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Aedes japonicus japonicus (Diptera: Culicidae)
arrives at the most easterly point in North America
Miles A. Fielden, Andrew C. Chaulk,
1
Kate Bassett, Yolanda F. Wiersma,
Mardon Erbland, Hugh Whitney, Thomas W. Chapman
Abstract—Aedes japonicus japonicus (Theobald) (Diptera: Culicidae), the Asian bush mosquito, is a
keen biter linked to the transmission to humans of a variety of diseases. It has moved significantly from
its historical Asian distribution, with its arrival in North America first noted in 1998 in New York and
New Jersey, United States of America. Here we report the presence of A.j.japonicus within our
collections of mosquitoes in the capital city of the easternmost province in Canada: St. John’s,
Newfoundland and Labrador, in 2013. This observation provides further evidence of this mosquito’s
ability to significantly expand its geographic range, potentially affecting connectivity between
subpopulations globally.
Résumé—Aedes japonicus japonicus (Theobald) (Diptera: Culicidae), le moustique asiatique Bush,
transmet aux humains une variété de maladies via ses piqûres. L’espèce a augmenté son aire de
distribution de façon significative, à partir d’une répartition historique en Asie jusqu’à son arrivée en
Amérique du Nord en 1998, à New York et à New Jersey, Les états-unis d'Amérique. Nous rapportons
ici la présence d'A.j.japonicus dans nos collections de moustiques dans la capitale provinciale la plus à
l’est au Canada, St Jean, Terre-Neuve, en 2013. Cette observation fournit une preuve supplémentaire
de la capacité de ce moustique d'élargir considérablement son aire de répartition, impactant
potentiellement la connectivité entre les sous-populations à l'échelle mondiale.
Aedes japonicus japonicus (Theobald) (Diptera:
Culicidae) is an aggressive biter (Kampen and
Werner 2014) with one study estimating that over
one third of its blood meals are taken from
humans (Molaei et al. 2009). In part due to its
willingness to bite humans, it is a competent
vector of disease for humans in both its native
(Takashima and Rosen 1989) and expanded range
(Turell et al. 2001). Aedes j. japonicus, native to
eastern Asia, was first documented in North
America in 1998 when specimens were collected
during a standard mosquito collection program in
New York and New Jersey, United States of
America (Peyton et al. 1999). Since its initial
introduction to North America, A.j.japonicus has
spread rapidly and is now found in over 30 states
in the United States of America (Kampen and
Werner 2014). In 2001, the first collections of this
species were made in Canada (southern Ontario
and Québec) during an annual West Nile virus
surveillance programme (Thielman and Hunter
2006). The mosquito species has since spread east
in Canada, through Québec and New Brunswick
by 2005 and Nova Scotia by 2008 (J. Ogden,
Department of Natural Resources, Nova Scotia,
Canada, personal communication).
While insular Newfoundland is geographically
isolated from mainland Canada, non-native
insects have been known to arrive through various
routes (e.g., drift migration via air currents),
making direct mosquito migrations possible
(Morris 1983). There is also potential for insect
transfer through travel and commerce (Reiter and
Sprenger 1987). Sampling of the mosquito fauna
of insular Newfoundland in 2005 (Hustin 2006)
and in 2011 (K.B., personal observation) did not
M.A. Fielden, A.C. Chaulk,
1
K. Bassett, Y.F. Wiersma, M. Erbland, T.W. Chapman, Department of Biol-
ogy, Memorial University, St. John’s, Newfoundland, Canada A1B 3X9
H. Whitney, Animal Health Division, Newfoundland and Labrador Department of Natural Resources, St. John’s,
Newfoundland, Canada
1
Corresponding author (e-mail: a.chaulk@mun.ca).
Subject editor: David McCorquodale
doi:10.4039/tce.2015.5
Received 19 June 2014. Accepted 6 November 2014.
Can. Entomol. 00:1–4 (2015) © 2015 Entomological Society of Canada
1
include A.j.japonicus within their collections.
However, in 2013 A.j.japonicus larvae did
appear within an array of containers that were
placed (with some experimental attractants, see
below) in search of another container breeder,
Culex pipiens Linnaeus (Diptera: Culicidae). The
appearance of A.j.japonicus was unanticipated
and, consequently, any life history details that can
be gleaned from this initial sampling are limited in
scope. However, A.j.japonicus was the most
abundant within our collections suggesting a rapid
spread after introduction that is characteristic of
this species (Kaufman and Fonseca 2014).
