ArticlePDF Available

Genetic evidence for two introductions of the Formosan Subterranean Termite, Coptotermes formosanus (Isoptera : Rhinotermitidae), to the United States

Authors:

Abstract and Figures

Las introducciones exóticas de la termita subterránea de Formosa (TSF) de Asia a los Estados Unidos han tenido consecuencias económicas significativas. Introducciones multiples por medio del transporte marino han sido propuestas, pero la identificación de estas rutas todavia no ha revelada mas que un linaje en los Estados Unidos continental. La secuenciación de un marcador de 640-bp del citocromo-c-oxidasa II de ADN mitochondrial (mtADN) a 60 poblaciones separadas, revelo dos linajes independientes atravesando los Estados Unidos continental, Hawaii, Japan y China. El marcador mostró una variación genética limitada. El grupo I constituye un clado principalmente asiático, mientras el grupo II consiste de poblaciones asiáticas y del sur de los Estados Unidos. Este es el primer estudio que documenta los dos linajes distintas en los Estados Unidos y Hawaii.
Content may be subject to copyright.
Austin et al.:
Coptotermes formosanus
Genetics 183
GENETIC EVIDENCE FOR TWO INTRODUCTIONS OF THE
FORMOSAN SUBTERRANEAN TERMITE,
COPTOTERMES FORMOSANUS
(ISOPTERA: RHINOTERMITIDAE), TO THE UNITED STATES
J
AMES
W. A
USTIN
1
, A
LLEN
L. S
ZALANSKI
2
, R
UDOLF
H. S
CHEFFRAHN
3
, M
ATT
T. M
ESSENGER
4
,
J
ACKIE
A. M
C
K
ERN
2
AND
R
OGER
E. G
OLD
1
1
Center for Urban and Structural Entomology, Department of Entomology
Texas A&M University, College Station, TX 77843-2143
2
Department of Entomology, University of Arkansas, Fayetteville, AR 72701
3
Department of Entomology, University of Florida-Ft. Lauderdale Research and Education Center
3205 College Avenue, Ft. Lauderdale, FL 33314
4
Dow AgroSciences LLC, 9330 Zionsville Road, Indianapolis, IN 46268
A
BSTRACT
Exotic introductions of Formosan Subterranean Termite (FST) to the United States from
Asia have had significant economic consequences. Multiple introductions through marine
transport have been proposed, but identification of these routes has yet to reveal more than
one lineage in the continental U.S. DNA sequencing of a 640-bp cytochrome oxidase II (COII)
mitochondrial DNA (mtDNA) marker to 60 disjunct populations, revealed two independent
lineages spanning the continental U.S., Hawaii, Japan, and China. Limited genetic variation
was observed with this marker. Group I constitutes a largely Asian clade, while Group II is
comprised of both Asian and southern U.S. populations. This is the first study which has doc-
umented 2 distinct lineages to continental United States and Hawaii.
Key Words:
invasive species
,
DNA sequence, genetic variation, molecular diagnostics, termite
R
ESUMEN
Las introducciones exóticas de la termita subterránea de Formosa (TSF) de Asia a los Esta-
dos Unidos han tenido consecuencias económicas significativas. Introducciones multiples
por medio del transporte marino han sido propuestas, pero la identificación de estas rutas to-
davia no ha revelada mas que un linaje en los Estados Unidos continental. La secuenciación
de un marcador de 640-bp del citocromo-c-oxidasa II de ADN mitochondrial (mtADN) a 60
poblaciones separadas, revelo dos linajes independientes atravesando los Estados Unidos
continental, Hawaii, Japan y China. El marcador mostró una variación genética limitada. El
grupo I constituye un clado principalmente asiático, mientras el grupo II consiste de pobla-
ciones asiáticas y del sur de los Estados Unidos. Este es el primer estudio que documenta los
dos linajes distintas en los Estados Unidos y Hawaii.
Formosan subterranean termite (FST)
Copto-
termes formosanus
Shiraki (Isoptera: Rhinoter-
mitidae), has long been suspected to have origi-
nated from Formosa (the Island of Taiwan), but
endemic to mainland China due to the identifica-
tion of a termitophile from there (Kistner 1985).
FST has been reported from 14 southern prov-
inces in China with a northern limit of 33°28’ N
and a western limit of 104°35’E (Gao et al. 1982;
He & Chen 1981; Lin 1986) (Fig. 1). Introductions
of this exotic pest have been documented around
the world following closely with trade routes ex-
tending to the United States and beyond (Chho-
tani 1985). Historical shipping trade between the
east and west over the past 450 years (Welsh
1996; Lim 1997), and the likely introduction(s) of
FST to the continental U.S. after World War II (La
Fage 1987), have made tracking introduction
points difficult. Trading centers in Guangdong
Province (e.g., Macau, Guangzhou, Shenzhen,
and Hong Kong), Fujian Province (e.g., Puyuan)
and Shanghai Province, China, and Taiwan have
provided likely ports of origin for FST (See Prov-
ince Map, Fig 1). Gay (1967) suggests that intro-
ductions of FST into Guam, Midway Island, the
Marshall Islands, and the Hawaiian islands are
most likely due to shipping trade.
FST is believed to have been introduced to
Japan almost 300 years ago (Mori 1987; Su &
Tamashiro 1987; Wang & Grace 1999; Vargo et al.
2003), and has been hypothesized to have been in-
troduced to Hawaii almost 100 years ago (Su &
Tamishiro 1987). The history of FST introduc-
tions to the continental United States is more am-
184
Florida Entomologist
89(2) June 2006
biguous because of likely misidentifications. For
example, early samples of
Coptotermes
in Hous-
ton, Texas, during the 1950s were identified as
C. crassus
Snyder, but were later positively iden-
tified as
C. formosanus
.
Presently, FST is distributed across the south-
east United States (Spink 1967; Howell et al.
1987; La Fage 1987; Su & Tamashiro 1987; Appel
& Sponsler 1989; Chambers et al. 1998; Su &
Scheffrahn 1998a; Cabrera et al. 2000; Haw-
thorne et al. 2000; Howell et al. 2000; Su & Schef-
frahn 2000; Hu et al. 2001; Scheffrahn et al. 2001;
Jenkins et al. 2002), and disjunct populations in
southern California (Atkinson et al. 1993;
Haagsma et al. 1995) are thought to have origi-
nated from Hawaii. Without doubt, their contin-
ued presence and growing distribution(s) have
been exacerbated by commerce and trade prac-
tices within the United States (Cabrera 2000;
Jenkins et al. 2002; Glenn et al. 2003), and by the
general lack of education and research funding di-
rected towards this problem until recently (Oper-
ation Full Stop, a FST interdiction research unit
located in New Orleans, Louisiana was initiated
by the United States Department of Agriculture,
Agricultural Research Service in 1998).
Several studies applying genetic or biochemi-
cal interpretations of FST populations have at-
tempted to identify introduction routes of FST.
However, while multiple entry points appear
likely, the lack of genetic variation in this inva-
sive species has made identification of these
routes difficult to achieve. Studies applying cutic-
ular hydrocarbons (Haverty et al. 1990), alloz-
ymes (Korman & Pashley 1991; Strong & Grace
1993; Broughton & Grace 1994; Wang & Grace
2000), mitochondrial DNA (mtDNA) (Jenkins et
al. 2002), and microsatellite DNA (Vargo & Hend-
erson 2000; Husseneder & Grace 2000; 2001a, b;
Husseneder et al. 2002) have been reported, but
current literature has not conclusively estab-
lished the origins of alternative routes to the
United States. These studies have implicated that
more than one introduction route existed, but
Fig. 1. Provincial Map of China based on Wang et al. (2002). Shaded provinces reflect areas with known Copto-
termes formosanus infestations.
Austin et al.:
Coptotermes formosanus
Genetics 185
they have not corroborated their suppositions
with the inclusion of additional FST populations
which might elucidate this observation.
