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Repellent activity of citrus oils against the cockroaches Blattella germanica, Periplaneta americana and P. fuliginosa

June 2009
Journal of Pesticide Science 34(2):77-88

Authors:

The repellent efficacy of 17 essential oils against the German cockroach, Blattella germanica was examined using a T-tube olfactometer. Five oils repelled B. germanica with good efficacy, ranging from 70.0 to 96.7%. Four of these oils, grapefruit, lemon, lime, and orange, were from the citrus family Rutaceae. These citrus essential oils showed similar repellent activity against two more cockroach species, such as Periplaneta americana and P. fuliginosa. Gas chromatography (GC) and GC-mass spectrometry analyses revealed that the major components responsible for the repellent activity of the citrus oils were limonene, β-pinene and γ-terpinene. Limonene appears to be the main component responsible for the repellent activity rather than β-pinene and γ-terpinene. The repellent efficacy of these components varied with different doses and the cockroach species tested. It is likely that minor components of the oils also contributed to the overall repellent activity of citrus essential oils, except orange oil. The activity of orange oil is almost solely attributed to the activity of limonene. Also, the repellent activity of citrus oil and that of each of the terpenoids makes little difference to the efficacy of a repellant against the three species of cockroaches.

Names and sources of seventeen essential oils used in this study

…

Olfactory response of Blattella germanica to the seventeen essential oils a)

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Olfactory response of Periplaneta americana and P. fuliginosa to the four essential oils

…

Ratios of major components of five Citrus oils identified by GC and GC/MS

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Repellency of major components of four Citrus oils against female adults of B. germanica in T-tube olfactometer

…

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J. Pestic. Sci., 34(2), 77–88 (2009)

DOI: 10.1584/jpestics.G07-30

Cockroaches are insects with worldwide distribution that

thrive best in warm, humid, lowland areas throughout the

Tropics. Of the 4000 species of cockroaches (Dictyoptera:

Blattodea) known to exist, approximately 30 species coexist

in human habitats and approximately 16 species are associ-

ated with human health problems.1) The cockroach species

that are closely associated with human dwellings, food-pro-

cessing industries, service-rendering facilities and/or occupa-

tional environments include Blattella germanica, Blatta ori-

entalis, Periplaneta australasiae (Fabricius), P. americana

(Linnaeus) and Supella supellectilium (Serville).2) Among

these, B. germanica is the most ubiquitous and also the one

most frequently seen in food preparation areas, restaurants,

cafeterias, kitchens and toilets. The prevalence of B. german-

ica in human habitats makes this type of cockroach a major

nuisance and mechanical transmitter of etiological disease

agents.3)

Cockroaches have long been recognized as potential me-

chanical vectors of human intestinal parasites and animal

pathogens, as well as sources of human allergens. Indeed, it

has been found that cockroach antigen is the most common

asthma-inducing allergen in children in inner cities.4,5) Cock-

roaches are controlled primarily with synthetic organic insec-

ticides in the form of baits, aerosols, foggers, and crack treat-

ments.6,7) At present, chemical-based methods for cockroach

management generally involve repeated applications of resid-

ual insecticides (e.g., dichlorvos, chlorpyrifos, propoxur, and

pyrethroids),8) stomach poisons (e.g., hydramethylnon, boric

acid, and sulﬂuramid),9) and insect growth regulators (e.g.,

noviﬂumuron and lufenuron).10,11) However; several factors

have limited the use of synthetic chemicals: the development

of natural resistance by cockroaches, and negative effects on

the environment and human health in some cases. Conse-

quently, an intensive effort has been made to ﬁnd alternative

repellents, which are environmentally friend and ecologically

safe.12,13)

Many natural compounds isolated from plants have demon-

strated a wide spectrum of biological activities. Among these

various kinds of natural substances that have received particu-

Repellent activity of citrus oils against the cockroaches Blattella

germanica, Periplaneta americana and P. fuliginosa

Changmann YOON, Shin-Ho KANG, Jeong-Oh YANG, Doo-Jin NOH,

Pandiyan INDIRAGANDHI and Gil-Hah KIM*

Department of Plant Medicine, Chungbuk National University, Cheongju 361–763,

Republic of Korea

(Received September 10, 2007; Accepted December 24, 2008)

The repellent efﬁcacy of 17 essential oils against the German cockroach, Blattella germanica was examined

using a T-tube olfactometer. Five oils repelled B. germanica with good efﬁcacy, ranging from 70.0 to 96.7%.

Four of these oils, grapefruit, lemon, lime, and orange, were from the citrus family Rutaceae. These citrus essen-

tial oils showed similar repellent activity against two more cockroach species, such as Periplaneta americana and

P. fuliginosa. Gas chromatography (GC) and GC-mass spectrometry analyses revealed that the major components

responsible for the repellent activity of the citrus oils were limonene,

-pinene and

-terpinene. Limonene ap-

pears to be the main component responsible for the repellent activity rather than

-pinene and

-terpinene. The

repellent efﬁcacy of these components varied with different doses and the cockroach species tested. It is likely

that minor components of the oils also contributed to the overall repellent activity of citrus essential oils, except

orange oil. The activity of orange oil is almost solely attributed to the activity of limonene. Also, the repellent ac-

tivity of citrus oil and that of each of the terpenoids makes little difference to the efﬁcacy of a repellant against

the three species of cockroaches. © Pesticide Science Society of Japan

Keywords:cockroach, repellent, citrus oils, monoterpene, limonene.

*To whom correspondence should be addressed.

E-mail: khkim@chungbuk.ac.kr.

Published online April 28, 2009

©Pesticide Science Society of Japan

Original Article

lar attention as natural agents for insect management are es-

sential oils from aromatic and medicinal plants.12–15) Numer-

ous plants and derivative products, in particular essential oils,

have been investigated and described as potentially natural

sources of insect repellent.11,16) Insect repellents are sub-

stances that act locally or at a distance, deterring an insect

from ﬂying to, landing on or biting human or animal skin. Al-

though the use of synthetic repellents tends to be more effec-

tive than natural repellents, the development of insect resist-

ance has restricted the usefulness of synthetic repellents.17)

Thus, plant-based repellents may be comparable to, or even

somewhat better than, synthetics, depending on the formula.

Many plant essential oils and their components have been

shown to have good repellent activity,18–20) for example, Piper

guineense (black pepper) seed oil exhibits both insecticidal

and repellent activity against the stored product insect pests.18)

Benzene derivatives and terpenoids have also been reported to

have insecticidal and repellent activities against Periplanata

americana.19) In addition, most plant-based insect repellents

currently on the market contain essential oils from one or

more of the following plants: citronella (Cymbopogon nar-

dus), cedar (Juniper virginiana), eucalyptus (Eucalyptus mac-

ulata), geranium (Pelargonium reniforme), lemon-grass

(Cymbopogon excavatus), peppermint (Mentha piperita),

neem (Azadirachta indica) and soybean (Neonotonia

wightii).20)

Citrus oils, such as grapefruit, lemon, lime and orange, are

widely utilized in various industries, including agriculture and

household cleaning. Their constituents have been extensively

studied and used for various applications; however, it has not

been properly addressed whether the monoterpenes in citrus

oils can act as insect repellents or whether they could be used

in agriculture to replace synthetic insecticides. To test this, we

examined the repellent activity of 17 essential oils, including

ﬁve citrus oils, against household insect pest cockroaches,

with special reference to three different species. The major

active components of the oils found to have repellent effects

were detected by gas chromatography (GC) and GC-mass

Spectrometry (MS), and then also tested for their repellent ac-

tivity.

