beetle Native Narrow Rare Foliage

Disonycha triangularis (Say), threespotted flea beetle Native Narrow Rare Foliage

Disonycha xanthomelas (Dalman), spinach flea beetle Native Narrow Rare Foliage

Epitrix cucumeris (Harris), potato flea beetle Native Wide Rare Foliage,

tuber, root/

seed/bulb

Epitrix fasciata Blatchley, Invader Central America, Moderate ? Rare Foliage, root/

southern tobacco flea beetle Mexico, Caribbean seed/bulb

Epitrix fuscula Crotch, eggplant flea beetle Native Narrow Periodic Foliage, tuber,

root/seed/bulb

Epitrix hirtipennis (Melsheimer), tobacco flea beetle Native Moderate Periodic Foliage, root/

seed/bulb

Epitrix subcrinata LeConte, western potato flea beetle Native Wide Rare Foliage, tuber,

root/seed/bulb

Epitrix tuberis Gentner, tuber flea beetle Native Wide Periodic Foliage, tuber,

root/seed/bulb

Phyllotreta albionica LeConte, cabbage flea beetle Native Narrow Rare Foliage, root/

seed/bulb

Phyllotreta armoraciae (Koch), horseradish flea beetle Invader Europe Narrow 1850-1900 Rare Foliage, root/

seed/bulb

Phyllotreta cruciferae (Goeze), crucifer flea beetle Invader Europe Moderate 1900-1950 Frequent Foliage, root/

seed/bulb

Phyllotreta pusilla Horn, western black flea beetle Native Wide Rare Foliage, root/

seed/bulb

Phyllotreta ramosa (Crotch), Native Narrow Rare Foliage, root/

western striped flea beetle seed/bulb

Phyllotreta striolata (F.), striped flea beetle Invader Europe Narrow Before 1800 Periodic Foliage, root/

seed/bulb

Phyllotreta zimmermanni (Crotch), Invader Moderate ? Rare Foliage

Zimmermann’s flea beetle

Psylliodes punctulata Melsheimer, hop flea beetle Native Wide Rare Foliage

Systena blanda Melsheimer, palestriped flea beetle Native Wide Periodic Foliage, root/

seed/bulb

Systena elongata (F.), elongate flea beetle Native Wide Rare Foliage, root/

seed/bulb

Systena frontalis (F.), redheaded flea beetle Native Wide Rare Foliage, root/

seed/bulb

Systena hudsonias (Förster), smartweed flea beetle Native Wide Rare Foliage, root/

seed/bulb

Family Chrysomelidae, subfamily Cassidinae -

tortoise beetles

Agroiconota bivittata (Say), striped tortoise beetle Native Narrow Rare Foliage

Charidotella bicolor (F.), golden tortoise beetle Native Narrow Rare Foliage

Chelymorpha cassidea (L.), argus tortoise beetle Native Narrow Rare Foliage, root/

seed/bulb

Deloyala guttata (Olivier), mottled tortoise beetle Native Narrow Rare Foliage

Gratiana pallidula (Boheman), eggplant tortoise beetle Native Narrow Rare Foliage

Jonthonota nigripes (Olivier), Native Narrow Rare Foliage

blacklegged tortoise beetle

Family Chrysomelidae, several subfamilies -

leaf beetles

Acalymma trivittatum (Mannerheim), Native Wide Periodic Blossom,

western striped cucumber beetle fruit, foliage,

root/seed/bulb

Acalymma vittatus (F.), striped cucumber beetle Native Wide Frequent Blossom,

fruit, foliage,

root/seed/bulb

Cerotoma trifurcata (Förster), bean leaf beetle Native Narrow Rare Foliage, root/

seed/bulb

Colaspis brunnea (F.), grape colaspis Native Wide Rare Foliage, root/

seed/bulb

Crioceris asparagi (L.), asparagus beetle Invader Europe Narrow 1850-1900 Periodic stem/vine,

foliage

AMERICAN ENTOMOLOGIST • Volume 48 Number 1 31

Crioceris duodecimpunctata (L.), Invader Europe Narrow 1850-1900 Periodic Fruit, foliage

spotted asparagus beetle

Diabrotica balteata LeConte, Native Wide Periodic Blossom, fruit,

banded cucumber beetle foliage, tuber,

root/seed/bulb

Diabrotica barberi Smith & Lawrence, Native Moderate Rare Root/

northern corn rootworm seed/bulb

Diabrotica undecimpunctata Mannerheim, Native Wide Frequent Blossom,

spotted cucumber beetle fruit, foliage,

root/seed/

bulb

Diabrotica virgifera LeConte, Native Moderate Frequent Blossom,

western corn rootworm fruit, foliage,

root/seed/

bulb

Entomoscelis americana Brown, red turnip beetle Native Narrow Rare Stem/vine,

foliage

Leptinotarsa decemlineata (Say), Invader Central America, Narrow 1800-1850 Frequent

Colorado potato beetle Mexico, Caribbean Foliage

Microtheca ochroloma Stål, yellowmargined leaf beetle Invader South America Wide 1900-1950 Periodic Foliage

Typophorus nigritus (Crotch), sweetpotato leaf beetle Native Narrow Rare Stem/vine,

foliage,

tuber, root/

seed/bulb

Family Curculionidae - billbugs, curculios, and weevils

Anthonomus eugenii Cano, pepper weevil Invader Central America, 1900-1950 Frequent Blossom,

Mexico, Caribbean fruit

Ceutorhynchus assimilis (Paykull), Invader Europe 1900-1950 Rare Fruit

cabbage seedpod weevil

Ceutorhynchus rapae Gyllenhal, cabbage curculio Invader Europe 1800-1850 Rare Stem/vine,

foliage

Chalcodermus aeneus Boheman, cowpea curculio Native Periodic Blossom

Cylas formicarius (Summers), sweetpotato weevil Invader Africa 1850-1900 Frequent Foliage,

tuber

Diaprepes abbreviatus (L.), Invader Central America, 1950-present Rare tuber

West Indian sugarcane rootstalk borer weevil Mexico, Caribbean

Listroderes difficilis Germar, vegetable weevil Invader South America 1900-1950 Periodic Foliage,

root/seed/

bulb

Listronotus oregonensis (LeConte), carrot weevil Native Frequent Stem/vine,

root/seed/

bulb

Listronotus texanus (Stockton), Texas carrot weevil Native Periodic Stem/vine,

root/seed/

bulb

Lixus concavus Say, rhubarb cuculio Native Rare Stem/vine,

foliage

Naupactus spp., whitefringed beetle Invader South America 1900-1950 Periodic Foliage,

tuber, root/

seed/bulb

Sitona lineatus (L.), pea leaf weevil Invader Europe 1900-1950 Periodic Foliage,

root/seed/

bulb

Sphenophorus callosus (Oliver), southern corn billbug Native Rare Stem/vine,

root/seed/

bulb

Sphenophorus maidis Chittenden, maize billbug Native Rare Stem/vine,

root/seed/

bulb

Trichobaris trinotata (Say), potato stalk borer Native Rare Stem/vine,

foliage

Family Coccinellidae - lady beetles

Epilachna borealis F., squash beetle Native Rare Foliage

Epilachna varivestris Mulsant, Invader Central America, Before 1800 Frequent Foliage