Presumably, this could be attributed to the
overall lack of genetic diversity of FST globally. In
introduced populations, the lack of clear colony
boundaries and the potential for considerable
mixing of individuals among colonies may lead to
the formation of colonies which could extend over
large areas making colonial identity difficult, an
observation observed in unicolonial ant species
(Argentine ant
Linepithema humile
) (Tsutsui et
al. 2000, 2001). Alternatively, it may be that the
natural dispersal of FST alates is more signifi-
cant than previous recorded distances (Messen-
ger & Mullins 2005), an explanation proposed for
the low mitochondrial DNA (mtDNA) divergence
among sites spanning across states such as Geor-
gia (Jenkins et al. 2002). However, human-aided
dispersal of FST would be equally plausible as a
contribution to low mtDNA divergence. Some ar-
gue that the lack of genetic diversity in FST could
be due to genetic bottlenecks (Strong & Grace
1993; Broughton & Grace 1994) with limited
founder effect. Others suggest the possibility of
significant inbreeding due to neotenic involve-
ment (Wang & Grace 1995). For this to be accept-
able, one must assume that there would be some
inbreeding depression or fixation.
Herein, we report that while multiple intro-
ductions of FST (to the United States) are pre-
sumed, limited genetic variation in this species
restricts the clarification of exactly where these
exotic introductions originated from when using
some molecular markers. We provide evidence of
2 distinct lineages, occurring in the continental
United States and in the Hawaiian Islands, with
identical lineages from China.
M
ATERIALS
AND
M
ETHODS
Coptotermes formosanus
were collected from
all known continental United States where FST
has been reported, the Hawaiian Islands, Japan,
Hong Kong, and China (Table 1). Morphological
identification of specimens used in this study
were performed by applying the keys of Schef-
frahn et al. (1994), and verified with a FST molec-
ular diagnostic method (Szalanski et al. 2004).
Voucher specimens, preserved in 100% ethanol,
are maintained at the Arthropod Museum, De-
partment of Entomology, University of Arkansas,
Fayetteville, AR, the University of Florida-Ft.
Lauderdale Research and Education Center, Ft.
Lauderdale, FL, and the Center for Urban and
Structural Entomology, Department of Entomol-
ogy, Texas A&M University, College Station, TX.
Alcohol preserved specimens were allowed to
dry on filter paper, and DNA was extracted from
individual worker, or soldier heads by using the
Puregene DNA isolation kit D-5000A (Gentra,
Minneapolis, MN). Extracted DNA was resus-
pended in 50 µL of Tris:EDTA and stored at
-20°C. Polymerase chain reaction (PCR) was con-
ducted with the primers TL2-J-3037 (5-ATGGCA-
GATTAGTGCAATGG-3) designed by Liu and
Beckenbach (1992) and described by Simon et al.
(1994) and Miura et al. (1998), and primer TK-N-
3785 (5-GTTTAAGAGACCAGTACTTG-3) from
Simon et al. (1994). These primers amplify a 3’
portion of the mtDNA COI gene, tRNA-Leu, and a
5’ section of the COII gene. PCR reactions were
conducted with 1 µL of the extracted DNA (Sza-
lanski et al. 2000), with a profile consisting of 35
cycles of 94°C for 45 s, 46°C for 45 s, and 72°C for
60 s. Amplified DNA from individual termites
was purified and concentrated by using Microcon-
PCR Filter Units (Millipore, Bedford, MA).
Samples were sent to The University of Arkan-
sas Medical School DNA Sequencing Facility (Lit-
tle Rock, AR) for direct sequencing in both direc-
tions with an ABI Prism 377 DNA sequencer (Fos-
ter City, CA). To facilitate genetic comparison
with existing GenBank DNA sequences, 113 bp
from the 5’ end of the sequence was removed, and
the remaining 667 bp was used. GenBank acces-
sion numbers for the FST haplotypes found in
this study are AY453588 and DQ386170. DNA se-
quences were aligned with BioEdit version 5.09
(Hall 1999) and Clustal W (Thompson et al. 1994).
The distance matrix option of PAUP* 4.0b10
(Swofford 2001) was used to calculate genetic dis-
tances according to the Kimura 2-parameter
model (Kimura 1980) of sequence evolution.
R
ESULTS
AND
D
ISCUSSION
Introduction of exotic termites to the United
States is an ongoing problem that is invariably
sustained by modern trade and limited or non-ex-
istent quarantine regulations.
Native populations (in China) of FST should
possess greater genetic diversity. For this reason,
focusing on the nature of genetic variation in pop-
ulations from China and neighboring Asian coun-
tries (Vargo et al. 2003) is a logical starting point
when evaluating the nature of introduced popula-
tions to the United States (Husseneder et al.
2002) and its territories. In the present study we
evaluated native populations of FST from Guang-
dong, Shanghai, and Fujian provinces (Hong
Kong, Puyuan, Guangzhou, and Xhinhui) in
China. However, only two distinct COII haplo-
types were observed.
Applying
C. acinaciformis
(Froggatt),
C. lacteus
(Froggatt), and
Heterotermes cardini
(Snyder) as
outgroups, Haplotype group I contains locations
from Hong Kong, Japan AB109529, Hsin-Hui
(presently known as Xhinhui), China (from Jen-
kins et al. 2002), Puyuan and Guangzhou, China,
Oahu, HI, Nagasaki, Japan, and Ft. Worth, TX
[presumably this sample was collected from
186
Florida Entomologist
89(2) June 2006
Grapevine, TX, because the only known occur-
rences of FST in Tarrant County, TX, occur in the
Northeast portion of this county (pers. Comm.
Mike Merchant)]. Group II contains several FST
populations from disjunct locations: Hong Kong,
North Carolina, South Carolina (Jenkins et al.
2002), Georgia, Florida, Alabama (Jenkins et al.
2002), Mississippi, Louisiana, Texas, Oahu and
Maui, HI (Figs. 2 and 3). Representative taxa from
group I were slightly more divergent based on
Maximum likelihood analysis (Fig. 3). Inclusion of
FST sequence data from Jenkins et al. (2002), des-
ignated by their respective haplotype descriptions
(A through H), also fall within the two groups pre-
sented herein (Table 2, Figs. 2 and 4).
Fei and Henderson (2003) noted that incipient
colony establishment was somewhat more restric-
tive for outbred primary reproductives, owing dis-
crepancies to environmental adaptive resource
differences from two disjunct populations from
Louisiana. Furthermore, Coaton & Sheasby
(1976), and Lenz & Barrett (1982) suggest that
dominant use of neotenics for colony growth in
C. formosanus
may be a successful strategy to in-
T
ABLE
1.
C
OPTOTERMES
FORMOSANUS
COLLECTION
DATA
.
Location Country N Hap Source
Hong Kong China 3 1 This study
Asia 1 1 AB109529
Ft. Worth, TX USA 1 E(1) Jenkins et al. 2002
Oahu, Hawaii USA 1 1 This study
Hong Kong China 2 2 This study
HI USA 1 2 AY536406
Maui, HI USA 2 2 This study
GA USA 2 2 AY536405, AY027489
Cairo, GA USA 2 2 AY683220
Lawrenceville, GA USA 1 2 AY683213
Tucker, GA USA 1 2 AY683214
Dallas, GA USA 1 2 AY683214-15
Savannah, GA USA 2 2 AY683217-219
GA USA 1 2 This study
Spindale, NC USA 1 2 This study
Forest City, NC USA 1 2 This study
Rutherfordton, NC USA 1 2 This study
Marco Island, FL USA 1 2 This study
Trinity, FL USA 1 2 This study
Niceville, FL USA 1 2 This study
Florida City, FL USA 1 2 This study
Temple Terrace, FL USA 1 2 This study
Palm Beach, FL USA 1 2 This study
Pompano Beach, FL USA 1 2 This study
Galveston, TX USA 2 2 This study
San Antonio, TX USA 1 2 This study
Garland, TX USA 1 2 This study
Rockwall, TX USA 1 2 This study
Stennis Sp Ctr, MS USA 4 2 This study
New Orleans, LA USA 2 2 AY536407,AY683217
Lake Charles, LA USA 3 2 This study
New Orleans, LA USA 3 2 This study
St. Rose, LA USA 1 2 This study
New Orleans, LA USA 1 B(2) Jenkins et al. 2002
SC USA 1 C(2) Jenkins et al. 2002
Nagasaki Japan 2 2 This study
Puyuan China 1 3 AY536403
Guangzhou China 1 4 AY536404
Mobile, AL USA 1 D Jenkins et al. 2002
GA USA 1 A Jenkins et al. 2002
Hsin-hui (Xhinhui) China 1 G Jenkins et al. 2002
Hsin-hui (Xhinhui) China 1 H Jenkins et al. 2002
Oahu, HI USA 1 F Jenkins et al. 2002
Austin et al.:
Coptotermes formosanus
Genetics 187
Fig. 2. Maximum Parsimony Analysis of
Coptotermes formosanus
lineages in North America. For consistency,
open and closed circles reflect the different mtDNA COII lineages of
C. formosanus
, while the numbers are used for
comparison and clarification of geographic location in Figures 3 and 4.