Twenty-seven containers (potential oviposition
sites) were deployed at residential or residential-
adjacent sites within the city of St. John’s,
Newfoundland and Labrador, Canada, non-
systematically covering an area of ~4 km
2
. Each
container was an 11.4 L translucent white plastic
bucket measuring 34 cm high with a radius of
10.3 cm. A volume of attractant solution was
added to each trap sufficient to result in a depth of
5 cm (~1.7 L). The attractant solutions that we
describe here were part of an experiment investi-
gating the use of an established attractant (grass:
Allan et al. 2005), a potential attractant (white
button mushrooms containing 1-octe-3-ol:
Berendsen et al. 2013; Mathew et al. 2013) and a
unique local ingredient, indeterminately aged
moose feces (collected from Salmonier Nature
Park, Newfoundland and Labrador). Fielden
(2014) contains a full description of this experi-
ment and outcomes. Attractant solutions that were
used within the area that lured A.j.japonicus
consisted of either mushrooms, moose feces, or a
mixture of the two aforementioned solutions and
grass clippings (collected from the St. John’s area)
blended with 5 L of tap water in each case. Of
particular note, during the period this manuscript
was in submission, we observed A. j. japonicus
adults emerging from a bucket containing rain-
water and cigarette butts. An identical comment
was made by Thielman and Hunter (2006). Both
notes highlight the enormous range of larval
habitats these mosquitoes are capable of using.
Traps were positioned in the shade beneath
trees to reduce evaporation rate of the attractant
solution. Also, increased shade cover is known
to increase pupal productivity (Vezzani and
Albicocco 2009). Aedes japonicus japonicus larvae
were collected from nine of the 27 containers.
Buckets were monitored weekly and when larvae
were detected they were collected and trans-
ferred to mosquito breeders (BioQuip, Rancho
Dominguez, California, United States of America)
that were kept in a laboratory with windows open,
such that the temperature approximated exterior
conditions.
Emerged adult mosquitoes were killed by
freezing, pinned and identified to species using
Darsie and Ward (2005). Identification was cor-
roborated and a voucher specimen was retained
by The National Identification Service of Agri-
culture and Agri-Food Canada (Ottawa, Ontario,
Canada). Additional specimens are available
in room SN-4113 at Memorial University of
Newfoundland. In total, 99 A.j.japonicus adult
females emerged from the collected larvae. The
eclosion of larvae in the laboratory occurred
between 13 August and 29 September 2013.
Additionally, a single adult specimen that was
naturally seeking a blood meal from a human was
Fig. 1. Photograph of Aedes japonicus japonicus
from the area of Devereaux Lane, Outer Cove,
Newfoundland and Labrador, Canada during the
evening of 24 September 2013. Mardon Erbland took
the photograph using a Canon EOS-1D Mark IV
camera equipped with a Canon MP-E 65 mm f/2.8
1–5× Macro Photo lens and Canon Macro Twin Lite
MT-24EX flash. A manual exposure (f/16, 1/160 sec,
ISO 250) and manual flash were used. The image
shows both the characteristic lyre shaped pattern of
gold coloured thoracic scales, and silvery-white scale
patches on the lateral thorax and abdomen indicative
of this species (Darsie and Ward 2005).
2 Can. Entomol. Vol. 00, 2015
© 2015 Entomological Society of Canada
photographed in Outer Cove, Newfoundland
and Labrador (~10 km north of St. John’s) on
24 September 2013 (Fig. 1). This photograph,
submitted by M.E. to the citizen science website
NLNature.com (which is administered by Y.F.W.),
clearly shows the lyre shaped pattern of gold
coloured thoracic scales, and silvery-white scale
patches on the lateral thorax and abdomen
indicative of this species (Darsie and Ward 2005).
The detection of a new species for the province
via NLNature.com is an example of how citizen
science may contribute to early detection of range
expansions (Catlin-Groves 2012).
Our identification of A.j.japonicus in insular
Newfoundland marks an ultimate eastern bound-
ary of the species in North America. The intro-
duction and establishment of A.j.japonicus has
the potential to alter mosquito community
dynamics by outcompeting congeneric and inter-
generic mosquito species (Kaufman and Fonseca
2014). Consequently, this mosquito also holds
the potential to indirectly alter the viral risks
of a region and, therefore, requires monitoring
(Kaufman and Fonseca 2014). Kaufman and
Fonseca (2014) projected a continued but slowed
expansion of A.j.japonicus into more northern
regions of North America. The observations made
here support a continued expansion; however, the
speed of the expansion requires more substantial
evaluation. A study focused on the geographic
connectivity of Newfoundland and Labrador
populations with populations in neighbouring and
distant regions is currently underway.