Mexican bean beetle Mexico, Caribbean

Family Elateridae - click beetles and wireworms

Agriotes mancus (Say), wheat wireworm Native Rare Tuber, root/

seed/bulb

Conoderus amplicollis (Gyllenhal), Invader South America 1900-1950 Periodic Stem/vine,

Status Origin Host Period of Damage Site

range detection frequency damaged

Appendix continued on next page

32 AMERICAN ENTOMOLOGIST • Spring 2002

Gulf wireworm tuber, root/

seed/bulb

Conoderus falli Lane, southern potato wireworm Invader South America 1900-1950 Periodic Stem/vine,

tuber, root/

seed/bulb

Conoderus vespertinus (F.), tobacco wireworm Native Periodic Stem/vine,

tuber, root

/seed/bulb

Ctenicera aeripennis aeripennis (Kirby), Native Rare Tuber, root/

Puget Sound wireworm seed/bulb

Ctenicera aeripennis destructor (Brown), Native Rare Tuber, root/

prairie grain wireworm seed/bulb

Ctenicera glauca (Germar), dryland wireworm Native Rare Tuber, root/

seed/bulb

Ctenicera pruinina (Horn), Great Basin wireworm Native Rare Tuber, root/

seed/bulb

Limonius agonus (Say), eastern field wireworm Native Periodic Tuber, root/

seed/bulb

Limonius californicus (Mannerheim), Native Periodic Tuber, root/

sugarbeet wireworm seed/bulb

Limonius canus LeConte, Pacific Coast wireworm Native Periodic Tuber, root/

seed/bulb

Melanotus communis (Gyllenhal), corn wireworm Native Periodic Root/seed/

bulb

Melanotus longulus oregonensis (LeConte), Native Rare Root/seed/

Oregon wireworm bulb

Family Meloidae - blister beetles

Epicauta immaculata (Say), immaculate blister beetle Native Rare Blossom,

foliage

Epicauta maculata (Say), spotted blister beetle Native Rare Blossom,

foliage

Epicauta pensylvanica (De Geer), black blister beetle Native Periodic Blossom,

foliage

Epicauta vittata (F.), striped blister beetle Native Periodic Blossom,

foliage

Family Nitidulidae - sap beetles

Carpophilus lugubris Murray, dusky sap beetle Native Rare Fruit

Glischrochilus quadrisignatus (Say), Native Periodic Fruit

fourspotted sap beetle

Family Scarabaeidae - scarab beetles

and white grubs

Adoretus sinicus Burmeister, Chinese rose beetle Invader Asia 1850-1900 Rare Foliage

Anomala orientalis Waterhouse, oriental beetle Invader Asia 1900-1950 Rare Foliage, root/

seed/bulb

Bothynus gibbosus (De Geer), carrot beetle Native Rare Root/seed/

bulb

Cotinis nitida (L.), green June beetle Native Rare Foliage, root/

seed/bulb

Macrodactylus subspinosus (F.), rose chafer Native Rare Blossom,

fruit, foliage

Macrodactylus uniformis Horn, western rose chafer Native Rare Blossom,

fruit, foliage

Maladera castanea (Arrow), Asiatic garden beetle Invader Asia 1900-1950 Rare Foliage, root/

seed/bulb

Phyllophaga and others, white grubs Native Periodic Root/seed/bulb

Popillia japonica Newman, Japanese beetle Invader Asia 1900-1950 Frequent Fruit, foliage,

root/seed/

bulb

Strigoderma arboricola (F.), spring rose beetle Native Rare Root/seed/

bulb

Family Tenebrionidae - darking beetles

and false wireworms

Blapstinus, Coniontis, Eleodes, and Ulus spp., Native Rare Stem/vine,

false wireworms tuber, root/

seed/bulb

Appendix 1. (continued)

Status Origin Host Period of Damage Site

range detection frequency damaged

Order Coleoptera - beetles, weevils, white grubs, and wireworms (continued)

AMERICAN ENTOMOLOGIST • Volume 48 Number 1 33

Order Dermaptera - Earwigs

Euborellia annulipes (Lucas), ringlegged earwig Invader Europe 1900-1950 Periodic Fruit, foliage

Forficula auricularia L., European earwig Invader Europe 1850-1900 Rare Foliage,

tuber, root/

seed/bulb

Order Diptera - Flies and Maggots

Family Agromyzidae - leafminer flies

Agromyza parvicornis Loew, corn blotch leafminer Native Rare Foliage

Liriomyza brassicae (Riley), cabbage leafminer Invader ? ? Rare Foliage

Liriomyza huidobrensis (Blanchard), pea leafminer Invader? South America ? Periodic Foliage

Liriomyza sativae Blanchard, vegetable leafminer Invader? South America ? Rare Foliage

Liriomyza trifolii (Burgess), Native Periodic Foliage

American serpentine leafminer

Ophiomyia simplex (Loew), asparagus miner Invader Europe 1850-1900 Rare Stem/vine

Family Anthomyiidae - root and seed maggots,

leafminer flies

Delia antiqua (Meigen), onion maggot Invader Europe Before 1800 Frequent Stem/vine,

root/

seed/bulb

Delia floralis (Fallén), turnip maggot Invader? Europe ? Periodic Root/seed/

bulb

Delia florilega (Zetterstedt), bean seed maggot Invader Europe ? Rare Root/seed/

bulb

Delia planipalpis (Stein), radish root maggot Native Rare Root/seed/

bulb

Delia platura (Meigen), seedcorn maggot Invader Europe 1850-1900 Periodic Root/seed/

bulb

Delia radicum (L.), cabbage maggot Invader Europe 1800-1850 Frequent Stem/vine,

root/seed/

bulb

Pegomya betae Curtis, beet leafminer Invader Europe 1800-1850 Frequent Foliage

Pegomya hyoscyami (Panzer), spinach leafminer Invader Europe 1800-1850 Frequent Foliage