188
Florida Entomologist
89(2) June 2006
vade new environments. If this adaptive strategy
is true for
C. formosanus
, reduced genetic varia-
tion may be the result and would account for some
of the limited population viscosity observed to
date. Habitat fragmentation and anthropogenic
disturbances significantly reduce population vis-
cosity. More comprehensive studies of FST may
not reveal significant genetic diversity. For FST,
reduced genetic variation does not necessarily
mean reduced fitness or vigor, but may simply im-
ply that there is greater reproductive plasticity.
For example, Hyashi et al. (2004) demonstrated
that
Reticulitermes speratus
(in Japan) can utilize
facultative parthenogenic reproduction. This
would be a significant establishment capability
for termites like FST when introduced to non-en-
demic locations such as the United States.
There have been numerous emigrations of peo-
ple to Hong Kong throughout history. Major migra-
tions of Chinese settlers from mainland China to
Hong Kong have been recorded as early as the
Song Dynasty (960-1279) (Welsh 1996). After the
end of World War II and the communist takeover of
mainland China in 1949, hundreds of thousands of
people emigrated from China to Hong Kong (Welsh
1996). In fact, locations such as Xhinhui, a treaty
port in 1904, was an important outlet for Chinese
emigrants to the United States (Anonymous 2004).
The introduction of FST to the U.S. likely occurred
several times, perhaps more than ten different oc-
casions (RHS, personal communication). Given
this fact, it is remarkable that the established link
between the U.S. and China has never been sub-
stantiated for more than one FST lineage.
Populations of FST from Japan appear only in
one of the presented clades (Group I, Fig. 2), and
further sampling from more locations (in Japan)
may provide additional information on whether
Japan could have contributed more significantly
to FST introductions to Hawaii or the continental
United States. Group I (Fig. 2) is largely com-
prised of samples from Asian/Pacific locations but
has one sample (Ft. Worth, TX) that was collected
in the continental U.S. (Fig. 3). This is significant
because it implicates a second introduction route
to the continental U.S. that has never been iden-
tified in previous studies. Group II, is comprised
of FST samples from nearly all known southeast-
ern states (Alabama, Florida, Georgia, Louisiana,
Mississippi, North Carolina, South Carolina),
Texas, Hawaii, and several FST from China. Both
clades are well-supported by strong bootstrap
support (>80%) by both parsimony and Liklihood
analyses (Figs. 1 and 3).
Although FST distributions have been more
recently updated (Wang et al. 2002), the lack of a
Fig. 3. Introduction routes of Coptotermes formosanus from Asia to North America. Dashed arrow pointing to-
wards Southern California suggests the introduction from Hawaii based on anecdotal information that has not been
corroborated in genetic studies to date.
Austin et al.:
Coptotermes formosanus
Genetics 189
geographic explanation for a second lineage intro-
duced to the United States remains unclear
(Wang & Grace 2000). Sequence data obtained
from GenBank, from Jenkins et al. (2002), pro-
vides a second haplotype match in the continental
United States (haplotype E from Ft. Worth, TX)
that represents the first documented case corrob-
orating multiple lineages from presumably multi-
ple introductions (at least two in the present
study). These two distinct haplotypes share one
commonality—both groups have representatives
with identical haplotypes (lineages) from Hong
Kong, Japan, Hawaii, and the continental United
States (Fig 3).
There were numerous FST samples where re-
peated attempts to amplify sufficient DNA for se-
quencing of the mtDNA COII gene were not suc-
cessful (e.g., FST from San Diego, California and
Tai Chuong, Taiwan). These results were not sur-
prising, as we have routinely observed ~60% effi-
ciency when using the COII marker with FST.
However, amplification of the 16S rRNA for these
samples was successful. We routinely observe
>90% efficiency for this marker with FST. While
the utility of the 16S marker is excellent for phy-
logenetic studies of the genus
Coptotermes
(JWA,
unpublished), for molecular diagnostic methods
(Szalanski et al. 2004), or other rhinotermitids
(Szalanski et al. 2004; Austin 2004a; 2004b), it
does not provide the degree of genetic variation
suitable to discern the two distinct FST haplo-
types observed in this study. The slightly larger
COII amplicon (640 bp versus 428 bp of 16S
rRNA) provides only a small increase in resolu-
tion between FST populations, even though it
works well for other Rhinotermitidae (Austin et
al. 2002, 2004c). Our laboratory experience with
FST suggests that in general, it is more difficult
to extract high quality DNA from Coptotermes for
genetic studies when compared to other rhinoter-
mitids, a problem that may be more common than
reported. Additional problems may include the
presence of unknown inhibitors, method of sam-
ple preservation (some preservation methods are
known to provide poorer quality DNA for genetic
studies (Post et al. 1993; Reiss et al. 1995;
Dillon
et al. 1996)
or the age of samples provided.
While the idea that multiple introductions to
the United States have been proposed, alternate
introduction routes have never been substanti-
ated in literature. This study provides a glimpse
of some of the difficulties encountered working
with FST. Most notably, it would appear that the
low genetic variation detected with our COII
marker in this species does not equate to reduced
fitness or establishment capability.
Populations of nearly all species, social or other-
wise, exhibit at least some degree of genetic differ-
entiation among geographic locales (Ehrlich &
Raven 1969). Herein, we present two distinct COII
haplotypes of FST in the continental United States
(one based on our own samples evaluated, and a
second from Jenkins et al. (2002)). However, our
results appear to contradict the degree of variation
described by Jenkins et al. (2002). They describe 8
different COII haplotypes (maternal lineages)
from 14 geographic locations across the southeast
United States, Hawaii, and China. Applying the
COII marker to 60 geographic locations (Table 1)
we only identified 2 haplotypes—one in Japan, two
in Hawaii, the continental United States, and
China, respectively. Noting that many of the vari-
able sites in Jenkins et al. (2002) occur at positions
651 through 685 of their slightly larger COII am-
plicon (total size of the amplicon was 685), it is un-
clear where the discrepancies occurred. One possi-
bility may be due to sequence error that could only
be detected by comparison with greater taxon sam-
pling. Other possibilities may be due from im-
proper sequence alignment or mispriming of tem-
plate DNA during PCR. We elected to include all
taxa from Jenkins et al. (2002) into our sequence
dataset (COII lineages A through H), which may
have provided an advantage due to our larger
number of locations sampled. As with animal pop-
ulations, additional genetic structure normally is
to be expected over increasing spatial scales,
where populations can show additional differenti-
T
ABLE
2. H
APLOTYPE
VARIATION
AT
15
NUCLEOTIDE
SITES
FOR
NINE
C
OPTOTERMES
FORMOSANUS
HAPLOTYPES
.
Hap 8 11 19 32 33 46 176 211 222 297 333 427 643
a
653
a
662
a
1CGAATAAAATAGATA
2........GA.....
3............G..
4...........AG..
A
a
..G.....GA....C
D
a
........GAC....
F
a
.............A.
G
a
GT ....T......A.
H
a
...TATTT.......
a
Jenkins et al. (2002).
190
Florida Entomologist
89(2) June 2006
Fig. 4. Maximum Likelihood analysis
Coptotermes formosanus
lineages in North America.
Austin et al.:
Coptotermes formosanus
Genetics 191
ation due to spatial habitat structure and isolation
by distance (Avise 2004). However, our results
seem to refute this generalization for FST, a fact
probably attributed to its establishment ability in
fragmented urban ecosystems and their indirect
interactions with humans.
The preponderance of FST research appears to
support our findings. Haverty et al. (1990) found
no differences in qualitative cuticular hydrocar-
bon profiles among four FST populations in the
U.S. Korman & Pashley (1991) concluded that
populations from Florida and New Orleans are in
the same group and are very closely related to
each other, a finding also corroborated within the
present study (Fig. 3). Strong & Grace (1993) con-
cluded that low genetic and phenotypic variabil-
ity in introduced FST populations to Hawaii could
have been from a single event. Broughton &
Grace (1994) observed that only 9 of 16 different
restriction enzymes cut mtDNA zero or once.