Materials and Methods

1. Essential oils and terpenes

The names and sources of the seventeen essential oils used in

this study are listed in Table 1. Myrrh, pine needle oil and

strawberry oil were from Charabot, France, while the others

were purchased from JinArome Co., USA. The terpene com-

pounds used in this study were as follows:

-myrcene (90%)

(Sigma, St. Louis, MO),

-pinene (98%),

-pinene (97%),

terpinene (97%), and d-limonene (97%) (Aldrich, Milwaukee,

WI). Benzene (99%) was purchased from Aldrich.

2. Test insects

Three species of cockroach, the German cockroach Blat-

tella germanica, the American cockroach Periplaneta ameri-

cana, and the smokybrown cockroach P. fuliginosa, were ini-

tially obtained from the Korean Research Institute of Chemi-

cal Technology and then reared in our laboratory for 8 years

without exposure to any known insecticides. They were fed

on mouse food pellets and water and were kept in cages

78 C. Yoon et al. Journal of Pesticide Science

Tab le 1 . Names and sources of seventeen essential oils used in this study

Common name Scientiﬁc name Family Source

Caraway seed Carum carvi Umbelliferae JinArome (USA)

Clary sage Salvia sclarea Labiatae JinArome (USA)

Clove leaf Eugenia caryophyllata Oleaceae JinArome (USA)

Coriander Coriandrum sativum Umbelliferae JinArome (USA)

Eucalyptus Eucalyptus globulus Myrtaceae JinArome (USA)

Grapefruit Citrus paradisi Rutaceae JinArome (USA)

Lemon Citrus limonum Rutaceae JinArome (USA)

Lime Citrus aurantifolia Rutaceae JinArome (USA)

Marjoram Origanum vulgare Labiatae JinArome (USA)

Myrrh Commiphora myrrh Burseraceae Charabot (France)

Orange Citrus sinensis Rutaceae JinArome (USA)

Petitgrain Citrus aurantium Rutaceae JinArome (USA)

Pine needle Pinus sylvestris Pinaceae Charabot (France)

Rosemary Rosmarinus ofﬁcinalis Labiatae JinArome (USA)

Spearmint Mentha spicata Labiatae JinArome (USA)

Strawberry Fragaria ananassa Rosaceae Charabot (France)

Ylangylang Cananga odorata Annonaceae JinArome (USA)

(32.028.022.5 cm) at 253°C and 60% RH with a pho-

toperiod of 12 : 12 (L : D) h. For the repellency test, we used

10–20d-old adult female cockroaches since they showed the

highest activity to chemicals. To avoid the effects of anesthe-

sia or physical stress that may be caused by handling the

cockroaches with tweezers, the insects and their shelters were

transferred to repellent test cages by shaking. The number of

insects was then adjusted by removing extra insects from the

test cage with tweezers.

3. Gas chromatography-mass spectroscopy analysis of

essential oils

The citrus oils (grapefruit, lemon, lime, orange and petit-

grain) were analyzed by gas chromatography (GC, Agilent

Technology 6890N) and gas chromatography-mass spectrom-

etry (GC/MS, Hewlett Packard 7890A/5975C) equipped with

a splitless injector. GC analysis was performed using columns

of DB-WAX (0.25 mm I.D.30m length) and DB-1 (0.25

mm I.D.30m length), and nitrogen (N2) as the carrier gas at

a ﬂow rate of 1.0 ml/min. The temperature conditions were as

follows: initial temperature of 30°C, ramped at 2°C/min to

180°C for 60 min, while the injector and detector were main-

tained at 200°C and 210°C, respectively. Spectra were ob-

tained at 70 eV. The components of the oils were identiﬁed by

comparing their mass spectra to those of authentic samples in

a mass spectra library (The Wiley Registry of Mass Spectral

Data).

4. Repellent bioassays

The ability of 17 essential oils to repel B. germanica was

tested using a T-tube olfactometer (ID 9 cm; stem 15 cm; arm

length 22 cm; angle between arms 180°) made in our labora-

tory. Slightly pressurized air that was ﬁltered by charcoal and

silica gel before entering the sample container was introduced

into the ﬂight chamber through the two tube arms of the T-

tube olfactometer at a ﬂow rate of 100 ml/min. A ﬁlter paper

treated with 10 or 1

l of essential oils or a monoterpene at

the amount found in the various citrus oils was placed in the

treated (T) side while the untreated (U) side remained empty.

Thus, in this device, the cockroach is offered two choices, i.e.,

moving towards the smell or moving away from it. Some of

the cockroaches stayed before the T-junction, or in another

ambiguous region, and they were counted as no-choice. Each

oil and compound was tested with forty cockroaches. The ex-

periments were conducted in the dark (to avoid the effect of

light) in rooms maintained at 283°C with 6010% RH. The

response of an insect was evaluated by recording the chamber

in which the insect stayed after 5min. Oils that effectively re-

pelled B. germanica were also tested with the other two cock-

roaches, i.e., P. americana and P. fuliginosa. GC and GC/MS

analyzed the major components of each essential oil; the

major components were then bioassayed at the amounts pres-

ent in the various citrus oils. The preference ratios in the

bioassays were compared using the binominal sign test.21)

Results and Discussion

1. Repellency of essential oils

When cockroaches were used in a blank test with the T-tube

olfactometer, there was no difference in their choice of arm,

which indicates that the olfactometer did not have any bias.

When screening the seventeen selected essential oils, only ﬁve

oils showed signiﬁcant repellent activity in the order of grape-

fruit (96.7%), lemon (92.9%), lime (86.7%), orange (71.4%)

and clove leaf (70.0%) against B. germanica at 10

l (Table

2). Based on the signiﬁcant repellent activity, except clove oil,

the four essential oils from the citrus group were chosen for

further experiments with B. germanica. Although petitgrain is

also a citrus oil, it did not show signiﬁcant activity; ylangy-

lang was attractive rather than repellent. Citrus oils at 10

repelled B. germanica adults more signiﬁcantly than that of

l, indicating the dose-dependant effect of essential oil to-

wards the pest insect species.

We subjected the citrus oils that repelled B. germanica to

further tests and found that at 10

l they also signiﬁcantly re-

pelled P. americana and P. fuliginosa (Table 3). Grapefruit oil

was the most effective repellent of all the oils tested against

the three different species of cockroaches with repellent activ-

ity of 96.7, 90.3, and 82.4% for B. germanica, P. americana

and P. fuliginosa, respectively. The lemon and lime oils re-

pelled P. americana (85.7 and 83.3%, respectively) slightly

less effectively than they repelled B. germanica (92.9 and

86.7%, respectively), and were even less effective against P.

fuliginosa (72.0 and 70.6%, respectively). While orange oil

mildly repelled P. americana (70.0%, similar to its effect on

B. germanica), its effect against P. fuliginosa was not signiﬁ-

cant (62.5%). Indeed, all the citrus oils tested repelled B. ger-

manica and P. americana better than P. fuliginosa. Of these

three kinds of cockroaches, it has been shown that P. fuligi-

nosa is relatively tolerant to low temperatures,22) which could

be linked to the observed difference in repellent activity. This

difference could of course be due to other different physiolog-

ical/biochemical characteristics.11)

Essential oils have been utilized as insecticides, an-

tifeedants, and repellents with a wide variety of target in-

sects12–19,23–27); however, one study that tested 96 herb extracts

found that while Japanese mint oil had a strong repellent ef-

fect against B. germanica, the essential oils of grapefruit,

lemon, and lime did not show strong repellent activity.28) This

is in contrast with our results, but the previous study was per-

formed by a classical assay method based on the behavior of

cockroach groups, and this may have been affected by the

chemical factors associated with aggregation. By contrast, we

used a T-tube olfactometer, in which the cockroaches had to

move either toward or away from the test oil, and therefore,

our method could detect the intrinsic activity of essential oils.