Family Drosophilidae - pomace flies

Drosophila spp., small fruit flies Invader? South America ? Rare Fruit

Family Otididae - picturewing flies

Euxesta stigmatias Loew, cornsilk fly Invader Central America, ? Periodic Fruit

Mexico, Caribbean

Tetanops myopaeformis (Roeder), Native Rare Root/seed/

sugarbeet root maggot bulb

Family Psilidae - rust flies

Psila rosae (F.), carrot rust fly Invader Europe 1850-1900 Frequent Root/seed/

bulb

Family Syrphidae - flower and bulb flies

Eumerus strigatus (Fallén), onion bulb fly Invader Europe 1850-1900 Rare Root/seed/

bulb

Eumerus tuberculatus Rondani, lesser bulb fly Invader Europe 1850-1900 Rare Root/seed/

bulb

Family Tephritidae - fruit flies

Bactrocera cucurbitae Coquillett, melon fly Invader Asia 1850-1900 Frequent Blossom,

fruit, stem/

vine

Bactrocera dorsalis Hendel, oriental fruit fly Invader Asia 1900-1950 Frequent Fruit

Euleia fratria (Loew), parsnip leafminer Native Rare Foliage

Zonosemata electa (Say), pepper maggot Native Periodic Fruit

Family Tipulidae - crane flies

Tipula paludosa Meigen, European crane fly Invader Europe 1950-present Stem/vine,

foliage, root/

seed/bulb

Order Heteroptera - Bugs

Family Coreidae - squash and leaffooted bugs

Anasa armigera (Say), horned squash bug Native? Rare Fruit, foliage

Anasa tristis (De Geer), squash bug Native? Frequent Fruit, foliage

Appendix continued

Status Origin Host Period of Damage Site

range detection frequency damaged

34 AMERICAN ENTOMOLOGIST • Spring 2002

Leptoglossus spp., leaffooted bugs Native Frequent Fruit, foliage

Family Cydnidae - burrower bugs

Pangaeus bilineatus (Say), burrowing bug Native Rare Fruit, foliage

Family Lygaeidae - seed bugs

Blissus leucopterus (Say), chinch bugs Native Rare Foliage

Nysius niger Baker, false chinch bug Native Periodic Foliage

Nysius raphanus Howard, false chinch bug Native Periodic Foliage

Family Miridae - plant bugs

Adelphocoris lineolatus (Goeze), alfalfa plant bug Invader Europe 1900-1950 Rare Blossom,

foliage

Adelphocoris rapidus (Say), rapid plant bug Native Rare Blossom,

foliage

Adelphocoris superbus (Uhler), superb plant bug Native Rare Blossom,

foliage

Halticus bractatus (Say), garden fleahopper Native Periodic Foliage

Lygus elisus Van Duzee, pale legume bug Native Rare Blossom,

fruit, stem/

vine, foliage

Lygus hesperus Knight, western tarnished plant bug Native Periodic Blossom,

fruit, stem/

vine, foliage

Lygus lineolaris (Palisot de Beauvois), Native Frequent Blossom,

tarnished plant bug fruit, stem/

vine, foliage

Orthops scutellatus Uhler, carrot plant bug Invader Europe 1900-1950 Rare Blossom,

fruit, foliage

Family Pentatomidae - stink bugs

Acrosternum hilare (Say), green stink bug Native Rare Fruit, foliage

Chlorochroa sayi (Stål), Say stink bug Native Rare Blossom, fruit,

stem/vine

Chlorochroa uhler (Stol), Uhler stink bug Native Rare

Euschistus conspersus Uhler, consperse stink bug Native Periodic Fruit

Euschistus servus (Say), brown stink bug Native? Rare Blossom,

fruit, stem/

vine

Euschistus variolaris (Palisot de Beauvois), Native Rare Blossom,

onespotted stink bug fruit, foliage

Murgantia histrionica (Hahn), harlequin bug Invader Central America, 1850-1900 Periodic Foliage

Mexico, Caribbean

Nezara viridula (L.), southern green stink bug Invader Africa Before 1800 Frequent Blossom,

fruit, stem/

vine, tuber

Family Thyreocoridae - Negro bugs

Corimelaena pulicaria (Germar), little black bug Native Rare Stem/

vine, foliage

Family Tingidae - lace bugs

Gargaphia solani Heideman, eggplant lace bug Native Rare Foliage

Order Homoptera - Aphids, Leaf- and Planthoppers, Psyllids and Whiteflies

Family Aleyrodidae - whiteflies

Bemisia argentifolii Bellows & Perring, Invader ? 1950-present Frequent Foliage

silverleaf whitefly

Bemisia tabaci (Gennadius), sweetpotato whitefly Invader ? 1900-1950 Rare Foliage

Trialeurodes vaporariorum Invader Central America, Periodic Foliage

(Westwood), greenhouse whitefly Mexico, Caribbean

Family Aphididae - aphids

Acyrthosiphon kondoi Shinji, blue alfalfa aphid Invader Asia 1950-present Rare Blossom,

fruit, stem/

vine, foliage

Acyrthosiphon pisum (Harris), pea aphid Invader Europe 1850-1900 Periodic Blossom,

fruit, stem/

vine, foliage

Aphis craccivora Koch, cowpea aphid Invader Africa? ? Periodic Fruit, stem/

Appendix 1. (continued)

Status Origin Host Period of Damage Site

range detection frequency damaged

Order Heteroptera - Bugs (continued)

AMERICAN ENTOMOLOGIST • Volume 48 Number 1 35

vine, foliage

Aphis fabae Scopoli, bean aphid Invader Europe ? Periodic Foliage

Aphis gossypii Glover, melon aphid Invader? ? ? Frequent Foliage

Aphis maidiradicis Forbes, corn root aphid Native Rare Root/seed/

bulb

Aphis nasturtii Kaltenbach, buckthorn aphid Invader Europe? ? Periodic Foliage

Aulacorthum solani (Kaltenbach), foxglove aphid Invader Europe? ? Rare Foliage

Brachycorynella asparagi (Mordvilko), Invader Europe 1950-present Frequent Foliage

asparagus aphid

Brevicoryne brassicae (L.), cabbage aphid Invader Europe? Before 1800 Frequent Foliage

Capitophorus elaeagni (del Guercio), artichoke aphid Invader Europe ? Periodic Foliage

Cavariella aegopodii Scopoli, willow-carrot aphid Invader ? ? Frequent Foliage

Dysaphis crataegi (Kaltenbach), carrot root aphid Invader Europe ? Rare Stem/vine,

root/seed/

bulb

Dysaphis foeniculus (Theobald), carrot root aphid Invader Europe ? Rare Stem/vine,

root/seed/

bulb

Hyadaphis coriandri (Das), coriander aphid Invader Europe 1950-present Rare Foliage

Hyadaphis foeniculi (Passerini), honeysuckle aphid Invader Europe 1900-1950 Rare Foliage

Lipaphis erysimi (Kaltenbach), turnip aphid ? Periodic Foliage

Macrosiphum euphorbiae (Thomas), potato aphid Native Frequent Stem/vine,

foliage

Myzus persicae (Sulzer), green peach aphid Invader ? ? Frequent Foliage

Nasonovia ribisnigri (Mosley), lettuce aphid Invader Europe 1950-present Periodic Foliage