Vargo et al. (2003) was unable to detect signifi-
cant isolation by distance among colonies at the
spatial scale studied (0.7-70 km) from 2 disjunct
populations of FST in Japan, nor from popula-
tions in New Orleans, LA and Oahu, HI. This sug-
gests a general lack of strong population viscosity
in introduced populations of FST. The finding also
seems to be contrary to Jenkins et al. (2002),
whose FST samples ranged in distance from 6-37
km in Atlanta, GA. Wang & Grace (2000), apply-
ing enzymatic polymorphisms, concluded that at
least two introductions to the United States have
occurred, but the second clade in their study
lacked sufficient samples from China to deter-
mine the origin of a second route.
More recently, the utility of mtDNA markers
for identifying where exotically introduced
Het-
erotermes
(Szalanski et al. 2004),
Nasutitermes
(Scheffrahn et al. 2004) and
Cryptotermes/Proc-
ryptotermes
(RHS, unpublished) to the United
States is being investigated. The principal caveat
with studies of this nature is that significant rep-
resentation of taxa is essential, particularly when
dealing with species of limited genetic variation
like FST. A secondary caveat is that tremendous
skill in identifying termites morphologically is es-
sential to ensure the validity of a genetic study
based on known, identified samples. Because FST
was likely misidentified when it was first ob-
served in the continental United States, little at-
tention was given, and subsequent populations
have developed over the years. This was one of the
reasons behind developing molecular diagnostics
for this species (Szalanski et al. 2004), and a need
to genetically review some species to corroborate
their original identifications (Scheffrahn et al.
2004). As population-level studies for FST from
various locations across the world continue to ac-
cumulate (see Vargo et al. 2003), perhaps a better
understanding of local factors which contribute to
the low genetic diversity observed in FST will be-
come more apparent. Given the 300 years of
known occurrence in Japan (Vargo 2003) and the
lack of genetic variation in China, it is unlikely
we will observe significant variation in this spe-
cies within the U.S. Random genetic drift is un-
likely to occur at a rate that we will detect any-
time soon. Perhaps more intuitively, we should
not assert our scientific prejudices about the na-
ture of reduced genetic variation in FST (causing
some reduction in fitness), or Isoptera in general,
until we more exhaustively investigate their ba-
sic biology and reproductive systems.
A
CKNOWLEDGMENT
We thank R. Davis, M. Merchant, G. Henderson,
K. Grace, J. Nixon, L. Yudin, J. Lopez, K. L. Mosg,
J. Chapman, S. Cabellero, J. Chase, B. McCullock,
O. Miyashita, E. Phillips, P. Ban, M. Weinberg, J. Stotts,
N.-Y. Su, E. Vargo, P. Fitzgerald, M. K. Rust, D. Mura-
vanda, J. Darlington, L. Ethridge, and J. Woodrow for
collecting termite samples. Research was supported in
part by the University of Arkansas, Arkansas Agricul-
tural Experiment Station, the University of Florida
Research Foundation, the Center for Urban and Struc-
tural Entomology, Texas A&M University, and a grant
from USDA-ARS Agreement No. 58-6435-3-0045.
R
EFERENCES
C
ITED
A
NONYMOUS
. 2004. Hsin-hui. The Columbia Encyclope-
dia, 6th ed. New York: Columbia University Press,
www.bartleby.com/65/. [15 September 2005].
A
PPEL
, A. G.,
AND
R. C. S
PONSLER
. 1989. Formosan ter-
mites now in Alabama. Highlights 36: 34.
A
TKINSON
, T. H., M. K. R
UST
,
AND
J. L. S
MITH
. 1993.
The Formosan subterranean termite,
Coptotermes
formosanus
Shiraki (Isoptera: Rhinotermitidae), es-
tablished in California. Pan-Pacific Entomol. 69:
111-113.
A
USTIN
, J. W., A. L. S
ZALANSKI
, P. U
VA
, A. B
AGNÈRES
,
AND A. KENCE. 2002. A comparative genetic analysis
of the subterranean termite genus Reticulitermes
(Isoptera: Rhinotermitidae). Ann. Entomol. Soc. Am.
95: 753-760.
AUSTIN, J. W., A. L. SZALANSKI, R. E. GOLD, AND B. T.
FOSTER. 2004a. Genetic variation and geographical
distribution of the subterranean termite genus Reti-
culitermes in Texas. Southwest Entomol. 29: 1-11.
AUSTIN, J. W., A. L. SZALANSKI, AND B. M. KARD. 2004b.
Genetic variation and distribution of the subterranean
termite genus Reticulitermes (Isoptera: Rhinotermiti-
dae) in Oklahoma. Florida Entomol. 87: 152-158.
AUSTIN, J. W., A. L. SZALANSKI, AND B. J. CABRERA.
2004c. A phylogenetic analysis of the subterranean
termite family Rhinotermitidae (Isoptera) using the
mitochondrial cytochrome oxidase (COII) gene. Ann.
Entomol. Soc. Amer. 97: 548-555.
AVISE, J. C. 2004. Molecular Markers, Natural History
and Evolution, 2nd ed., Chapman & Hall, NY. 511 pp.
BROUGHTON, R. E., AND J. K. GRACE. 1994. Lack of mito-
chondrial DNA variation in an introduced population
of the Formosan subterranean termite (Isoptera: Rhi-
notermitidae). Sociobiology. 24: 121-126.
CABRERA, B. J., P. G. KOEHLER, F. M. OI, R. H. SCHEF-
FRAHN, AND N.-Y. SU. 2000. The Formosan Subterra-
192 Florida Entomologist 89(2) June 2006
nean Termite. ENY-216, Florida Cooperative
Extension Service, IFAS, University of Florida. 7 pp.
CHAMBERS, D. M., P. A. ZUNGOLI, AND H. S. HILL, JR.
1988. Distribution and habitats of the Formosan
subterranean termite (Isoptera: Rhinotermitidae) in
South Carolina. J. Econ. Entomol. 81: 1611-1619.
CHHOTANI, O. B. 1985. Distribution and zoogeography
of the oriental termites of families Termopsidae,
Hodotermitidae, Stylotermitidae and Rhinotermiti-
dae. Z. Angew. Entomol. 100: 88-95.
COATON, W. G. H., AND J. L. SHEASBY. 1976. National
survey of the Isoptera of Southern Africa. II. The Ge-
nus Coptotermes Wasmann (Rhinotermitidae: Copto-
termitinae). Cimbebasia 3: 139-172.
DILLON, N., A. D. AUSTIN, AND E. BARTOWSKY. 1996.
Comparison of preservation techniques for DNA ex-
traction from hymenopterous insects. Insect Mol.
Biol. 5: 21-24.
EHRLICH, P. R., AND P. H. RAVEN. 1969. Differentiation
of populations. Science 165: 1228-1232.
FEI, H. X., AND G. HENDERSON. 2003. Comparative
study of incipient colony development in the Formo-
san subterranean termite, Coptotermes formosanus
Shiraki (Isoptera, Rhinotermitidae). Insect. Soc. 50:
226-233.
GAO, D.-R., B.-D. ZHU, AND X. WANG. 1982. Survey of
termites in the region of Jiangsu Province with de-
scriptions of two new species. Zool. Res. 3[suppl]:
137-144 (In Chinese with English abstract).
GLENN, G. 2002. Homeowners urged to be on lookout for
Formosan termites. Ag News, Agricultural Commu-
nications, Texas A&M University System, p. 30.
HAAGSMA, K., T. H. ATKINSON, M. K. RUST, D. KELLUM,
AND D. A. REIERSON. 1995. Formosan subterranean
termite established in California. Calif. Agric. 49:
30-33.
HALL, T. A. 1999. BioEdit: a user-friendly biological se-
quence alignment [ed.], and analysis program for Win-
dows 95/98/NT. Nucleic Acids Symp. Ser. 41: 95-98.
HAWTHORNE, K. T., P. A ZUNGOLI, E. P. BENSON, AND W.
C. BRIDGES. 2000. The termite (Isoptera) fauna of
South Carolina. J. Agricul. Urban Entomol. 17: 219-
229.