The T-tube olfactometer may have contributed to the unex-

pectedly large number of no-choices. We judged the result as

no-choice when the cockroaches stayed in the T-junction or in

Vol. 34, No. 2, 77–88 (2009) Repellent efﬁcacy of Citrus oils against cockroaches 79

a marginal region by dividing three equal regions between

arms. Although we optimized the conditions based on the pre-

liminary examinations, we could not reduce the numbers of

no-choice. It could be possible that some of the cockroaches

became insensible to effects of the tested oils after having

been exposed to them for 5 minutes under dark conditions.

Plant essential oils as cockroach repellents have been stud-

ied less than possible attractants and insecticides. Our obser-

vation of the repellent activity of citrus oils against three

species of cockroach suggests that citrus oils may serve as an

effective component in a commercial repellent against house-

hold insect pests like cockroaches.

2. Gas chromatography/mass spectroscopy analysis of

essential oils

The components of the four effective citrus oil repellents and

80 C. Yoon et al. Journal of Pesticide Science

Tab le 2 . Olfactory response of Blattella germanica to the seventeen essential oilsa)

Dose Olfactory response

Essential oils % P

(

l/ﬁlter Treated Untreated No

paper) Side (T) Side (U) choice

Caraway seed 10 10 15 15 60.0 n.s.

115111442.3 n.s.

Clary sage 10 13 15 12 53.6 n.s.

111151457.7 n.s.

Clove leaf 10 9 21 10 70.0 0.04

111181162.1 n.s.

Coriander 10 18 9 13 33.3 n.s.

113101743.5 n.s.

Eucalyptus 10 16 14 10 46.7 n.s.

115121344.4 n.s.

Grapefruit 10 1 29 10 96.7 0.0001

11023769.7 0.05

Lemon 10 2 26 12 92.9 0.0001

1821 11 72.4 0.05

Lime 10 4 26 10 86.7 0.0001

11223565.7 0.05

Marjoram 10 15 10 15 40.0 n.s.

114917 39.1 n.s.

Myrrh 10 12 15 13 55.5 n.s.

115131246.4 n.s.

Orange 10 8 20 12 71.4 0.04

110181264.3 n.s.

Petitgrain 10 17 10 13 37.0 n.s.

114151151.7 n.s.

Pine needle 10 16 11 13 40.7 n.s.

110171363.0 n.s.

Rosemary 10 11 17 12 60.7 n.s.

11915644.1 n.s.

Spearmint 10 9 16 15 64.0 n.s.

112181060.0 n.s.

Strawberry 10 16 11 13 40.7 n.s.

114131348.1 n.s.

Ylangylang 10 19 7 14 26.9 0.03

114151151.7 n.s.

a)n.s.: not signiﬁcant

the non-repellent citrus oils (petitgrain) were analyzed by GC

and GC/MS (Table 4). The major components were found to

be limonene,

-pinene,

-myrcene,

-terpinene,

benzene, linalool and linalyl acetate, but the proportion of

each component varied with respect to the different oils. The

most abundant monoterpene in all citrus oils was limonene,

which was found to be 93.8, 92.4, 61.3, 47.7, and 2.5% from

the orange, grapefruit, lemon, lime, and petitgrain oils, re-

spectively. Petitgrain had very low amounts of limonene and

did not contain

-myrcene or benzene; instead, it had large

amounts of linalool and linalyl acetate, which were absent

from the other oils. This may explain why petitgrain lacks sig-

niﬁcant repellant activity, unlike the other citrus oils (Table

2); petitgrain was thus excluded from further study. Unlike

the most effective repellent citrus oils, orange oil lacks

pinene,

-terpinene and benzene; this may partly explain why

it is less repellent than the others. Although benzene is not a

terpene compound, it was present at relatively high propor-

tions in lemon and lime oils.

We observed that grapefruit and orange oils shared the

same general composition (Type I) while lemon and lime oils

shared a different general composition (Type II). Thus, the

four oils were divided into two groups to examine the repel-

lent activity of each major monoterpene component.

3. Repellent effect of monoterpenes against Blattella ger-

manica

We tested the repellent efﬁcacy of the monoterpenes and ben-

zene against B. germanica using the olfactometer. The mono-

terpenes were tested with the amounts found in 10

l of the

four citrus oils, which were determined on the basis of GC

and GC/MS data (Table 4). We compared the repellent efﬁ-

cacy of the individual monoterpenes against the efﬁcacy of all

citrus oils tested at 10

l (Table 5). With regard to Type I oils,

limonene comprised more than 90%, and showed repellent ef-

ﬁcacy of 71.0 and 72.4% at doses of 9.24

l and 9.38

l/ﬁlter

paper, which were equivalent to the amounts in 10

l of the

original grapefruit and orange oils, respectively. No signiﬁ-

cant repellent activity was observed for other monoterpenes,

such as

-pinene,

-pinene and

-terpinene, and benzene at

doses found in 10

l of grapefruit and orange oils.

-Myrcene

had no repellent activity either, but had weak attractant activ-

ity at doses of 0.23

l and 0.25

l/ﬁlter paper. Based on these

results and the ﬁnding that the activity of limonene was al-

most identical to that of orange oil, the repellent activity of

orange oil was considered to be solely attributable to

limonene. Since the repellent activity of grapefruit oil was

higher than that of limonene alone, minor components were

likely to have an additive or synergistic effect on the repel-

Vol. 34, No. 2, 77–88 (2009) Repellent efﬁcacy of Citrus oils against cockroaches 81

Tab le 3 . Olfactory response of Periplaneta americana and P. fuliginosa to the four essential oils

Olfactory response

Periplaneta americana Periplaneta fuliginosa

Essential oils

%P%P

Treated Untreated No Treated Untreated No

Side (T) Side (U) choice Side (T) Side (U) choice

Grapefruit 3 28 9 90.3 <0.0001 6 28 8 82.4 <0.0001

Lemon 4 24 12 85.7 <0.0001 7 18 15 72.0 <0.05

Lime 5 25 10 83.3 <0.0001 10 24 6 70.6 <0.05

Orange 9 21 10 70.0 <0.05 9 15 16 62.5 n.s.

Tab le 4 . Ratios of major components of ﬁve Citrus oils identiﬁed by GC and GC/MS

Major Citrus spp. oil (%)

RTa)

Component Grapefruit Lemon Lime Orange Petitgrain

-Pinene 0.16 0.69 2.11 2.40 0.75 0.20

-Pinene 5.27 0.27 13.52 11.66 — 2.50

-Myrcene 7.05 2.32 1.41 1.11 2.53 —

Limonene 8.04 92.35 61.30 47.68 93.79 2.50

-Terpinene 9.43 0.19 4.23 3.40 — 2.00

Benzene 10.23 0.22 8.47 18.29 — —

Linalool 18.00 ————

23.0

Linalyl acetate 21.22 ————50.0

a)Retention time: min.

82 C. Yoon et al. Journal of Pesticide Science

Tab le 5 . Repellency of major components of four Citrus oils against female adults of B. germanica in T-tube olfactometer

Dose No. of insect in

Compound (

l/ﬁlter Treated Untreated No %b)Pc)

paper)a)

side side choice

Type I

Grapefruit 10.00 1 29 10 96.7 0.0001

-Myrcene 0.23 20 13 7 39.4 n.s.