Pemphigus betae Doane, sugarbeet root aphid Native Rare Root/seed/

bulb

Pemphigus bursarius (L.), lettuce root aphid Invader Europe ? Periodic Root/seed/

bulb

Pemphigus populivenae Fitch, sugarbeet root aphid Native Rare Root/seed/

bulb

Rhopalosiphum maidis (Fitch), corn leaf aphid Invader Asia? ? Rare Blossom,

fruit, foliage

Rhopalosiphum padi (L.), bird cherry-oat aphid Native Periodic Foliage

Rhopalosiphum rufiabdominalis (Saaki), Invader Asia ? Rare Root/seed/

rice root aphid bulb

Smynthurodes betae Westwood, bean root aphid Invader Europe ? Rare Root/seed/

bulb

Family Cicadellidae - leafhoppers

Circulifer tenellus (Baker), beet leafhopper Invader Europe Before 1800 Frequent Foliage

Dalbulus maidis (DeLong & Wolcott), Invader Central America, ? Periodic Foliage

corn leafhopper Mexico, Caribbean

Empoasca abrupta Delong, western potato leafhopper Native Rare Foliage

Empoasca fabae (Harris), potato leafhopper Native Periodic Foliage

Macrosteles quadrilineatus Forbes, aster leafhopper Native Frequent Foliage

Family Delphacidae - planthoppers

Peregrinus maidis (Ashmead), corn delphacid Invader Africa ? Rare Foliage

Family Psyllidae - psyllids

Paratrioza cockerelli (Sulc), potato psyllid Native Periodic Foliage

Order Hymenopters - Ants and Sawflies

Family Argidae - sawflies

Sterictiphora cellularis (Say), sweetpotato sawfly Native Rare Foliage

Family Formicidae - ants

Solenopsis invicta Buren, red imported fire ant Invader South America 1900-1950 Periodic Fruit, stem/

vine, foliage,

tuber, root/

seed/bulb

Order Lepidoptera - Caterpillars, Moths and Butterflies

Family Arctiidae - woollybear caterpillars

and tiger moths

Estigmene acrea (Drury), saltmarsh caterpillar Native Periodic Foliage

Pyrrharctia isabella (J.E. Smith), banded woollybear Native Rare Foliage

Spilosoma virginica (F.), yellow woollybear Native Rare Foliage

Status Origin Host Period of Damage Site

range detection frequency damaged

Appendix continued

36 AMERICAN ENTOMOLOGIST • Spring 2002

Family Gelechiidae - leafminer moths

Keiferia lycopersicella (Walsingham), Invader Central America, 1900-1950 Frequent Fruit, foliage

tomato pinworm Mexico, Caribbean

Phthorimaea operculella (Zeller), potato tuberworm Native Periodic Foliage, tuber

Tildenia inconspicuella (Murtfeldt), eggplant leafminer Native Rare Foliage

Family Hesperiidae - skipper butterflies

Urbanus proteus (L.), bean leafroller Native Periodic Foliage

Family Lycaenidae - hairstreak butterflies

Strymon melinus (Hübner), cotton square borer Native Rare Fruit, foliage

Family Lyonetiidae - lyonetiid moths

Bedellia orchilella Walsingham, Invader Asia ? Rare Foliage

sweetpotato leafminer

Bedellia somnulentella (Zeller), Invader Asia ? Rare Foliage

morningglory leafminer

Family Noctuidae - armyworms, cutworms, loopers,

stalk borers, and nocutid moths

Agrotis ipsilon (Hufnagel), black cutworm Native Periodic Foliage

Agrotis orthogonia Morrison, pale western cutworm Native Rare Stem/vine

Agrotis subterranea (F.), granulate cutworm Native Periodic Stem/vine,

foliage

Anagrapha falcifera (Kirby), celery looper Native Rare Foliage

Anomis erosa Hübner, okra caterpillar Invader? ? ? Rare Foliage

Apamea devastator (Brace), glassy cutworm Native Rare Stem/vine,

root/seed/

bulb

Autographa californica (Speyer), alfalfa looper Native Periodic Foliage

Autographa precationis (Guenée), plantain looper Native Rare Foliage

Autoplusia egena (Guenée), bean leafskeletonizer Native Rare Foliage

Dicestra trifolii (Hufnagel), clover cutworm Native Periodic Foliage

Euxoa auxiliaris (Grote), army cutworm Native Rare Stem/vine,

foliage

Euxoa messoria (Harris), darksided cutworm Native Rare Foliage

Euxoa ochrogaster (Guenée), redbacked cutworm Native Periodic Stem/vine,

foliage

Feltia jaculifera (Guenée), dingy cutworm Native Rare Foliage

Feltia subgothica (Haworth), dingy cutworm Native Rare Foliage

Helicoverpa zea (Boddie), corn earworm Native Frequent Fruit, foliage

Heliothis virescens (F.), tobacco budworm Native Rare Blossom, fruit,

stem/vine

Hydraecia immanis (Guenée), hop vine borer Native Periodic Stem/vine,

foliage, root/

seed/bulb

Hydraecia micacea (Esper), potato stem borer Invader Europe 1900-1950 Periodic Stem/vine,

foliage, root/

seed/bulb

Loxagrotis albicosta (Smith), western bean cutworm Native Rare Fruit

Mamestra configurata Walker, bertha armyworm Native Periodic Foliage

Megalographa biloba (Stephens), bilobed looper Native Rare Foliage

Melanchra picta (Harris), zebra caterpillar Native Rare Foliage

Mocis latipes Guenée, striped grass looper Native Rare Foliage

Nephelodes minians Guenée, bronzed cutworm Native Rare Foliage

Papaipema nebris (Guenée), stalk borer Native Rare stem/vine

Peridroma saucia (Hübner), variegated cutworm Invader Europe? 1800-1850 Periodic Stem/vine,

foliage

Plathypena scabra (F.), green cloverworm Native Rare Foliage

Pseudaletia unipunctata (Haworth), armyworm Native Periodic Foliage

Pseudoplusia includens (Walker), soybean looper Native Rare Fruit, foliage

Spodoptera dolichos (F.), sweetpotato armyworm Native Rare Stem/vine,

foliage

Spodoptera eridania (Stoll), southern armyworm Native Frequent Fruit, foliage,

tuber

Spodoptera exigua (Hübner), beet armyworm Invader Asia 1850-1900 Frequent Foliage

Spodoptera frugiperda (J.E. Smith), fall armyworm Native Frequent Fruit, foliage

Appendix. (continued)

Status Origin Host Period of Damage Site

range detection frequency damaged

Order Lepidoptera - Caterpillars, Moths and Butterflies (continued)