HAVERTY, M. I., B. L. THORNE, AND M. PAGE. 1990. Cu-
ticular hydrocarbons of four populations of Coptoter-
mes formosanus Shiraki in the United States:
Similarities and origins of introductions. J. Chem.
Ecol. 16: 1635-1647.
HAYASHI, Y., O. KITADE, AND J.-I. KOJIMA. 2003. Parthe-
nogenetic reproduction in neotenics of the subterra-
nean termite Reticulitermes speratus (Isoptera:
Rhinotermitidae). Entomol. Sci. 6: 253-257
HE, M.-Y., AND M. CHEN. 1981. Relationship between
geographic distribution of Coptotermes formosanus
Shriaki and the climate change in Sichuan province,
pp. 44-48 In Sichuan Termite Control and Research
Cooperation Team [ed.]. A Collection of Termite
Control Papers from Sichuan Province (1975-1980)
(In Chinese).
HOWELL, H. N., P. J. HAMAN, AND T. A. GRANOVSKY.
1987. The geographical distribution of the termite
genera Reticulitermes, Coptotermes, and Incisiter-
mes in Texas. Southwest. Entomol. 12: 119-125.
HOWELL, H. N., R. E. GOLD, AND G. J. GLENN. 2000.
Coptotermes distribution in Texas (Isoptera: Rhino-
termitidae). Sociobiology 37: 687-697.
HU, X. P., F. M. OI, AND T. G. SHELTON. 2001 Formosan
Subterranean Termites. ANR-1035. http://www.aces.
edu/department/extcomm/publications/anr/anr-1035/
anr-1035.html
HUSSENEDER, C., AND J. K. GRACE. 2000. What can DNA
fingerprinting, aggression test and morphometry con-
tribute to the identification of colonies of the Formo-
san subterranean termite? IRG/WP 00-10371, 8 pp.
HUSSENEDER, C., AND J. K. GRACE. 2001a. Evaluation of
DNA fingerprinting, aggression tests and morphom-
etry as tools for colony delineation of the Formosan
subterranean termite. J. Insect Behav. 14: 173-186.
HUSSENEDER, C., AND J. K. GRACE. 2001b. Similarity is
relative: hierarchy of genetic similarities in the For-
mosan subterranean termite (Isoptera: Rhinoter-
mitidae) in Hawaii. Environ. Entomol. 30: 262-266.
HUSSENEDER, C., E. L. VARGO, AND J. K. GRACE. 2002.
Multilocus DNA fingerprinting and microsatellite
genotyping: complementary molecular approaches to
investigating colony and population genetic structure
in subterranean termites. Sociobiology 40: 217-226.
JENKINS, T. M., R. E. DEAN, AND B. T. FORSCHLER. 2002.
DNA technology, interstate commerce, and the
likely origin of Formosan subterranean termite
(Isoptera: Rhinotermitidae) infestation in Atlanta,
Georgia. J. Econ. Entomol. 95: 381-389.
KISTNER, D. H. 1985. A new genus and species of termi-
tiophilous Aleocharinae from mainland China asso-
ciated with Coptotermes formosanus and its
zoogeographic significance (Coleoptera: Staphylin-
idae). Sociobiology 10: 93-104.
KIMURA, M. 1980. A simple method for estimating evo-
lutionary rate of base substitutions through compar-
ative study of nucleotide sequences. J. Molec. Evol.
16: 111-120.
KORMAN, A. K., AND D. P. PASHLEY. 1991. Genetic com-
parisons among U.S. populations of Formosan sub-
terranean termites. Sociobiology 19: 41-50.
LA FAGE, J. P. 1987. Practical considerations of the For-
mosan subterranean termite in Louisiana: a 30-
year-old problem, pp. 37-42 In M. Tamashiro and N.
Y. Su [eds.], Biology and Control of the Formosan
Subterranean Termite. Research and Extension Se-
ries 083. College of Tropical Agriculture and Human
Resources, University of Hawaii, Honolulu.
LENZ, M., AND R. A. BARRETT. 1982. Neotenic formation
in field colonies of Coptotermes lacteus (Froggatt) in
Australia, with comment on the roles of neotenics in
the genus Coptotermes (Isoptera: Rhinotermitidae).
Sociobiology 13: 59-66.
LIU, H., AND A. T. BECKENBACH. 1992. Evolution of the
mitochondrial cytochrome oxidase II gene among 10
orders of insects. Mol. Phylogenet. Evol. 41: 31-52.
LIM, P. 1997. Discovering Hong Kong’s Cultural Heri-
tage—The New Territories. Oxford University Press.
LIN, S.-Q. 1986. Formosan subterranean termite and its
control in China. Science and Technology of Termites
3(2): 1-8 (In Chinese with English abstract).
MESSENGER, M. T., AND A. J. MULLINS. 2005. New flight
distance recorded for Coptotermes formosanus
(Isoptera: Rhinotermitidae). Florida Entomol. Vol.
88: 99-100.
MIURA, T., K. MAEKAWA, O. KITADE, T. ABE, AND
T. MATSUMOTO. 1998. Phylogenetic relationships
among subfamilies in higher termites (Isoptera: Ter-
mitidae) based on mitochondrial COII gene se-
quences. Ann. Entomol. Soc. Am. 91: 515-523.
Mori, H. 1987. The Formosan subterranean termite in
Japan: distribution, damage, and current and poten-
tial control measures, pp. 23-26 In M. Tamashiro
Austin et al.: Coptotermes formosanus Genetics 193
and N.-Y. Su [ed.], Biology and Control of the Formo-
san Subterranean Termite. Research Extension Se-
ries 083. University of Hawaii, Honolulu.
POST, R. J., P. K. FLOOK, AND A. L. MILLEST. 1993.
Methods for the preservation of insects for DNA
studies. Biochem. Syst. Ecol. 21: 85-92.
REISS, R., D. SCHWERT, AND A. C. ASHWORTH. 1995.
Field preservation of Coleoptera for molecular ge-
netic studies. Environ. Entomol. 24: 716-719.
SCHEFFRAHN, R. H., AND N.-Y. SU. 1994. Keys to soldier
and winged adult termites (Isoptera) of Florida.
Florida Entomol. 77: 460-474.
SCHEFFRAHN, R. H., N.-Y SU, J. A. CHASE, AND B. T.
FORSCHLER. 2001. New termite records (Isoptera:
Kalotermitidae, Rhinotermitidae) from Georgia J.
Entomol. Sci 36: 109-113.
SCHEFFRAHN, R. H., J. KRECEK, B. MAHARJH, N.-Y. SU,
J. A. CHASE, J. R. MANGOLD, A. L. SZALANSKI, J. W.
AUSTIN, AND J. NIXON. 2004. Establishment of the Af-
rican termite, Coptotermes sjostedti (Isoptera: Rhino-
termitidae), on the island of Guadeloupe, French West
Indies. Ann. Entomol. Soc. Amer. 97: 872-876.
SCHEFFRAHN, R. H., J. KRECEK, A. L. SZALANSKI, AND J.
W. AUSTIN. 2004. Synonymy of the neotropical arbo-
real termites, Nasutitermes corniger and N. costalis
(Isoptera: Termitidae), with evidence from morphol-
ogy, genetics, and biogeography. Ann. Entomol. Soc.
Amer. 98: 273-281.
SIMON, C., F. FRATI, A. BECKENBACH, B. CRESPI, H. LIU,
AND P. FLOOK. 1994. Evolution, weighting, and phy-
logenetic utility of mitochondrial gene sequences and
a compilation of conserved polymerase chain reaction
primers. Ann. Entomol. Soc. Amer. 87: 651-701.
SPINK, W. T. 1967. The Formosan subterranean termite
in Louisiana. Louisiana State Univ. Circ. 89, 12 pp.
STRONG, K. L., AND J. K. GRACE. 1993. Low allozyme
variation in Formosan subterranean termite
(Isoptera: Rhinotermitidae) colonies in Hawaii. Pan-
Pacific Entomol. 69: 51-56.
SU, N.-Y., AND M. TAMASHIRO. 1987. An overview of the
Formosan subterranean termite in the world, pp. 3-
15 In M. Tamashiro and N.-Y. Su [eds.], Biology and
Control of the Formosan Subterranean Termite. Col-
lege of Trop. Agr. Human Resources, Univ. of Ha-
waii, Honolulu.