Limonene 9.24 9 22 9 71.0 0.03

-Pinene 0.07 15 14 16 48.3 n.s.

-Pinene 0.03 12 11 17 47.8 n.s.

-Terpinene 0.02 10 12 18 54.5 n.s.

Benzene 0.02 13 16 12 55.2 n.s.

Orange 10.00 8 20 12 71.4 0.04

-Myrcene 0.25 12 8 20 40.0 n.s.

Limonene 9.38 8 21 11 72.4 0.02

-Pinene 0.08 16 14 8 46.7 n.s.

Limonene

-myrcene (9.40.3

l) 10.00 9 17 14 65.4 n.s.

Limonene

-pinene (9.40.1

l) 10.00 11 19 10 63.3 n.s.

Limonene

-pinene (9.40.1

l) 10.00 9 18 13 66.7 n.s.

Limonene

-terpinene (9.40.1

l) 10.00 8 17 16 68.0 n.s.

Limonenebenzene (9.40.1

l) 10.00 15 16 9 51.6 n.s.

LimoneneAd)(9.40.6

l) 10.00 9 19 12 67.9 n.s.

Type II

Lemon 10.00 2 26 12 92.9 0.0001

-Pinene 0.21 10 20 10 66.7 n.s.

-Pinene 1.35 6 16 18 72.7 0.01

-Myrcene 0.14 12 4 24 25.0 0.02

Limonene 6.13 10 21 9 67.7 n.s.

-Terpinene 0.42 8 22 10 73.3 0.02

Benzene 0.85 20 16 4 44.4 n.s.

Lime 10.00 4 26 10 86.7 0.0001

-Pinene 0.24 14 18 8 56.3 n.s.

-Pinene 1.17 10 26 4 72.2 0.01

-Myrcene 0.11 12 4 24 25.0 0.03

Limonene 4.77 11 20 9 64.5 n.s.

-Terpinene 0.34 13 18 9 58.1 n.s.

Benzene 1.83 18 16 6 47.1 n.s.

lency of limonene; however, several artiﬁcial cocktails of

monoterpenes did not reproduce the activity of grapefruit oil

(Table 5), and the additive or synergistic components could

not be identiﬁed in this study.

With regard to Type II oils, limonene at doses of 6.13 and

4.77

l/ﬁlter paper (equivalent to the contents in 10

l lemon

and lime oils, respectively) was not repellent (Table 5). In-

stead,

-pinene at doses found in 10

l of lemon and lime oils

and

-terpinene at the dose found in 10

l lemon oil were sig-

niﬁcantly repellent (72.7, 72.2, and 73.3%, respectively). As

observed in Type I oils,

-myrcene showed attractant rather

than repellent activity at doses of 0.14 and 0.11

l, respec-

tively, which are equivalent to their contents in 10

l of origi-

nal lemon and lime oils.

-Pinene appeared as a weak repel-

lent, but the activity was not statistically signiﬁcant. Benzene

also did not show any signiﬁcant repellent activity. Benzene

was thus excluded from further study.

Since neither of the components alone showed repellency

comparable to the original oils, the repellent activity of Type

II oils is likely to be exerted by the additive or synergistic ef-

fects of multiple constituents; therefore, we tested the various

combinations of monoterpenes.

As shown in Table 5, enhanced repellency was observed

when

-pinene was mixed with limonene at the same ratio as

in the original oil. The addition of limonene to

-terpinene

also increased repellent activity, although the additional effect

was less than that of

-pinene and limonene mixture. The

mixture of

-pinene and limonene showed repellency of

90.3%, almost comparable to that of original lemon and lime

oils. The addition of a third component to this mixture was

not effective in terms of increased repellent activity in every

case tested, and thus, we concluded that the blend of

-pinene

with limonene at a deﬁnite mixing ratio is responsible for the

repellent activity of lemon and lime oils.

In a previous study, it was shown that

-pinene had good

insecticidal activity against female B. germanica in the con-

tact toxicity test.27) It has also been reported that d-limonene

in various essential oils has insecticidal activity against vari-

ous pests.29) d-Limonene is also known to inhibit the growth

of offspring from the oothecae of B. germanica, and such in-

trinsic toxicity is most likely associated with the repellent ef-

fects.30) While d-limonene at high concentrations has been ob-

served to repel various pests, including B. germanica,29,31) we

found here that a lower dose of d-limonene that does not show

repellency alone can repel cockroaches when mixed with

pinene or

-terpinene. These ﬁndings agree with the results of

previous reports, in which essential oil constituents had a syn-

ergistic effect against adults of Lasioderma sericorne.32) The

high repellency of grapefruit oil could not be explained by the

mixture of known components in this study. Since the activity

of grapefruit components in doses less than 1% was not ex-

amined, further study is required to clarify the minor compo-

nents with additive/synergistic effects.

4. Repellency of citrus oil monoterpenes against other

cockroach species

We also examined the repellent efﬁcacies of the major

monoterpene components in citrus oils against P. americana

(Table 6) and P. fuliginosa (Table 7). The components that re-

pelled B. germanica, such as limonene, with an amount

Vol. 34, No. 2, 77–88 (2009) Repellent efﬁcacy of Citrus oils against cockroaches 83

Tab le 5 . (Continued)

Dose No. of insect in

Compound (

l/ﬁlter Treated Untreated No %b)Pc)

paper)a)

side side choice

Limonene

-Pinene (6.10.2

l) 10.00 8 14 18 63.6 n.s.

Limonene

-Pinene (6.11.4

l) 10.00 3 28 9 90.3 0.0001

Limonene

-Myrcene (6.10.2

l) 10.00 8 16 16 66.7 n.s.

Limonene

-Terpinene (6.10.4

l) 10.00 6 22 12 78.6 0.0003

LimoneneBenzene (6.10.9

l) 10.00 7 14 19 66.7 n.s.

Limonene

-Pinene

-Pinene (6.10.21.4

l) 10.00 9 16 15 64.0 n.s.

Limonene

-Pinene

-Myrcene (6.10.20.1

l) 10.00 11 18 11 62.1 n.s.

Limonene

-Pinene

-Terpinene (6.10.20.4

l) 10.00 7 15 18 68.2 n.s.

Limonene

-Pinene

-Myrcene (6.11.40.1

l) 10.00 4 22 14 84.6 0.001

Limonene

-Pinene

-Terpinene (6.11.40.4

l) 10.00 5 23 12 82.1 0.001

Limonene

-Myrcene

-Terpinene (6.10.10.43.4) 10.00 6 21 13 77.8 0.006

a)The mixtures of monoterpenes were made up to 10

l with ethanol before applying to ﬁlter paper. b)Olfactory response (%)Un-

treated/(UntreatedTreated)*100. c)Sign test to evaluate differences from 50 : 50 response (treated and untreated arms, N40, P0.05,

P0.01 and P0.001). n.s., not signiﬁcant. d)Mixture of minor monoterpenes except limonene found in 10

l of original oils.

84 C. Yoon et al. Journal of Pesticide Science

Tab le 6 . Repellency of major components of four Citrus oils against female adults of P. americana in T-tube olfactometer

Dose No. of insect in

Compound (

l/ﬁlter Treated Untreated No %b)Pc)

paper)a)

side side choice

Type I

Grapefruit 10.00 3 28 9 90.3 0.001

-Myrcene 0.23 9 23 8 71.9 0.01

Limonene 9.23 8 22 10 73.3 0.01

-Pinene 0.07 12 19 10 61.3 n.s.

-Pinene 0.03 14 13 12 48.1 n.s.

-Terpinene 0.02 13 15 12 53.6 n.s.