AMERICAN ENTOMOLOGIST • Volume 48 Number 1 37

Spodoptera latifascia (Walker), velvet armyworm Native Rare Stem/vine,

foliage

Spodoptera ornithogalli (Guenée), Native Periodic Fruit, foliage

yellowstriped armyworm

Spodoptera praefica (Grote), Native Periodic Fruit, foliage

western yellowstriped armyworm

Trichoplusia ni (Hübner), cabbage looper ? Frequent Foliage

Xestia adela Franclemont, spotted cutworm Invader Europe ? Periodic Fruit, stem/

vine, foliage

Xestia dolosa Franclemont, spotted cutworm Invader Europe ? Periodic Fruit, stem/

vine, foliage

Family Oecophoridae - oecophorid moths

Depressaria pastinacella (Duponchel), Invader Europe 1850-1900 Rare Blossom

parsnip webworm

Family Papilionidae - celeryworms and

swallowtail butterflies

Papilio polyxenes F., black swallowtail Native Rare Foliage

Papilio zelicaon Lucas, anise swallowtail Native Rare Foliage

Family Pieridae - cabbageworms, white, and

sulfur butterflies

Ascia monuste (L.), southern white Native Rare Foliage

Colias eurytheme Boisduval, alfalfa caterpillar Native Rare Foliage

Pieris napi (L.), mustard white Native Rare Foliage

Pieris rapae (L.), imported cabbageworm Invader Europe 1850-1900 Frequent Foliage

Pontia protodice (Boisduval & LeConte), Native Rare Fruit, foliage

southern cabbageworm

Family Pterophoridae - plume moths

Platyptilia carduidactyla (Riley), Native Frequent Blossom,

artichoke plume moth fruit, stem/

vine, foliage

Family Pyralidae - borers, budworms, leaftiers,

webworms, and snout moths

Achyra rantalis (Guenée), garden webworm Native Rare Foliage

Crambus and others, sod and root webworms Native Rare Stem/vine,

foliage,

root/seed/

bulb

Diaphania hyalinata (L.), melonworm Native Periodic Fruit, foliage

Diaphania nitidalis (Stoll), pickleworm Native Frequent Blossom,

fruit

Diatraea crambidoides (Grote), Native Stem/vine,

southern cornstalk borer foliage

Diatraea grandiosella Dyar, southern corn borer Invader Central America, 1850-1900 Rare Fruit, stem/

Mexico, Caribbean vine, foliage

Diatraea saccharalis (F.), sugarcane borer Invader Central America, 1850-1900 Rare Fruit, stem/

Mexico, Caribbean vine, foliage

Elasmopalpus lignosellus (Zeller), Native Rare stem/vine

lesser cornstalk borer

Etiella zinckenella (Treitschke), limabean pod borer Invader ? 1850-1900 Rare Fruit

Evergestis pallidata (Hufnagel), Invader Europe 1850-1900 Rare Stem/vine,

purplebacked cabbageworm foliage, Root/

seed/bulb

Evergestis rimosalis (Guenée), Native Periodic Foliage

Hellula phidilealis (Walker), cabbage budworm Invader? Central America, ? Rare Stem/vine

cross-striped cabbageworm Mexico, Caribbean

Hellula rogatalis (Hulst), cabbage webworm Native Rare Foliage

Hellula undalis (F.), oriental cabbage webworm Invader? ? ? Rare Foliage

Herpetogramma bipunctalis (F.), ? Rare Foliage

southern beet webworm

Hymenia perspectalis (Hübner), ? Rare Foliage

spotted beet webworm

Loxostege cereralis (Zeller), alfalfa webworm Native Rare Foliage

Loxostege sticticalis (L.), beet webworm Invader Europe ? Rare Foliage

Omphisa anastomosalis (Guenée), Invader Asia 1850-1900 Rare Stem/vine,

sweetpotato vine borer tuber

Ostrinia nubilalis (Hübner), European corn borer Invader Europe 1900-1950 Frequent Blossom,

fruit, stem/

Status Origin Host Period of Damage Site

range detection frequency damaged

Appendix continued

38 AMERICAN ENTOMOLOGIST • Spring 2002

vine, foliage

Plutella xylostella (L.), diamondback moth Invader Europe 1850-1900 Frequent Foliage

Spoladea recurvalis (F.), Hawaiian beet webworm Invader ? ? Rare Foliage

Udea profundalis (Packard), false celery leaftier Native Rare Stem/vine,

foliage

Udea rubigalis (Guenée), celery leaftier Native Rare Stem/vine,

foliage

Family Sesiidae - vine borers and clearwing moths

Melittia calabaza Duckworth & Eichlin, Rare Stem/vine

southwestern squash vine borer Native

Melittia cucurbitae (Harris), squash vine borer Native Frequent Stem/vine

Family Sphingidae - hornworms and sphinx moths

Agrius cingulatus (F.), sweetpotato hornworm Native Rare Foliage

Hyles lineata (F.), whitelined sphinx Native Rare Foliage

Manduca quinquemaculata (Haworth), Native Periodic Fruit, foliage

tomato hornworm

Manduca sexta (L.), tobacco hornworm Native Periodic Fruit, foliage

Family Tortricidae - leafroller moths

Cydia nigricana (F.), pea moth Invader Europe 1850-1900 Rare Fruit

Order Orthoptera - Grasshoppers and Crickets

Family Acrididae - grasshoppers

Melanoplus bivittatus (Say), Native Periodic Foliage

twostriped grasshopper

Melanoplus differentialis (Thomas), Native Periodic Foliage

differential grasshopper

Melanoplus femurrubrum (De Geer), Native Rare Foliage

redlegged grasshopper

Melanoplus propinquus Scudder, Native Rare Foliage

southern redlegged grasshopper

Melanoplus sanguinipes (F.), migratory grasshopper Native Periodic Foliage

Romalea microptera (Beauvois), Native Periodic Foliage

eastern lubber grasshopper

Schistocerca americana (Drury), Native Rare Foliage

American grasshopper

Family Gryllidae - field crickets

Gryllus pennsylvanicus Burmeister, fall field cricket Native Rare Blossom, fruit,

stem/vine,

foliage, root/

seed/bulb

Gryllus rubens Scudder, southeastern field cricket Native Rare Blossom, fruit,

stem/vine,

foliage,

root/seed/

bulb

Gryllus veletis (Alexander & Bigelow), Native Rare Blossom,

spring field cricket fruit, stem/

vine, foliage,

root/seed/

bulb

Family Gryllotalpidae - mole crickets

Scapteriscus abbreviatus Scudder, Invader South America 1850-1900 Rare Stem/vine,

shortwinged mole cricket foliage, tuber,

root/seed/

bulb

Scapteriscus borellii Giglio-Tos, southern mole cricket Invader South America 1850-1900 Rare Stem/vine,

foliage,

tuber, root/

seed/bulb

Scapteriscus vicinus Scudder, tawny mole cricket Invader South America 1850-1900 Rare Stem/vine,

Appendix 1. (continued)