SU, N.-Y., AND R. H. SCHEFFRAHN. 1998. A review of
subterranean termite control practices and pros-
pects for integrated pest management programs. In-
tegrated Pest Management Reviews 3: 1- 13.
SU, N.-Y., AND R. H. SCHEFFRAHN. 2000. Termites as
pest of buildings, pp. 437-453 In T. Abe, D. E. Big-
nell, and M. Higashi [eds.], Termites: Evolution,
Sociality, Symbiosis, Ecology. Kluwer Academic
Publishers, Dordrecht, Netherlands.
SWOFFORD, D. L. 2001. PAUP*: Phylogenetic analysis
using parsimony (*and other methods), ver. 4.0b10.
Sinauer, Sunderland, MA.
SZALANSKI, A. L., D. S. SIKES, R. BISCHOF, AND M.
FRITZ. 2000. Population genetics and phylogenetics
of the endangered American burying beetle, Nicro-
phorus americanus (Coleoptera: Silphidae). Ann.
Entomol. Soc. America 93: 589-594.
SZALANSKI, A. L., R. H. SCHEFFRAHN, J. W. AUSTIN, J.
KRECEK, AND N.-Y. SU. 2004. Molecular phylogeny
and biogeography of Heterotermes (Isoptera: Rhino-
termitidae) in the West Indies Ann. Entomol. Soc.
Amer. 97: 556-566.
SZALANSKI, A. L., J. W. AUSTIN, R. H. SCHEFFRAHN, AND
M. T. MESSENGER. 2004. molecular diagnostics of the
Formosan subterranean termite (Isoptera: Rhinoter-
mitidae). Florida Entomol. 87: 145-151.
THOMPSON, J. D., D. G. HIGGINS, AND T. J. GIBSON.
1994. CLUSTAL W: improving the sensitivity of pro-
gressive multiples sequence alignments through se-
quence weighting, position-specific gap penalties
and weight matrix choice. Nucleic Acids Res. 22:
4673-4680.
TSUTSUI, N. D., A. V. SUAREZ, D. A. HOLWAY, AND T. J.
CASE. 2000. Reduced genetic variation and the suc-
cess of an invasive species. Proc. Nat’l Acad. Sci.
USA 97: 5948-5953.
TSUTSUI, N. D., A. V. SUAREZ, D. A. HOLWAY, AND T. J.
CASE. 2001. Relationships among native and intro-
duced populations of the Argentine ant (Linepi-
thema humile) and the source of introduced
populations. Mol. Ecol. 10: 2151-2161.
VARGO, E. L., AND G. HENDERSON. 2000. Identification
of polymorphic microsatellite loci in the Formosan
subterranean termite Coptotermes fomosanus
Shiraki. Mol. Ecol. 9: 1935-1938.
VARGO, E. L., C. HUSSENEDER, AND J. K. GRACE. 2003.
Colony and population genetic structure of the For-
mosan subterranean termite, Coptotermes formosa-
nus, in Japan. Mol. Ecol. 12: 2599-2608.
WANG, J. S., AND J. K. GRACE. 1999. Current status of
Coptotermes Wasmann (Isoptera: Rhinotermitidae)
in China, Japan, Australia and the American Pa-
cific. Sociobiology 33: 295-305.
WANG, J. S., AND J. K. GRACE. 2000. Genetic relation-
ship of Coptotermes formosanus (Isoptera: Rhinoter-
mitidae) populations from the United States and
China. Sociobiology 36: 7-19.
WANG, J., AND J. K. GRACE. 1995. Using a genetic
marker (MDH-1) to study genetic structure in colo-
nies of Coptotermes formosanus Shiraki (Isoptera:
Rhinotermitidae). Hawaii Agriculture: Positioning
for Growth. Conference Proceedings. CTAHR Univ.
Hawaii (Honolulu) 168-169.
WANG, C., J. POWELL, AND Y-Z. LIU. 2002. A literature
review of the biology and ecology of Coptotermes for-
mosanus (Isoptera: Rhinotermitidae) in China. So-
ciobiology 40: 343-364.
WELSH, F., AND M. RAO. 1996. A Borrowed Place: The
History of Hong Kong. Kodansha International.
... Recent phylogeographic studies using mitochondrial DNA (mtDNA) have also struggled to determine the origin of this species, as the variation of this marker is extremely low. These studies found either no variation between samples from Taiwan, China, and Japan 34,35 , or extremely low levels [36][37][38] . Even the complete mitochondrial genome reveals more than 99.9% similarity, with only a six nucleotide difference between three Japanese islands 39 . ...
... Several studies have also attempted to reconstruct the invasion history of C. formosanus. However, these studies have similarly suffered from the lack of genetic variation in the mtDNA present within native populations 36,[41][42][43] . As a result, no mtDNA variation was found in Hawaii 41 , and only 0-0.3% of variation was found on three mtDNA genes despite global sampling, with clades separated by a maximum of 3 bp differences 37 . ...
... As a result, no mtDNA variation was found in Hawaii 41 , and only 0-0.3% of variation was found on three mtDNA genes despite global sampling, with clades separated by a maximum of 3 bp differences 37 . Although the lack of mtDNA variation hampers the reconstruction of the invasion history of this species, several studies have found that introduced populations do belong to the same clade, suggesting that US populations of C. formosanus arise from at least two introduction events out of eastern Asia 36,[42][43][44][45] . Based on microsatellite markers, at least five different sources of introduction have been suggested 46 , with high similarity between the populations of Hawaii, Louisiana, and North Carolina 44 . ...
Article
Full-text available
Native to eastern Asia, the Formosan subterranean termite Coptotermes formosanus (Shiraki) is recognized as one of the 100 worst invasive pests in the world, with established populations in Japan, Hawaii and the southeastern United States. Despite its importance, the native source(s) of C. formosanus introductions and their invasive pathway out of Asia remain elusive. Using ~22,000 SNPs, we retraced the invasion history of this species through approximate Bayesian computation and assessed the consequences of the invasion on its genetic patterns and demography. We show a complex invasion history, where an initial introduction to Hawaii resulted from two distinct introduction events from eastern Asia and the Hong Kong region. The admixed Hawaiian population subsequently served as the source, through a bridgehead, for one introduction to the southeastern US. A separate introduction event from southcentral China subsequently occurred in Florida showing admixture with the first introduction. Overall, these findings further reinforce the pivotal role of bridgeheads in shaping species distributions in the Anthropocene and illustrate that the global distribution of C. formosanus has been shaped by multiple introductions out of China, which may have prevented and possibly reversed the loss of genetic diversity within its invasive range. Blumenfeld and Eyer et al. retrace the invasion history of the termite Coptotermes formosansus from eastern Asia to the US using approximate Bayesian computation. They find a complex invasion history, with multiple introductions originating from eastern Asia, as well as a bridgehead introduction originating from Hawaii, which appears to have mitigated the loss of genetic diversity within the invasive US range.
... High-throughput sequencing technologies, such as whole genome resequencing and reduced representation sequencing, provide huge numbers of molecular markers for genome-wide population genetic studies in nonmodel organisms (Ellegren, 2014). Genomewide markers, such as single nucleotide polymorphisms (SNPs), can be used for accurately estimating genome-wide genetic diversity both within individuals and at population levels and provide powerful tools to uncover population genetic structure and reconstruct invasion history (Austin et al., 2006;Baltazar-Soares et al., 2020;Le Moan et al., 2021;Liu et al., 2018). Moreover, genome scans allow detection of possible footprints of selection associated with local adaptation, albeit not without challenges (Haasl & Payseur, 2016). ...
Article
Anthropogenic biological invasions represent major concerns but enable us to investigate rapid evolutionary changes and adaptation to novel environments. The goldfish Carassius auratus with sexual diploids and unisexual triploids coexisting in natural waters, is one of the most widespread invasive fishes in Tibet, providing an ideal model to study evolutionary processes during invasion in different reproductive forms from the same vertebrate. Here, using whole‐genome resequencing data of 151 C. auratus individuals from invasive and native ranges, we found different patterns of genomic responses between diploid and triploid populations during their invasion of Tibet. For diploids, although invasive individuals derived from two different genetically distinct sources and had a relative higher diversity (π) at the population level, their individual genetic diversity (genome‐wide observed heterozygosity) was significantly lower (21.4%) than that of source individuals. Population structure analysis revealed that the invasive individuals formed a specific genetic cluster distinct from the source populations. Runs of homozygosity analysis showed low inbreeding only in invasive individuals, and only the invasive population experienced a recent decline in effective population size reflecting founder events. For triploids, however, invasive populations showed no loss of individual genetic diversity and no genetic differentiation relative to source populations. Regions of putative selective sweeps between invasive and source populations of diploids mainly involved genes associated with mannosidase activity and embryo development. Our results suggest invasive diploids deriving from distinct sources still lost individual genetic diversity resulting from recent inbreeding and founder events and selective sweeps, and invasive triploids experienced no change in genetic diversity owing to their reproduction mode of gynogenesis that precludes inbreeding and founder effects and may make them more powerful invaders.