Orange 10.00 9 21 10 70.0 0.05

-Myrcene 0.25 — — — — n.t.

Limonene 9.38 8 23 9 74.2 0.01

-Pinene 0.08 13 16 14 55.2 n.s.

Limonene

-myrcene (9.40.3

l) 10.00 6 16 8 72.7 0.03

Limonene

-pinene (9.40.1

l) 10.00 12 15 13 55.6 n.s.

Limonene

-pinene (9.40.1

l) 10.00 11 16 13 59.3 n.s.

Limonene

-terpinene (9.40.1

l) 10.00 12 16 12 57.1 n.s.

Limonenebenzene (9.40.1

l) 10.00 15 18 7 54.5 n.s.

LimoneneAd)(9.40.6

l) 10.00 8 20 12 71.4 0.02

Type II

Lemon 10.00 4 24 12 85.7 0.001

-Pinene 0.21 10 21 9 67.7 0.05

-Pinene 1.35 10 20 10 66.7 0.05

-Myrcene 0.14 10 21 9 67.7 0.05

Limonene 6.13 8 21 11 72.4 0.01

-Terpinene 0.42 9 21 10 70.0 0.02

Lime 10.00 5 25 10 83.3 0.001

-Pinene 0.24 10 24 6 70.6 0.05

-Pinene 1.17 2 24 14 92.3 0.001

-Myrcene 0.11 11 23 6 67.6 0.05

Limonene 4.77 8 20 12 71.4 0.05

-Terpinene 0.34 11 20 9 64.5 n.s.

equivalent to the content in 10

l Type I oils, and

-pinene

and

-terpinene equivalent to the contents in Type II oils, also

repelled P. americana. In contrast to B. germanica, a small

amount of

-myrcene equivalent to the contents in Type I or II

oils showed signiﬁcant repellent activity against P. americana.

-Terpinene was active at the dose equivalent to the content in

l lemon oil, but was inactive at the dose equivalent to that

in lime oil, which was similar to that of B. germanica.

As for B. germanica, limonene appeared to be mainly re-

sponsible for the repellency of grapefruit oil, but again, its

high activity was not reproducible with any combinations of

its monoterpene components. The mixture of limonene and

myrcene had almost the same activity as limonene or

myrcene alone, and no additive/synergistic effect was ob-

served. By contrast, the repellency of orange oil was mostly

explained by limonene, which was also similar to B. german-

ica.

The highest contents of limonene in lemon and lime oils

suggested that the repellency of these two oils was also

mainly explained by limonene. The addition of

-pinene or

terpinene to limonene slightly enhanced the repellency, but

the addition of

-pinene plus

-terpinene had no further sig-

niﬁcant enhancement. The highest repellent efﬁcacy (83.3%)

was observed when limonene was mixed with

-terpinene

plus

-myrcene, and this was almost equivalent to the activity

of the original oils of lemon and lime. The effect of

myrcene is intriguing, because its addition to limonene caused

hardly any increase in repellency, but caused a considerable

increase when mixed with a combination of limonene and

terpinene. This may suggest the occurrence of complicated

synergistic effects of monoterpenes. With respect to P. ameri-

cana, one study demonstrated that limonene showed no repel-

lent effect against nymphs of P. americana, but benzene deriv-

atives such as eugenol and safrole, and a monoterpene

pinene were active.19) The discrepancy between earlier studies

and the current result may be due to the different conditions

concerning both insects and the different experimental meth-

ods, but it should be mentioned that the repellency of a single

component may be less important if the repellency is exerted

by the interaction of multiple components.

The repellent efﬁcacy of the major monoterpene compo-

nents of citrus oils against P. fuliginosa is shown in Table 7.

As with B. germanica and P. americana, P. fuliginosa were

also repelled by the Type I-oil-equivalent amount of

limonene, and Type II-oil-equivalent amounts of

-pinene

and

-pinene; however, for P. fuliginosa, Type II oil-equiva-

lent amounts of limonene and

-pinene were also active,

which was the case for P. americana, but not for B.

germanica. Conversely, like B. germanica but not P. ameri-

cana,

-myrcene was inactive against P. fuliginosa.

Of the monoterpene components in Type I oils, limonene

showed the highest repellency against P. fuliginosa. In con-

trast to B. germanica and P. americana, the activity of

limonene was higher than the original grapefruit and orange

oils, suggesting that other minor components have some

masking effect on the repellency by limonene. Supporting this

statement, the addition of any monoterpene component to

limonene lowered the repellency compared to limonene alone.

Repellent activity of only 75% was observed when limonene

was mixed with all other monoterpene components found in

l of original oils. Such a masking effect also appeared to

occur with repellency by type II oils. Each monoterpene com-

Vol. 34, No. 2, 77–88 (2009) Repellent efﬁcacy of Citrus oils against cockroaches 85

Tab le 6 . (Continued)

Dose No. of insect in

Compound (

l/ﬁlter Treated Untreated No %b)Pc)

paper)a)

side side choice

Limonene

-Pinene (6.10.1

l) 10.00 5 18 17 78.2 0.005

Limonene

-Pinene (6.11.4

l) 10.00 6 18 16 75.0 0.05

Limonene

-Myrcene (6.10.1

l) 10.00 6 17 17 73.9 0.05

Limonene

-Terpinene (6.10.4

l) 10.00 5 18 17 78.3 0.01

Limonene

-Pinene

-Pinene (6.10.21.4

l) 10.00 6 21 13 77.8 0.01

Limonene

-Pinene

-Myrcene (6.10.20.1

l) 10.00 8 22 10 73.3 0.01

Limonene

-Pinene

-Terpinene (6.10.20.4

l) 10.00 6 24 10 80.0 0.001

Limonene

-Pinene

-Myrcene (6.11.40.1

l) 10.00 6 19 15 76.0 0.01

Limonene

-Pinene

-Terpinene (6.11.40.4

l) 10.00 6 24 10 80.0 0.001

Limonene

-Myrcene 

-Terpinene (6.10.10.4

l) 10.00 5 25 10 83.3 0.001

a)The mixtures of monoterpenes were made up to 10

l with ethanol before applying to ﬁlter paper. b)Olfactory response (%)Un-

treated/(UntreatedTreated)*100. c)Sign test to evaluate differences from 50 : 50 response (treated and untreated arms, N40, P0.05,

P0.01 and P0.001). n.t., not tested; n.s., not signiﬁcant. d)Mixture of minor monoterpenes except limonene found in 10

l of original

oils.

86 C. Yoon et al. Journal of Pesticide Science

Tab le 7 . Repellency of major components of four Citrus oils against female adults of P. fuliginosa in T-tube olfactometer

Dose No. of insect in

Compound (

l/ﬁlter Treated Untreated No %b)Pc)

paper)a)

side side choice

Type I

Grapefruit 10.00 6 26 8 81.3 0.001

-Myrcene 0.23 16 16 8 50.0 n.s.

Limonene 9.23 4 24 12 85.7 0.001

-Pinene 0.07 15 18 7 54.5 n.s.

-Pinene 0.03 12 15 13 55.6 n.s.

-Terpinene 0.02 13 12 15 48.0 n.s.

Orange 10.00 8 20 12 71.4 0.05

-Myrcene 0.25 — — — — n.t.

Limonene 9.38 4 24 12 85.7 0.001

-Pinene 0.08 13 14 13 51.9 n.s.

Limonene

-Myrcene (9.40.3

l) 10.00 8 12 20 60.0 n.s.

Limonene

-pinene (9.40.1

l) 10.00 10 20 10 66.7 n.s.

Limonene

-pinene (9.40.1

l) 10.00 9 18 13 66.7 n.s.