Acknowledgements
The authors thank the funding bodies that
enabled this work: Natural Sciences and Engineer-
ing Research Council of Canada; Animal Health
Division, Newfoundland and Labrador Department
of Natural Resources; Memorial University. They
are grateful for the help of H. E. Caravan, P.G.
Chaffey, P. J. Coates III, and S.C. Dufour.
References
Allan, S.A., Bernier, U.R., and Kline, D.L. 2005.
Evaluation of oviposition substrates and organic
infusions on collection of Culex in Florida. Journal
of the American Mosquito Control Association, 21:
268–273.
Berendsen, R.L., Kalkhove, S.I.C., Lugones, L.G.,
Baars, J.J.P., Wösten, H.A.B., and Bakker, P.A.H.M.
2013. Effects of the mushroom-volatile 1-octen-3-ol
on dry bubble disease. Applied Microbiology and
Biotechnology, 97: 5535–5543.
Catlin-Groves, C.L. 2012. The citizen science land-
scape: from volunteers to citizen sensors and
beyond. International Journal of Zoology, 23:
1–14.
Darsie, R.F. and Ward, R.A. 2005. Identification and
geographical distribution of the mosquitoes of North
America, North of Mexico. University Press of
Florida Gainesville, Florida, United States of
America.
Fielden, M.A. 2014. West Nile virus and the arboviral
mosquito community in St. John’s, Newfoundland
and Labrador. B.Sc. thesis. Department of Biology,
Memorial University of Newfoundland, St. John’s,
Newfoundland and Labrador, Canada.
Hustins, S. 2006. Mosquito ecology in relation to land-
use changes and potential West Nile virus in
Newfoundland. M.Sc. thesis. Department of Biology,
Memorial University of Newfoundland, St. John’s,
Newfoundland and Labrador, Canada.
Kampen, H. and Werner, D. 2014. Out of the bush: the
Asian bush mosquito Aedes japonicus japonicus
(Theobald, 1901) (Diptera, Culicidae) becomes
invasive. Parasites and Vectors, 7:7–59.
Kaufman, M.G. and Fonseca, D.M. 2014. Invasion
biology of Aedes japonicus japonicus (Diptera:
Culicidae). Annual Review of Entomology, 59:
31–49.
Mathew, N., Ayyanar, E., Shanmugavelu, S., and
Muthuswamy, K. 2013. Mosquito attractant blends
to trap host seeking Aedes aegypti. Parasitology
Research, 112: 1305–1312.
Molaei, G., Farajollahi, A., Scott, J.J., Gaugler, R., and
Andreadis, T.G. 2009. Human bloodfeeding by the
recently introduced mosquito, Aedes japonicus
japonicus, and public health implications. Journal
of the American Mosquito Control Association, 25:
210–214.
Morris, R.F. 1983. Introduced terrestrial insects.
In Biogeography and ecology of the island of
Newfoundland. Edited by G.R. South. Dr. W. Junk
Publishers, The Hague, The Netherlands. Pp. 551–591.
Peyton, E.L., Campbell, S.R., Candeletti, T.M.,
Romanowski, M., and Crans, W.J. 1999. Aedes
(Finlaya)japonicus japonicus (Theobald), a new
introduction into the United States. Journal of
the American Mosquito Control Association, 15:
238–241.
Reiter, P. and Sprenger, D. 1987. The used tire trade: a
mechanism for the worldwide dispersal of container
breeding mosquitoes. Journal of the American
Mosquito Control Association, 3: 494–501.
Takashima, I. and Rosen, L. 1989. Horizontal and
vertical transmission of Japanese encephalitis virus
by Aedes japonicus (Diptera: Culicidae). Journal of
Medical Entomology, 26: 454–458.
Fielden et al. 3
© 2015 Entomological Society of Canada
Thielman, A. and Hunter, F.F. 2006. Establishment of
Ochlerotatus japonicus (Diptera: Culicidae) in
Ontario, Canada. Journal of Medical Entomology,
43: 138–142.
Turell, M.J., O’Guinn, M.L., Dohm, D.J., and Jones, J.W.
2001. Vector competence of North American
mosquitoes (Diptera: Culicidae) for West Nile virus.
Journal of Medical Entomology, 38: 130–134.
Vezzani, D. and Albicócco, A.P. 2009. The effect of
shade on the container index and pupal productivity of
the mosquitoes Aedes aegypti and Culex pipiens
breedinginartificial containers. Medical and Veterinary
Entomology, 23:78–84.
4 Can. Entomol. Vol. 00, 2015
© 2015 Entomological Society of Canada