Status Origin Host Period of Damage Site

range detection frequency damaged

Order Lepidoptera - Caterpillars, Moths and Butterflies (continued)

AMERICAN ENTOMOLOGIST • Volume 48 Number 1 39

foliage,

tuber, root/

seed/bulb

Family Tettigoniidae - shield-backed crickets

Anabrus simplex Haldeman, Mormon cricket Native Rare Foliage

Peranabrus scabricollis (Thomas), coulee cricket Native Rare Foliage

Order Thysanoptera - Thrips

Anaphothrips obscurus (Müller), grass thrips Native Rare Foliage

Caliothrips fasciatus (Pergande), bean thrips Native Rare Foliage

Frankliniella fusca (Hinds), tobacco thrips Native Frequent Blossom,

foliage

Frankliniella occidentalis (Pergande), Native Frequent Blossom

western flower thrips

Thrips palmi Karny, melon thrips Invader Asia 1950-present Frequent Blossom, fruit,

foliage

Thrips tabaci Lindeman, onion thrips Invader Asia 1850-1900 Frequent Fruit, foliage

Other Invertebrate Pests

Class Acari - mites

Aculops lycopersici (Massee), tomato russet mite Invader ? 1800-1850 Periodic Stem/vine,

foliage

Oligonychus pratensis (Banks), Banks grass mite Native Rare Foliage

Polyphagotarsonemus latus (Banks), broad mite Invader Asia ? Periodic Blossom,

fruit, foliage

Rhizoglyphus echinopus (Fumouze & Robin), Invader ? ? Rare Root/seed/

bulb mite bulb

Rhizoglyphus robini Claparede, bulb mite Invader ? ? Rare Root/seed/

bulb

Tetranychus tumidus Banks, tumid spider mite Native Rare Foliage

Tetranychus turkestani Ugarov & Native Asia Rare Foliage

Nikolski, strawberry spider mite

Tetranychus urticae Koch, twospotted spider mite Invaver Europe 1850-1900 Frequent Foliage

Class Collembola - springtails

Bourletiella hortensis Fitch, garden springtail Invader Europe ? Rare Stem/vine,

foliage

Class Diplopoda - millipedes

Oxidus gracilis Koch, garden millipede Invader ? ? Rare Fruit, stem/

vine, tuber

Class Isopoda - pillbugs and sowbugs

Armadillidium vulgare (Latreille), common pillbug Invader Europe ? Rare Fruit, stem/

vine, foliage

Porcellio scaber Latreille, dooryard sowbug Invader Europe ? Rare Fruit, stem/

vine, foliage

Class Gastropoda - slugs and snails

Arionater rufus (L.), black slug Invader Europe 1850-1900 Rare Foliage

Cepaea, Helix, Rumina spp. and others, snails

Cepaea hortensis (Müller), white-lipped snail Invader Europe 1850-1900 Rare Foliage

Cepaea nemoralis (L.), brown-lipped snail Invader Europe 1850-1900 Rare Foliage

Deroceras, Limax, Milax spp. and others, slugs

Deroceras laeve (Müller), marsh slug Native Rare Foliage

Deroceras reticulatum (Müller), gray garden slug Invader Europe 1850-1900 Periodic Root/seed/

bulb

Helix aperta Born, singing snail Invader Europe 1850-1900 Rare Foliage

Helix aspera Müller, brown garden snail Invader Europe 1850-1900 Periodic Foliage

Helix pomatia L., Roman snail Invader Europe 1850-1900 Rare Foliage

Limax flavus (L.), tawny garden slug Invader Europe 1850-1900 Periodic Foliage

Limax maximus L., spotted garden slug Invader Europe 1850-1900 Periodic Foliage

Milax gagates (Draparnand), greenhouse slug Invader Europe 1850-1900 Periodic Foliage

Otala lactea (Müller), milk snail Invader Europe ? Rare Foliage

Rumina decollata (L.), decollate snail Invader Europe ? Rare Foliage

Theba pisana (Müller), white garden snail Invader Europe 1900-1950 Rare Foliage

Class Symphyla - symphylans

Scutigerella immaculata (Newport), Invader Europe ? Periodic Root/seed/

garden symphylan bulb

Status Origin Host Period of Damage Site

range detection frequency damaged

Order Orthoptera - Grasshoppers and Crickets (continued)

Host Range of Cotton Flea Beetle (Podagrica puncticollis) in a Hot Dry Tropical Environment of Ethiopia

Article

Full-text available

Jan 2019

Bayeh Mulatu Aregay

Cotton flea beetle, Podagrica puncticollis is the most destructive insect pest of cotton in northwestern part of Ethiopia. This study was conducted to identify and determine the host range of cotton flea beetle in Metema area. The field survey was undertaken from June 27, 2015 to January 9, 2016 in ten kebele administrations of the district. At least three fields were prospected after every 15 days, in each kebele for host plants as well as to determine population density and percent leaf damage by adult cotton flea beetle, at different growth stages of cotton plant. The composition of plant species with damaged symptom or infested by flea beetle was analysed using quantitative means and identified by comparing specimens with description of identification manuals. A total of 11 host plant species of cotton flea beetle were identified in the cotton growing areas of Metema throughout a season. Indigofera longibarbata (Fabaceae), Hibiscus articulatus, H. cannabinus, H. vitifolius, Abutilon figarianum, Sida alba and S. urens (Malvaceae), Bidens pilosa and B. setigera (Asteraceae), Corchorus olitorius and C. trilocularis (Tiliaceae) found to be common host plants of cotton flea beetle. Thus, among the host plants, H. vitifolius, H. cannabinus, H. articulatus, C. olitorius and C. trilocularis were the most suitable hosts for adult cotton flea beetle in respect of the number of adults per plant and percent foliage damage they sustained. These findings could aid in developing long-term management strategies for this important insect pest existing in a hot dry tropical environment of northwestern Ethiopia.