Limonene

-terpinene (9.40.1

l) 10.00 18 12 10 40.0 n.s.

Limonenebenzene (9.40.1

l) 10.00 12 14 14 53.8 n.s.

LimoneneAd)(9.40.6

l) 10.00 8 24 8 75.0 0.01

Type II

Lemon 10.00 10 24 6 70.6 <0.05

-Pinene 0.21 9 21 10 70.0 <0.05

-Pinene 1.35 9 20 11 69.0 <0.05

-Myrcene 0.14 15 16 9 51.6 n.s.

Limonene 6.13 6 23 11 79.3 <0.01

-Terpinene 0.42 6 20 14 76.9 <0.01

Lime 10.00 7 18 15 72.0 <0.05

-Pinene 0.24 9 21 10 70.0 <0.05

-Pinene 1.17 4 18 18 81.8 <0.01

-Myrcene 0.11 16 16 8 50.0 n.s.

Limonene 4.77 7 23 10 76.7 <0.05

-Terpinene 0.34 14 14 12 50.0 n.s.

ponent with signiﬁcant activity showed higher, or almost

equal, at least, repellency, compared to original lemon and

lime oils. Experiments using a mixture of monoterpenes

showed that the addition of

-pinene,

-pinene and

-ter-

pinene to limonene had no increasing effect. By contrast, the

addition of

-myrcene considerably decreased the repellency,

and was likely to be the major masking principle. This also

demonstrates an example of a complicated interaction among

monoterpene components in essential oils, as

-myrcene

alone apparently showed a neutral effect in terms of attraction

and repellency.

Concluding Remarks

This study shows that citrus oils have repellent efﬁcacy

against B. germanica, P. americana and P. fuliginosa. The re-

pellent efﬁcacy was largely due to their main monoterpene

component, limonene, but other major components may also

contribute to the repellent efﬁcacy of these oils. Further stud-

ies examining whether these minor monoterpene components

act additively or synergistically on various cockroach species

are in progress.

Acknowledgments

This study was supported by research grants from the Chungbuk Na-

tional University in 2008 and the Ministry of Education & Human

Resources Development for the Second Stage of Brain Korea 21 Pro-

ject of the Korean Government. We are grateful to the two anony-

mous reviewers for their comments on the manuscript.

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Vol. 34, No. 2, 77–88 (2009) Repellent efﬁcacy of Citrus oils against cockroaches 87

Tab le 7 . (Continued)

Dose No. of insect in

Compound (

l/ﬁlter Treated Untreated No %b)Pc)

paper)a)

side side choice

Limonene

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l) 10.00 6 22 12 78.6 <0.01

Limonene

-Pinene (6.11.4

l) 10.00 4 18 18 81.8 <0.01

Limonene

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l) 10.00 9 17 14 65.4 n.s.

Limonene

-Terpinene (6.10.4

l) 10.00 5 16 19 76.2 <0.05

Limonene

-Pinene

-Pinene (6.10.21.4

l) 10.00 6 23 11 79.3 <0.01

Limonene

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-Myrcene (6.10.20.1

l) 10.00 8 15 17 65.2 n.s.

Limonene

-Pinene

-Terpinene (6.10.20.4

l) 10.00 8 21 11 72.4 <0.05

Limonene

-Pinene

-Myrcene (6.10.11.4

l) 10.00 9 14 17 60.9 n.s.

Limonene

-Pinene

-Terpinene (6.11.40.4

l) 10.00 6 24 10 80.0 <0.001

Limonene

-Myrcene

-Terpinene (6.10.10.4

l) 10.00 14 12 14 46.2 n.s.

a)The mixtures of monoterpenes were made up to 10

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88 C. Yoon et al. Journal of Pesticide Science

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Jul 2023
EUR FOOD RES TECHNOL

Molecular components of citrus essential oils are said to have a wide range of functions, according to findings from several investigations and research projects. An attempt is made to explore the bioactivities of essential oils from citrus and its physiochemical profiles and their beneficial effects upon human wellbeing in this succinct yet thorough overview. Despite being excellent sources of bioactive chemicals, fruit peels are typically underused food industry derivatives. These essential oils components have also been discovered to exhibit insecticidal activities against many varieties of insect species. Numerous investigations have reported that limonene makes up most of the constituent profile of citrus essential oils. Other constituent compounds found in various percentages in different citrus peel essential oils includes, β-citronellal, β-myrcene, β-caryophyllene, linalool, pinene, terpinene, citral etc. The citrus peel essential oils is a good sources of many beneficial chemical compounds with fair amount of phenolic compounds, flavonoids, dietary fibres, other biochemical components like protein, fats, sugars, etc. and chemicals with insecticidal properties. These constituents of Citrus essential oils are impacting a big boost to fight against various diseases. The citrus peel, once wastages have now become industrial inputs with beneficial outputs not only solving the problems of wastage.

Experimental evaluation and structure–activity relationship analysis of bridged-ring terpenoid derivatives as novel Blattella germanica repellent

Article

Dec 2022

Cockroaches are urban pests that are very difficult to control. Using repellents is a green, safe and effective strategy for their control. In order to find novel cockroach repellents, the repellent activity of 45 bridged-ring terpenoid derivatives synthesized from β-pinene against Blattella germanica was tested. The relationship between the molecular structure of these bridged-ring terpenoid derivatives and their repellent activity against Blattella germanica was also analysed. The results show that some of the bridged-ring terpenoid derivatives exhibit good repellent activity against Blattella germanica, and six compounds (RR = 60.44–87.32%) show higher repellent activity against Blattella germanica than DEET (RR = 54.77%), making them promising for development as new cockroach repellents. Quantitative structure–activity relationship (QSAR) analysis revealed that the HOMO-1 energy, Kier and Hall index (order 2), Balaban index, and relative positive charged surface area of bridged-ring terpenoid derivatives have effects on repellent activity against Blattella germanica. The present study may provide a theoretical basis for the high-value use of β-pinene and can be helpful to the development of novel repellents against Blattella germanica.

Chemical Composition and Repellent Activity of Methyl Cinnamate-Rich Basil (Ocimum basilicum) Essential Oil

Article

Full-text available

Oct 2022

Basil (Ocimum basilicum L.) is an important culinary herb and essential oil source widely recognized worldwide. The oil of the plant is beneficial for medicinal uses, and it has many biological activities such as insect repellent, larvicidal, and bactericidal. This study aimed to investigate basil's essential oil for its chemical composition and repellent activity. The essential oil of basil was extracted from fresh leaves by steam distillation method, and the chemical composition of the oil was determined by using GC/MS. Also, the repellent activity of the oil was tested against American cockroaches. Ebeling Choice-Box test with a little modification used in repellence test. The obtained results of chemical composition revealed that the amount of the oil contained forty-one chemical constituents (~97.1%); the major constituents were methyl cinnamate (25.3%), linalool (19.1%) and estragole (12.3%) as the major oxygenated monoterpenes. While α-bergamoten (5.3%), germacrene (4.6%), γ-cadinene (2.8%), and β-elemene (2.4%) were the main compounds in sesquiterpene hydrocarbons. Whereas, in oxygenated sesquiterpenes, Tau-cadinol (4.3%) was an important compounds and ocimene the highest compound in monoterpene hydrocarbons. The obtained results also indicated that the essential oil had good activity against the P. American, at a 100% concentration of oil; the repellence reaches 100% after 1 h. The IC50 and IC90 values of basil essential oil against P. Americans were 53.0 and 83.0%, respectively. The major compound methyl cinnamate which exists in basil essential oil is a very important compound and could be used in a wide area of industrial applications as repellent products, medicinal products, and cosmetics.