... This is attributed to free trade of wood products. However, the reverse could be true, since species such as Cryptotermes brevis and C. formosanus, have reached the coast of Queensland, Australia, and Hawaii (USA) in the North Pacific Ocean and have invaded inland as well (Constantino, 2002;Austin et al., 2006;Jenkins et al., 2001). Among the 28 invasive species known to date a perusal of subcontinents or land mass from which the invasive species originated, Indo-Malayan region includes a maximum of seven species, indicating many endemic species have moved from this region to different parts of the world (Table 1). ...
Article
Full-text available
Termites are ubiquitously abundant in the tropics and subtropics. Globally 28 species are considered invasive among the 2937 species in nine families known. Among the invasive species, most are considered nuisance organisms to humans in urban areas, and a few have invaded natural forests. Generally, the invasive termites share three qualities: (i) they eat wood, (ii) make nests in wood, and (iii) they quickly generate secondary reproductives. These qualities are the most common in the Kalotermitidae and Rhinotermitidae (Blattodea: Isoptera), which enhance their opportunities for producing viable and reproductively capable individuals. Species of the Termitidae cannot produce secondary reproductives, and this is attributed as a reason for their lack of invasiveness. The 28 species recognized as strongly invasive have the potential to widen their geographical range from their present distribution locations. According to available data, 10 out of the 17 recognized invasive species have expanded their area of occurrence since 1969. Among the 28, three are known in India, although their exact distribution data in the Indian subcontinent, the damage they inflict, and consequent economic loss are yet to be worked out in detail. Climate change, intensifying urbanization, and globalization, acting either individually or in combination, are likely to exacerbate ecological and economic effects. Strict quarantine measures and appropriate treatment of every wood material imported are imperative. Efforts have been made to list the potential invasive termites in India based on imported-wood material. Approximately 70 species reported in the GenBank database for about 300 species known from India, emphasizing a dire need for accurate morphological and molecular determinations. Gene sequences of some of the Indian termite species submitted are incorrectly identified, as their presence and distribution in India is doubtful. Therefore, in this article, I discuss the importance of the combined and efficient use of morphological and molecular taxonomy in determining termites in India.
... However, the Mediterranean climate is atypical of the conditions of all other endemic or introduced localities of this species (Scheffrahn et al. 2020). Coptotermes formosanus is active in temperature ranges Previous studies attempted to infer invasion routes of C. formosanus in the United States, but the lack of mitochondrial genetic variation at the population level has obscured the precise inference of the source population and the routes of introduction (Austin et al. 2006, Husseneder et al. 2012, Blumenfeld et al. 2021. Even in the native populations of C. formosanus, there are only nine COII haplotypes (Fang et al. 2008). ...
Article
Full-text available
A new infestation of the Formosan subterranean termite, Coptotermes formosanus Shiraki (Blattodea: Rhinotermitidae), was discovered in Canyon Lake, Riverside County, California. We used three mitochondrial DNA (COI, COII, and 16S) and seven polymorphic microsatellite markers to characterize the genetic relationship of the colony with two other colonies that were collected in 1992 and 2018 in La Mesa, San Diego County. Maximum likelihood phylogeny of C. formosanus based on concatenated COI and COII sequences revealed that the two La Mesa populations (CA01 and CA02) and the Canyon Lake population (CA03) were from different maternal lineages. Based on the 14 COII haplotypes of C. formosanus found worldwide , CA01 and CA02 belonged to a haplotype widely distributed across the United States, while CA03 was grouped under a haplotype predominantly found in Asia. Microsatellite allele frequencies across all loci for both La Mesa populations were relatively similar, but significant genetic differences were found between CA02 and CA03 colonies (F ST = 0.24; Dest = 0.30; G″ ST = 0.55; P < 0.01).
... The Formosan subterranean termite, Coptotermes formosanus Shiraki (Blattodea: Rhinotermitidae), is an economically significant pest distributed in many warm temperate/subtropical regions of the world, including the United States of America, China, and Japan (Su, 2003;Austin et al., 2006;Scheffrahn et al., 2015;Chouvenc, Scheffrahn & Su, 2016). Suszkiw (2000) estimated that the annual repair and control cost of this pest was ∼1 billion dollars in the United States. ...
Article
Full-text available
Formosan subterranean termites, Coptotermes formosanus Shiraki, usually transport clay materials into tree hollows and bait stations. Our previous research showed that C. formosanus preferred to aggregate in the locations containing field-collected clay samples, but it was not clear whether this preference was influenced by clay types and/or moisture. In the present study, we conducted multiple-choice tests under low-moisture (25% moisture) or moderate-moisture (50% moisture) conditions to evaluate the aggregation and wood-feeding preferences of C. formosanus responding to hollow wooden cylinders (simulation of tree hollows) or baiting containers (simulation of bait stations) filled with different clay materials (bentonite , kaolin, chlorite, illite, or attapulgite), soil, or unfilled. Under low-moisture conditions, the majority of termites were found in the wooden cylinders or baiting containers filled with bentonite. Under moderate-moisture conditions, however, termites preferred to aggregate in wooden cylinders filled with chlorite or attapulgite; the percentages of termites that stayed in baiting containers filled with chlorite, attapulgite or soil were similar, which were significantly higher than those that filled with kaolin, illite, or unfilled. We then conducted no-choice tests to study the effect of clay materials on termites. Under low-moisture conditions, clay filled in the baiting containers significantly increased survivorship and body water percentage (an indicator of termite vigor) of termites, whereas no similar effect was detected under moderate-moisture conditions. This study demonstrated that both clay type and moisture affect termites' preference.
... Previous studies have attempted to determine the native range and introduction routes of C. formosanus using population genetics. However, multiple introduction routes are likely and global genetic variation among the populations is low (WANG & GRACE 2000, AUSTIN et al. 2006, LI et al. 2009, HUSSENEDER et al. 2012. The extent of the native range of C. formosanus is still uncertain among East Asian countries, such as Japan, China, and Taiwan. ...
Article
Full-text available
The Formosan subterranean termite, Coptotermes formosanus Shiraki, 1909 (Blattodea: Rhinotermitidae), is a well-known pest of wood structures. Its native range has been widely investigated for potential implications for pest control strategies. Termitophilous staphylinid species of the genera Japanophilus Maruyama & Iwata, 2002 and Sinophilus Kistner, 1985 found in nests of C. formosanus have been used to infer the native range of their host termite. Herein, we extend the range of these two genera to include Taiwan, the type locality of C. formosanus. Taiwanese specimens were identified as J. hojoi Maruyama & Iwata, 2002 and S. yukoae Maruyama & Iwata, 2002 based on morphological and molecular data. The first-instar larva of J. hojoi is described, the first known immature stage of the tribe Termitohospitini (Coleoptera: Staphylinidae: Aleocharinae).
... Following their introduction into the New World, Coptotermes formosanus Shiraki and Coptotermes gestroi (Wasmann) (Rhinotermitidae) became established and are considered invasive pests in subtropical Nearctic regions and the Neotropics, respectively (Constantino 2002, Scheffrahn andSu 2005). C. formosanus has been introduced to the United States on at least two separate occasions (Austin et al. 2006), and it was suggested that C. gestroi was also introduced from a limited number of events (Chouvenc et al. 2015). Owing to such limited introduction events, a bottleneck in genetic variability for both the termites and potential associates (Husseneder et al. 2002) may result in a 'symbiotic drift'. ...