Grapevine plant defense responses associated with arthropod herbivory: A review

Article

Dec 2023
CROP PROT

Research on the morphological and molecular diagnosis of Hyalopterus pruni (Geoffroy)Hyalopterus pruni (Geoffroy)'nin morfolojik ve moleküler teşhisi üzerine araştırma

Article

Aug 2023

Aphids are one of the most important groups of insects that cause damage to agricultural crops, ornamental plants, as well as herbaceous and woody plants in their natural habitats. Aphids that feed on plant sap can cause significant crop losses worldwide, ranging from 70% to 80%, due to stunted growth, deformation, wilting, and other detrimental effects on plants. Despite the chemical, biological, and integrated pest management methods applied against these damages, aphids have rapidly expanded their distribution areas and their damages have been increasing in recent times. Hyalopterus Koch (Hemiptera: Aphididae), a genus of aphids, are known worldwide as pests that infest Prunus trees, which are stone fruit trees. They cause damage by feeding on the trees and also by transmitting plant viruses. Subsequently, improper and indiscriminate use of chemical control methods negatively impacts both human and environmental health. Accurate identification of aphids, especially in terms of invasive species, is crucial for early detection of their damages in the initial stages. The mitochondrial cytochrome c oxidase subunit I (COI) gene is an effective gene region used in the identification of many economically important plant pests worldwide. In this study, a total of 50 individuals of Hyalopterus pruni (Geoffroy) were collected from three localities Şarköy (Ulaman, Bulgurlu, Gölcük, Cumhuriyet, Mürefte, Hoşköy, Gaziköy, Tepeköy, Palamut), Süleymanpaşa (Yüzüncüyıl, Altınova, Banarlı, Barboros, Bıyıkali, Çınarlı, Değirmenaltı, Ferhadanlı, Hürriyet, Karacakılavuz, Karaevli, Naip, Namık Kemal and Marmaraereğlisi (Bahçelievler, Cedit Ali Paşa, Dereağzı, Mustafa Kemal Paşa, Sultanköy, Türkmenli, Yakuplu and Yeniçiftlik) in Tekirdağ province. The species H11, H41, and H61, which were selected to represent three counties, were sequenced, and the molecular sequence results revealed that H. pruni, as morphologically described, showed 99% consistency at the molecular level.

Rapid Identification of Aphid Species by Headspace GC-MS and Discriminant Analysis

Article

Full-text available

Jun 2023

Aphids are a ubiquitous group of pests in agriculture that cause serious losses. For sustainable aphid identification, it is necessary to develop a precise and fast aphid identification tool. A new simple chemotaxonomy approach to rapidly identify aphids was implemented. The method was calibrated in comparison to the established phylogenetic analysis. For chemotaxonomic analysis, aphids were crushed, their headspace compounds were collected through closed-loop stripping (CLS) and analysed using gas chromatography—mass spectrometry (GC-MS). GC-MS data were then subjected to a discriminant analysis using CAP12.exe software, which identified key biomarkers that distinguish aphid species. A dichotomous key taking into account the presence and absence of a set of species-specific biomarkers was derived from the discriminant analysis which enabled rapid and reliable identification of aphid species. As the method overcomes the limits of morphological identification, it works with aphids at all life stages and in both genders. Thus, our method enables entomologists to assign aphids to growth stages and identify the life history of the investigated aphids, i.e., the food plant(s) they fed on. Our experiments clearly showed that the method could be used as a software to automatically identify aphids.

Identification and Reconsidering Phylogeny of Some Aphid Species, (Hemiptera: Aphididae), Based on Molecular DNA Markers Using ISSRs-PCR Technique

Article

Dec 2021

Host Range of Cotton Flea Beetle (Podagrica puncticollis) in a Hot Dry Tropical Environment of Ethiopia

Article

Full-text available

Jan 2019

Mulatu Wakgari

Pest categorisation of Exomala orientalis

Article

Full-text available

Apr 2020

Abstract The EFSA Panel on Plant Health performed a pest categorisation of Exomala orientalis (Coleoptera: Rutelidae) (Oriental beetle) for the EU. Larvae feed on the roots of a variety of hosts including most grasses and many vegetable crops. Maize, pineapples, sugarcane are among the main host plants. Larvae are particularly damaging to turfgrass and golf courses. The adults feed on flowers and other soft plant tissues (e.g. Alcea rosea, Dahlia, Iris, Phlox and Rosa). Eggs are laid in the soil. Larvae feed on host roots and overwinter in the soil. Adults emerge from pupae in the soil in May‐June and are present for about 2 months. E. orientalis usually completes its life cycle in 1 year although individuals can spend two winters as larvae. Commission Implementing Regulation (EU) 2019/2072 (Annex IIA) regulates E. orientalis. The legislation also regulates the import of soil attached to plants for planting from third countries; therefore, entry of E. orientalis eggs, larvae and pupae is prevented. E. orientalis is native to Japan or the Philippine islands. It is also found in East Asia and India, Hawaii and north‐eastern USA. It is assumed to have reached USA via infested nursery stock. Plants for planting (excluding seeds) and cut flowers provide potential pathways for entry into the EU. E. orientalis has been intercepted only once in the EU, on Ilex crenata bonsai. Climatic conditions and the availability of host plants provide conditions to support establishment in the EU. Impacts on maize, grassland and turfgrass would be possible. There is uncertainty on the extent of the impact on host plants which are widely commercially grown (e.g. maize) Phytosanitary measures are available to reduce the likelihood of entry. E. orientalis satisfies the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest. Of the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union regulated non‐quarantine pest, E. orientalis does not meet the criterion of occurring in the EU.

Organic farming to mitigate biotic stresses under climate change scenario

Article

Full-text available

Jul 2024

Background Climate change is inevitable owing from modern-day chemical agriculture, exerting detrimental impacts on sustainable crop production. Global agriculture is now facing serious threats from biotic stresses like weeds, pests, diseases, etc. These stresses not only hamper growth and production but also reduce crop quality. Main body of the abstract Exclusive reliance on synthetic inputs to tackle biotic stresses has created resistance, resurgence, residues, etc., leading to environmental pollution. Although plants adopt defensive mechansims, such biotic stresses need to be addressed properly with various eco-friendly organic farming approaches. Suitable modification and adoption of various organic agronomic practices (manual, mechanical, cultural, and biological) such as soil solarization, crop rotation, intercropping, tillage, sowing time and method, nutrient, water and intercultural operations, organic formulations, selection of resistant/tolerant varieties, etc., can mitigate the negative impacts of biotic stresses to a high extent resulting in uplift in crop production as well as the quality of produce. Microorganisms not only alter soil health positively for high crop production but also alleviate biotic stresses through bio-stimulant properties. Various indigenous technical knowledge approaches show great promise to tackle biotic stresses further. Short conclusion Adequate research, integration of multiple technologies, build-up of awareness, etc., are the keys for successful organic plant protection under changing climate scenario.

The role of structural variants in pest adaptation and genome evolution of the Colorado potato beetle, Leptinotarsa decemlineata (Say)

Article

Jan 2023

Structural variation has been associated with genetic diversity and adaptation. Despite these observations, it is not clear what their relative importance is for evolution, especially in rapidly adapting species. Here we examine the significance of structural polymorphisms in pesticide resistance evolution of the agricultural super‐pest, the Colorado potato beetle, Leptinotarsa decemlineata. By employing a parent offspring trio sequencing procedure, we develop highly contiguous reference genomes to characterize structural variation. These updated assemblies represent >100‐fold improvement of contiguity and include derived pest and ancestral non‐pest individuals. We identify >200,000 structural variations, which appear to be non‐randomly distributed across the genome as they co‐occur with transposable elements and genes. Structural variations intersect with exons in a large proportion of gene annotations (~20%) that are associated with insecticide resistance (including cytochrome P450s), development, and transcription. To understand the role structural variations play in adaptation, we measure their allele frequencies among an additional 57 individuals using whole genome resequencing data, which represents pest and non‐pest populations of North America. Incorporating multiple independent tests to detect the signature of natural selection using SNP data, we identify 14 genes that are likely under positive selection, include structural variations, and SNPs of elevated frequency within the pest lineages. Among these, three are associated with insecticide resistance based on previous research. One of these genes, CYP4g15, is co‐induced during insecticide exposure with glycosyltransferase‐13, which is a duplicated gene enclosed within a structural variant adjacent to the CYP4g15 genic region. These results demonstrate the significance of structural variations as a genomic feature to describe species history, genetic diversity, and adaptation.