The Repellent Potential of Herbal Oils Alone and in Combination in Mouse Behavioral Models (Mus musculus)

Article

Full-text available

Jul 2022

Natural repellent products are of interest worldwide due to their low toxicity, rapid degradation, and being friendly to the environment. The current study evaluated the efficiency of herbal oils from fragrant plants as mouse repellents. Orange oil (Citrus sinensis (L.) Osbeck), peppermint oil (Mentha × piperita L.), lemongrass oil (Cymbopogon citratus (DC.) Stapf), ginger oil (Zingiber officinale Roscoe), plai oil (Zingiber cassumunar Roxb.), menthol and their combination were tested in a radial arm maze and light/dark transition test. For the short-term effect (week 0), each of the herbal oils and their combination were effective as mouse repellents, as shown by increased latency times and decreased time spent in arms containing repellents in the radial arm maze. Similarly, mice exposed to each of the herbal oils and their combination in the dark chamber spent more time in the light chamber in the light/dark transition test. Only peppermint oil and menthol failed to maintain their repellent activity in the long-term effect (week 1). Thus, we recommend spraying orange oil, lemongrass oil, ginger oil, plai oil and the combination of all oils every week for effective mouse repellant activity. Keywords: Medicinal plant, Mice, Natural product, Essential oils, Anxiety

Utilization of Pomelo (Citrus maxima) Peel Waste into Bioactive Essential Oils: Chemical Composition and Insecticidal Properties

Article

Full-text available

May 2022

The wastes generated during the post-harvest handling of various agricultural commodities is rather under-utlilized. The peels of citrus fruits are often discarded as waste. Citrus peels are rich in essential oils and exhibit toxicity towards various insect species. The essential oils are also an eco-friendly option for insect pest management. The Citrus maxima peel essential oil (CMEO), a waste product, characterized it, and evaluated its potential for insect pest management. The major terpenoids present in CMEO are Limonene and α-Pinene. The CMEO displayed potentials in controlling the insect pests via contact and fumigant toxicity. Moreover, CMEO showed significant larvicidal activities against Culex tritaeniorhynchus and Aedes aegypti species of mosquitoes; however, Armigeres subalbatus was more resistant. The biological safety of the essential oil was also tested against the stored seeds, where no significant inhibition of seed germination was noticed compared to the control. Utilizing a waste product such as citrus peel for pest management can achieve the dual objective of waste utilization and eco-friendly pest management. Overall, the CMEO is therefore found to be a bioactive essential oil extracted from the wastes of pomelo (C. maxima).

Toxicity and context-dependent repellency of temporarily granted repellents under new biocidal products regulations in South Korea against Drosophila melanogaster (Diptera: Drosophilidae)

Article

Mar 2022
J Asia Pac Entomol

In South Korea, control agents for small flying insects are subjected to approval under newly enforced Act on biocidal products by the Ministry of Environment starting from 2019, along with other conventional household insecticides. The present study aimed to evaluate 18 compounds for their toxicity and repellency in various contexts. A tube assay revealed the greatest toxicity of synthetic repellent DEET. Interestingly, spatial repellency of several plant essential oils was greater than those of conventional repellent, indicating their suitability for temporal grants. Meanwhile, unlike conventional repellents, botanical oils often lost their choice repellency in gaseous unsaturable condition. Spatial repellency was positively correlated to the evaporation rate of the compounds while choice repellencies were negatively correlated regardless of their gaseous saturability. Our results are expected to provide implications for both the regulation process and product development.

Effect of Some Essential Oils on American Cockroach Periplaneta Americana L

Article

Full-text available

Apr 2022

Essential oils were extracted from Syzqiumoramac clove, Nigella sativa and eucalyptus oil for purpose of studying effect of these oils on adult cockroaches as repellents and extent of their attraction to them by treating biscuits with three concentrations (0.5, 0.25,1%). The results showed that clove oil was significantly more repellent than black seed oil at a concentration (1%), as average for five days was (0.32) compared to black seed oil (1.36). Insects attracted towards lunch averaged 7.58, 14 and this indicates fading of repellent effect due to penetration of the aroma of volatile clove oil. Results also showed that clove oil has a more lethal effect by direct spraying on nymphs and adults than black seed oil, as mortality in a specific time period of death for adults was 11.93 and nymphs 6.57, compared to black seed oil, the death rate of adults was 6.66, while for nymphs it was 3.46, which leads to the consideration of oil Clove oil has a more repellent and deadly effect than black seed oil.

Spatial distribution of synanthropic cockroaches found in Quetta, Pakistan and antibiotic-resistant bacteria strains found in Shelfordella lateralis (Walker, 1868) (Blattodea: Blattidae)

Article

Full-text available

Nov 2021
Entomol Res

Synanthropic cockroaches are a public health concern, because they can carry pathogens and allergens. These insects inhabit urban spaces and must be constantly monitored in order to assess the pest emergence outbreaks. Here, we combined spatial population monitoring with microbiological testing to survey the main pest cockroach species found inside residences of the city of Quetta, Pakistan. We evaluated the distribution of pest cockroaches at two scales: landscape (neighborhood) and patch (inside houses). We found at least one of the following pest species in the 73.2% of the total residences surveyed (n = 112): Shelfordella lateralis 37.1%, Periplaneta americana 23%, Blatella germanica 16.7%, Blatta orientalis 13.4% and Polyphaga aegyptiaca 9.8%. At landscape scale, the most common was S. lateralis, presenting a clustered distribution in two sampled zones, also heavily urbanized. At indoor scale, S. lateralis were most frequently found in kitchens. When we studied the bacterial loads in this species, we found that S. lateralis carried several pathogenic bacteria. Susceptibility tests tested on these strains against 10 common formulations showed antibiotic resistance for some bacteria. For instance, Pasteurella spp was susceptible towards six antibiotics tested, while Helicobacter spp showed resistance against eight antibiotics tested. Our evidence suggests that S. lateralis have the potential to displace main cosmopolitan pests and, most concerning, also carry antibiotic-resistant pathogenic bacteria. Considering that this emergent Asian-native pest is now present in Europe and America, it may correspond to a relevant urban pest deserving further international public health attention.

Repellency of Rosemary Oil and Its Components against the Onion Aphid, Neotoxoptera formosana (TAKAHASHI) (Homoptera, Aphididae)

Article

Full-text available

May 1997

Olfactory behaviors of Neotoxoptera formosana, an aphid pest of allium crops, to host and non-host plant odors were investigated with a linear track olfactometer. Aphids were significantly attracted to odors of host plants, Allium fistulosum and A. tuberosum. On the contrary, they were repelled by odors of non-host plants, rosemary and pennyroyal. The odor of pennyroyal masked the attractiveness of host plant odor and the odor of rosemary repelled aphids even in the presence of host plant odor. Rosemary oil also had a repellency effect against aphids, and repelled them even in the presence of host plant odor. Six components of rosemary oil identified by GC-MS analysis, 1,8-cineole, d,l-camphor, α-pinene, etc., showed this repellency as well. 1,8-Cineole and d,l-camphor repelled aphids even in the presence of host plant odor and α-pinene masked host plant attractancy. 1,8-Cineole is the main component of rosemary oil and is thought to be main factor responsible for the repellency of rosemary. It was concluded that N. formosana may use host plant odors for host selection and be repelled by certain non-host plant odors. Rosemary volatiles may play an important role in defense of the plants from attack by parasites.