Article
Full-text available
Termites and their nests are potential resources for a wide assemblage of taxa including nematodes. During dispersal flight events from termite colonies, co-occurring nematodes in the nest may have phoretic opportunities to use termite alates as transportation hosts. The two subterranean termite species Coptotermes gestroi (Wasmann) and Coptotermes formosanus Shiraki are both invasive and established in south Florida. Alates of both species (n = 245) were collected during dispersal flight events in 2015-2016 from six locations, of which 30 (12.2%) were associated with one or more species of nematodes. Species of Bunonema Jägerskiöld (Rhabditida: Bunonematidae), Halicephalobus Timm (Rhabditda: Panagrolaimidae), and Poikilolaimus regenfussi (Sudhaus) Sudhaus and Koch (Rhabditida: Rhabditidae) were isolated from 5.3, 4.9, and 0.4% of termite alates, respectively, and Bunonema and Halicephalobus were concomitant in 1.6% of alates. Additional C. formosanus alates were field-collected to establish laboratory colonies in sterilized rearing containers (SRC) to determine if alate-associated nematodes would colonize the newly established nest and/or brood. Among 1-yr-old termite colonies reared in SRCs, 26.9% of the colonies were positive for nematodes confirming that within-colony transmission of nematodes occurred. All three isolated nematode genera are free-living bacterivores capable of asexual reproduction. This suggests that these common co-occurring, termite-associated nematodes are opportunistic and facultative symbionts that receive increased opportunities of geographical dispersion through phoresy during termite dispersal flight events.
... The accuracy of criteria used to resolve distri butional status depends on how well the bio nomics of the insects in question are known (Turnbull 1980). Molecular genetics can be used to address long-standing questions about the origin of certain immigrant pests (Howard 1894), sometimes revealing the geographic sources of adventive insects and their invasion histories, including the detection of overlapping or sequential invasions (e.g., Austin et al. 2006, Carter et al. 2010, Xu et al. 2014). In some cases, the area of origin of a plant-feeding immigrant can be inferred from host plants in the insect's native area that show maximum resistance and, thus, a coevolved relationship with the herbi vore (Messing et al. 2009). ...
Chapter
Full-text available
Invasion biology now has a central role in biotic conservation, and invasive species are used as tools for biogeographic, ecological, and evolutionary research. This chapter discusses adventive insects that are immigrant or introduced, with an emphasis on North America. Examples deal mainly with human-assisted movement of insects between countries, even though intracountry changes in range are common among immigrant taxa (e.g., the glassy-winged sharpshooter (Homalodisca coagulata) and western corn rootworm (Diabrotica virgifera) within the United States). The chapter gives little attention to immigrants that arrive on their own by active flight, or by passive conveyance on convective air currents or strong winds associated with El Nino events, and discusses those that expand their ranges as the result of global climate change. An anthocorid bug (Anthocoris nemoralis) was introduced for biological control in western North America. The Canadian fauna also includes more than 300 species introduced for biological control.
... It is thought to have originated in China, but has spread to many areas around the world where it is a highly destructive pest of wood structures (Su & Tamashiro 1987). Recently, mitochondrial DNA sequencing ( Jenkins et al. 2002;Austin et al. 2006;Fang et al. 2008) has been used to study the genetic diversity of C. formosanus, mainly in China, America and Japan, but this information is insufficient for investigating the genetic diversity and detailed spatial structure of these populations. Microsatellite DNA loci as polymorphic genetic markers are necessary for elucidating the details of colony organization, population structure, and relationships among introduced and native populations (Ross 2001, Vargo et al. 2003. ...
Article
Full-text available
Seventeen polymorphic microsatellite DNA loci for Copototermes formo-sanus'wcre. isolated and characterized. Polymorphism of these loci was assessed in a sample of 32 unrelated C.formosanus individuals. An average of 4.6 alleles per locus (3-8 alleles) was detected. Observed and expected heterozygosities ranged from 0.2500 to 1.0000 and from 0.5591 to 0.8562, respectively. Six loci were found to have deviated from Hardy-Weinberg equilibrium in the sampled population after Bonferroni correction. No significant linkage disequilibrium was detected. These markers will be useful in population genetics, phylogenies and other relevant studies of C. formosanus.
Article
Full-text available
Workers of R. santonensis were used to determine the minimum number of termites required for colony survival and establishment. Survival was observed for initial termite numbers as low as ten under constant conditions at 25°C, 75% RH over 28 weeks. Results showed that an initial termite number of 250 gave the greatest population survival with 38 nymphs. Increasing initial termite numbers caused a decrease in the survival in the laboratory and an increase under field conditions. Survival decreased with time in the laboratory trials. There was no significant (P>0.05) interaction between density and substrate type and neither initial termite number nor substrate type and volume had a significant effect on the termite survival.
Article
Full-text available
A phylogenetic analysis of Heterotermes from 63 locations in the West Indies and associated mainland is presented based on the DNA sequence of a portion of the mitochondrial 16S rRNA gene. Maximum parsimony analysis of the aligned Heterotermes species and the outgroup taxa resulted in a consensus tree with five distinct West Indian groups. Morphological characters and geographical distribution supported the resulting clades, which were given the following taxonomic assignments: Heterotermes cardini (Bahamas and Cuba); Heterotermes sp. (Bonaire, FL; Grand Cayman; Grand Turk; Jamaica; and St. Barthelemy), Heterotermes convexinotatus (Antigua, Barbados, Curacao, Dominican Republic, Martinique, Puerto Rico, St. Kitts, St. Maarten, Venezuela, and Virgin Island), and Heterotermes tenuis (Lesser Antilles except Barbados and Martinique, Ecuador, and Suriname). The Florida Heterotermes sp. is a known nonendemic population, whereas those on Barbados, Grand Cayman, Grand Turk, Martinique, St. Barthelemy, and elsewhere may harbor or consist solely of nonendemic populations.
Article
Full-text available
A population of the Formosan subterranean termite, Coptotermes formosanus Shiraki, was discovered in La Mesa, San Diego County, in February 1992. This is the first instance of a non-native termite species being introduced and established in California. Due to the extremely destructive nature of this termite, a study was initiated to attempt to eradicate or control it using an insect growth regulator (hexaflumuron). Preliminary results suggest the product suppresses the population, but evaluation of this control is continuing. In the meantime, removal of excess wood reduces the food sources available to the termites and may help limit the growth and expansion of the colony.
Article
Full-text available
Results from two separate mark-recapture trials revealed that Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), alates are capable of flying nearly one kilometer across the Mississippi River and into the historic French Quarter. This is the first documented mark-recapture study with alates on this scale, and our results represent a new C. formosanus flight distance record.
Article
Eight species of termites are now recorded from South Carolina. Reticulitermes flavipes (Kollar) and R. virginicus (Banks) were the two most abundant subterranean species (Rhinotermitidae), each distributed throughout the state. Reticulitermes hageni (Banks) was distributed sporadically over the state, with records from six counties. Coptotermes formosanus Shiraki was found primarily in Charleston County, but new records extended the range to Beaufort, Dorchester, Berkeley, and Orangeburg Counties. Drywood termites (Kalotermitidae) were not encountered as frequently as subterranean species. Cryptotermes brevis (Walker) was recorded in seven counties throughout the state, Incisitermes snyderi (Light) was found in seven coastal counties and once in Pickens County, which is inland. Kalotermes approximatus (Snyder) was recorded primarily from natural habitats in 18 counties, and a western drywood species, Incisitermes minor (Hagen), was collected from Greenville and Beaufort Counties, representing a state record.
Article
The genus Coptotermes Wasmann is distributed throughout the eastern half of Texas. The first collection was made in 1956 in Pasadena, Harris County TX. During the past 44 years specimens have been collected from 13 other counties. Precipitation within this geographical area varies from an annual low of 594.4mm to an annual high of 1,480.8mm - a ratio of 2.4:1. However, the mean daily relative humidity (%RH) ranges from only a low of 56% to a high of 72% - a ratio of 1.2:1. Early collections of Coptotermes were restricted to coastal areas associated with deep water ports reinforcing the belief that these pest were introduced by intercontinental shipping. While shipping is a means of introduction, intrastate distribution seems to be associated with landscaping timbers, wooden mulch and construction materials. This pattern of establishment and distribution has been common in other areas of the U.S. with Coptotermes populations. Rainfall does not seem to be a limiting factor since Coptotermes is well established in areas with less than 600mm mean annual precipitation. The minimum %RH is 56% in the infested area of the state. As there are no quarantines concerning movement of materials infested with Coptotermes spp. within the state, %RH may be the defining factor limiting their distribution in Texas.