Economic Determinants of Invasion and Discovery of Nonindigenous Insects

Article

Full-text available

Apr 2008

Introductions of nonindigenous organisms into the United States have been linked to international trade. The individual contributions of imports, immigration, and international travel, however, are poorly understood because introduction dates are unavailable. We examine relationships between economic trends and discoveries of nonindegenous insects and use these relationships to infer the timing and determinants of introductions. We find that a few variables can explain much variation in species introductions and identifications. The most significant contributor to the introduction appears to be agricultural imports. Currently available proxies for academic effort are weak determinants of the probability that introduced species are identified.

The immigration of insects to Florida, with a tabulation of records published since 1970

Article

Full-text available

Mar 1992
FLA ENTOMOL

A table is presented of the recent (published since 1970) records of presence of exotic insects in Florida. The table includes 271 species, 209 of which were first collected in Florida after 1970. We assume that these insects are immigrants, and we calculated mean rates of 7.7 and 12.0 immigrations per year in the 1970s and 1980s, respectively. We judge that about 20 recent immigrants are, or could become, major pests in Florida. At least 8% of the species appear to have arrived as stowaways, and many of the actual or potential major pests are among them. Immigrant species are not equitably distributed among orders or among families within orders. Species in the orders Lepidoptera and Coleoptera are especially well-represented. By far the largest proportion of recent insect immigrants to Florida comes from the Neotropical region. Our results suggest further information that is needed to answer questions about the invasibility of Florida.

Strangers in paradise: impact and management of non-indigenous species in Florida

Article

Jan 1997

Exotic invertebrates and their effects on California

Article

Jan 1989

The Faunal Connections Between Europe and North America

Article

Nov 1957

Foreign exploration and importation of natural enemies

Article

Dec 1976

History of Insect Introductions

Chapter

Dec 1983

REECE I. SAILER

The biogeography of herbivorous arthropods: species accrual on tropical crops.

Article

Jan 1983

The size of range of host plants and animals is the best single correlate of number of associated parasite species. For a single species of host distributed over many regions, there should exist 2 important additional correlates: the sizes of source pools of potential colonists within regions and the distribution of the host's close relatives among regions. A comparison of the data for the herbivorous arthropods of cacao, citrus, coconuts, coffee, cotton, rice and sugar cane shows that regions in Amazonia, Southern Asia/Australia and sub-Saharan Africa consistently fall above species-area regression lines, whereas regions in North and South America (except Amazonia), Western Asia and Europe tend to fall below them. The pattern implicates the importance of source pool size of potential colonists and taxonomic isolation of the host in influencing arthropod accrual. -from Authors

Evolution of Insect Pests. Patterns of Variation

Article

Sep 1993

Species-Area Relationships of Insects on Host Plants: Herbivores on Rosebay Willowherb

Article

Feb 1982

Malcolm MacGarvin

(1) The species-area relationship for phytophagous insect species feeding on rosebay willowherb (Fireweed), Chamerion angustifolium (L.) J. Holub was studied during 1979 and 1980. Three aspects were examined. (a) The number of species and individual insects present on patches ranging in size from 0.25 m2 to 7050 m2, at sites within Great Britain. (b) The detailed mapping of the distribution of three species within a 28 X 20 m patch of rosebay. (c) The colonization of new, transplanted patches of rosebay over a 2-year period. (2) There was a shallow, but significant regression of species numbers on patch size, the slope of which was virtually identical for both years. The height of plants (a measure of habitat heterogeneity) did not significantly increase the variation explained by the regression. (3) The number of species, and the total number of individuals, per plant also increased with patch size. (4) The abundance of individual species per plant was either positively related to patch size, had no correlation or, for one species, was negatively related. (5) There was no clear relationship between species diversity and patch size. (6) For the majority of species, the variance to mean ratio of individuals per plant within patches increased with increasing population size. For those species whose abundance was related to patch size, this implies that the distributions became more aggregated with increasing patch size. (7) The three species whose distributions were mapped within a patch all had aggregated distributions of numbers per plant, and between different regions of the patch. (8) The colonization of new patches was rapid. Mompha raschkiella had attained densities comparable to those observed naturally within one season, as did two other species sampled during the second year. (9) Habitat heterogeneity is probably not an important aspect of the species-area relationship nor can passive sampling be evoked in isolation from other factors. Instead it is thought that passive sampling, `active sampling' (Root's resource concentration hypothesis) and area-dependent extinction all play a part in generating the species-area relationship, the contribution of each varying from species to species.

Evolution of the Richness-Area Correlation for Cynipid Gall Wasps on Oak Trees: A Comparison of Two Geographic Areas

Article

Mar 1979

Substantial evidence indicates that host geographic range is the most important determinant of the number of herbivorous and carnivorous parasite species associated with that host. Thus far, the reasons for this pattern have not emerged because: 1) Extinction rates of parasites on hosts have not yet been measured, consequently the observed species-area relationships cannot be interpreted in terms of the premises of island biogeography theory. 2) Low correlations between species richness and geographic range have not been documented and interpreted. These cases are necessary to clarify other potential influences on parasite species richness. Here we treat the second of these with an analysis of host relations in a guild of gallforming cynipine wasps which parasitize oak trees. Two geographic regions sharing no Cynipinae or oak species are analyzed for species-area patterns via linear regression. In the Atlantic region, 378 cynipine species attacking 26 Quercus conformed to the equation log S = 0.25 log A + 0.12, r2 = 0.41, whereas in California 159 Cynipinae attacking 11 Quercus conformed to log S = 0.72 log A - 1.52, r2 = 0.72. The higher z-value in California may be due to the greater topographic diversity, oak varietal diversity, and altitudinal variation characteristic of this region. The higher coefficient of determination probably results from smaller latitudinal variation in climate coupled with broader geographic overlap of oaks than in the Atlantic region. Evidence suggests that host shifting is unimportant in the Cynipinae. Instead, Cynipinae speciate parapatrically on the same host oak and radiation proceeds in parallel with oak radiation. Geographic overlap of host oaks, therefore, has little effect on colonization rates.

North American Vegetable Pests: The Pattern of Invasion

Figures

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