Insecticidal Properties of d-Limonene

Article

Full-text available

Jan 1988

: d-Limonene (p-mentha-1,8-diene) is a monocyclic monoterpenoid found in citrus oils. The spectrum of insecticidal activity of d-limonene was examined by using the German cockroach, Blattella germanica (L.), house fly, Musca domestica L., rice weevil, Sitophilus oryzae (L.), and western corn rootworm, Diabrotica virgifera virgifera leconte. bioassays were performed to determine topical, fumigant, oral, repellent, residual, ovicidal, and larvicidal activities. The material was slightly toxic topically to German cockroaches and house flies and was synergized with piperonyl butoxide. High concentrations of vapors caused mortality in German cockroaches and rice weevils. Oral administration did not result in mortality to either adult or nymphal cockroaches but accelerated growth in nymphs. Repellent activity against German cockroaches was noted at high concentrations. No residual activity was observed on any of four surface types exposed to adult German cockroaches. d-Limonene inhibited western corn rootworm egg hatch at high concentrations and showed moderate toxicity in soil against third-instar western corn rootworm larvae. These findings indicate that the insecticidal properties of d-limonene are limited. © 1988, Pesticide Science Society of Japan. All rights reserved.

Adulticidal Activity of Five Essential Oils against Culex pipiens quinquefasciatus

Article

Full-text available

Jun 2005

The aim of this study is to observe the adulticidal activity of five essential oils against the mosquito Culex pipiens quinquefasciatus. Fumigating adulticidal activity was investigated by airtight fumigation in conical flasks. The result showed that the toxic effect of the five essential oils varied with the period of fumigation. Rutaceae oil was the most toxic of the five. Carvacryl oil had the shortest adulticidal time (6.087 min). The chemical components of rutaceae oil were analyzed by GC/MS. The major components were alpha-citral (33.50%) and citral (35.77%). Citral showed marked adulticidal activity in a short-term fumigation. All five essential oils had considerable adulticidal effects on Cx. pipiens quinquefasciatus. (c) Pesticide Science Society of Japan.

Repellency of essential oils against the cigarette beetle, Lasioderma serricorne (Fabricius) (Coleoptera: Anobiidae)

Article

Full-text available

Nov 2003

Masatoshi Hori

The behavioral responses of the female cigarette beetle to 57 plant essential oils commonly used for the flavoring of foods and cosmetics, were investigated with an olfactometer. Forty-eight of these essential oils exhibited repellency and only patchouli oil exhibited attractiveness at a dose of 1 μl. The repellency of the 28 essential oils that strongly repelled the beetles at this dose were furthermore evaluated at a dose of 0.1 μl. Six plant oils (shiso, savory, cassia, thyme, peppermint and Litsea cubeba oils) strongly repelled the beetles at this dose. Then, the dose-responses of these six oils on repellency against the beetles were investigated. These oils exhibited attractiveness at lower doses than each threshold except shiso oil, which did not attract the beetles at any doses tested. The first major components of these six oils repelled the beetles at a dose of 1 μl or 1 mg. However the repellency of these components was less than that of each essential oil. The repellency of shiso oil in the presence of cured tobacco odor, which attracted the beetles, was further evaluated. Shiso oil repelled the beetles at a dose of 10 μl even in the presence of the tobacco odor.

Effects of a low temperature on the survival and development of four species of cockroaches, Blattella germanica, Periplaneta americana, P. fuliginosa and P. japonica

Article

Jan 1973

The powers of survival of 4 species of cockroaches under a low temperature of 5.5±0.5℃ were investigated. No any stage of Periplaneta americana and Blattella germanica could tolerate the chilling treatment of 40 days. Nymphs of older instars of P. fuliginosa survived for 90 days and some oothecae for more than 80 days under the chilling treatment, when given an exposure to 15±1℃ beforehand. Most of nymphs and adults of P. japonica tolerated the chilling treatment for more than 90 days with the preliminary exposure. These results suggest that P. americana and B. germanica hardly survive the coldest 3 months outdoors or in unheated buildings in Central Japan, whereas P. fuliginosa and P. japonica tolerate the winter under outdoor conditions.

Biostatistical Analysis (2nd ed.).

Article

Jun 1986

New Methods of Evaluation for Cockroach Repellents and Repellency of Essential Oils against German Cockroach (Blattella germanica L.)

Article

Jan 1982

Shin-Ichi Inazuka

Two new techniques to evaluate repellency against the German cockroach (Blattella germanica L.) were devised, a test tube method and a beaker method. The former estimates the repellent impact on a roach attracted by roach excrement on a paper filter. The latter, estimating effectiveness by changes in the number of roaches in a beaker, is an excellent method for evaluating olfactory repellency. Among the reference compounds, α-naphthoquinone, 2-hydroxyethyl-n-octylsulfide and naphthalene were effective in the test tube method, however their 2% sublimates were not effective in the beaker method. Those compounds were thus not judged as promising olfactory repellents. The oils of Japanese mint (Mentha arvensis) and spearment (native and Scotch type, Mentha specata) were the most effective among 92 such substances. Strong mosquito repellents such as oils of citronella, lavender, rosemary, and penny royal had little or no effect against the cockroach.

Insecticidal and repellent properties of Piper guineense seed oil extract for the control of maize weevil, Sitophilus zeamais

Article

Jan 2006

Elechi FRANCA Asawalam

The repellency of the acetonic oil extracts of Black pepper, Piper guineense (Schum and Thonn) (Family: Piperaceae) were evaluated against Maize weevil Sitophilus zeamais (Motschulsky) at 30 0 C, 65 ± 2% R.H and 12h: 12h light:dark regimes in the laboratory. The different dosages used were 25, 50, 75, 100, and 125 mg. All the dosages tested evoked a repellency of the highest class 80.1-100% in S. zeamais adults. The proximate and chemical analysis revealed that there was no adverse effect on the basic food components and mineral elements in the grains treated with P. guineense seed oil and powder but the grains treated with P. guineense seed oil performed best. The sensory evaluation test revealed that the boiled maize from treated grains after 3 months of storage were of normal colour, taste and texture in all the treatments hence, the overall acceptability score was not adversely affected. The strong repellent property of P. guineense seed oil implies that stored maize may be adequately protected against population of S. zeamais thus reducing their infestation level.

Insecticidal, antifeedant and oviposition deterrent effects of the essential oil and individual compounds from leaves ofChloroxylon swietenia DC

Article

Nov 2006

Essential oil from the leaves of Chloroxylon swietenia DC. was obtained by hydrodistillation and cold extraction, and the chemical composition was determined by gas chromatography and gas chromatography-mass spectrometry. The major identified components were limonene, geijerene, pregeijerene, germacrene D and trans-beta-ocimene. Laboratory bioassays of the essential oil and four constituents of essential oil isolates were evaluated for insecticidal, antifeedant and oviposition deterrent effects on tobacco cutworm, Spodoptera litura (F.). Toxicity was determined by topical application of the isolates at varying concentrations. Pure oil, geijerene and pregeijerene were found to be more toxic, with LD50 values of 28.6, 35.4 and 40.7 microg per larva respectively. Maximum feeding deterrence was noted for geijerene and pregeijerene, with DC(50) values of 82.5 and 95.1 microg cm(-2) respectively. Furthermore, pure oil, geijerene and pregeijerene displayed oviposition deterrence, even at low concentrations. These results indicate that these natural products may lead to useful, biodegradable, environmentally safe insect control agents.

Biostatistical Analysis: New Jersey: Prentice-Hall

Article

Jan 2010

Jerrold H. Zar

Repellent activity of citrus oils against the cockroaches Blattella germanica, Periplaneta americana and P. fuliginosa

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