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Arthropods: Diptera CULICIDAE (Contact) Please
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underlined links to view: [Also See: <Culicidae Key>] Nematocera =
"long antennae."
Anophelinae-- Anopheles spp. The
wings are spotted with definite patches of scales. Their feeding position is at a 45-degree
angle with the surface.
The aquatic larvae feed horizontal with the water film due to short
terminal spiracles (See Photo). Members of the genus are the sole
vectors of malaria. They have long
palpi and the eggs are laid singly.
Culicinae -- Aedes, Coquillettidia, Culex spp. Haemagogus, Mansonia, Psorophora, Sabethes, The wings are not spotted and mostly entirely clear. The feeding position angle is primarily horizontal with the
surface. The aquatic larvae have
developed an elongated siphon and feed hanging down from the water surface at
an angle. Members of the genus
include the common pest mosquitoes, which carry many viruses such as Yellow
Fever, Dengue, Encephalomyelitis and the
Filarial Worm. They have short palpi and the eggs are laid in masses. There is
disagreement about the number of genera in the subfamily, but Service (2008)
listed 38 genera, assigning some to subgenus status. Of primary medical importance are Culex, Aedes,
Haemagogus, Sabethes and Mansonia, with Coquillettidia
and Psorophora of lesser
importance. Culex, Aedes
and Coquillettidia are found
both in tropical and temperate climates while Psorophora are found only in the Americas with a wide
distribution over many climates. Sabethes and Haemagogus are found only in Central and South America
with Mansonia occurs in
tropical portions only. Service
(2008) noted that members of the Aedes
genus are vectors of Yellow Fever
in Africa, while Aedes, Haemagogus and Sabethes are vectors of Yellow Fever
in South and Central America. Some Aedes vector Dengue Fever, and all Culicinae may vector other
arboviruses. Some Culex, Aedes
and Mansonia are also vectors
of Filariasis caused by Wuchereria bancrofti and Brugia malayi. Although some Psorophora
vector arboviruses, most species are mainly annoying pests. Coquillettdia
crassipes vectors Brugian Filariasis. Culex spp. Biology Many
different aquatic habitats are chosen for oviposition onto rafts that float
on the water. The Culex species tend to choose shallow
habitats such as ditches, ricefields and temporary puddles, with even small
containers and tree holes being adequate.
Culex quinquefasciatus,
the vector of Bancroftian Filariasis chooses polluted
aquatic habitats containing rotting organic debris. Service (2008) noted that the larvae of this species also occur
in ditches, blocked drains, septic tanks, etc. containing polluted water, and
that it has adapted well to urbanization.
The adults are especially active after sundown. Culex tritaeniorhynchus,
the vector of Japanese Encephalitis, chooses
ricefields, polluted fish ponds and puddles containing vegetation. Other species
of Culex, such as Cx. quinquefasciatus,
bite during nighttime and may rest indoors as well as outside of dwellings.
Many Aedes
species in warm climatic areas choose restricted containers to oviposit, such
as tree holes, small pools, tires, barrels, cans, etc. Service (2008) noted that Aedes aegypti breeds in
water-storage containers both inside and outside of dwellings. The larvae require uncontaminated water
for development. Aedes africanus, a vector of Yellow
Fever, breeds in tree holes and bamboo while Aedes bromeliae also a vector of Yellow
Fever, chooses leaf axils of banana, pineapple, etc. The vector of Dengue, Aedes albopictus, prefers
natural and container habitats.
Vectors of Filariasis, Aedes
polynesiensis and Ae.
pseudoscutellaris, develop in coconut shells or tree holes and
bamboo. Aedes togoi,
also a vector of Filariasis,
prefers pools of fresh water among rocks. Other Aedes species in colder climatic areas
prefer pools formed from melting snow and marshlands.
Aedes mosquitoes are able to complete
their development in only 7-12 days, depending on temperature. They are usually active in daytime and
rest outdoors. Haemagogus spp. Biology Mosquitoes of
the Haemagogus genus are restricted
to South and Central America. Their
eggs tolerate desiccation, and oviposition and larval development are
primarily in tree holes and bamboo, but also in rock pools, coconut shells
and occasionally in containers. But
they are typically forest dwellers.
The adults are active during the day feeding on simians in tree
tops. However, they may descend to
the ground during lumbering operations to attack humans. Several species, such as Haemagogus spegazzinii, Hg.
leucocelaenus and Hg.
janthinomys are vectors of Yellow Fever
(Service 2008). Sabethes spp. Biology Sabethes mosquitoes
are also restricted to South and Central America. Oviposition is in tree holes, bamboo and bromeliads, etc. They are also forest dwellers, which are
active during daytime primarily in tree canopies. However, they will also descend when forced to by logging
operations. Sabethes chloropterus
is a vector of Yellow Fever. Mansonia spp. Biology Most species
of Mansonia
occur in tropical climates, with only a few being found in temperate
regions. Oviposition is on the
undersurface of vegetation where the eggs are glued. The eggs can tolerate desiccation. The larvae develop in permanent water that
contains vegetation such as marshes and swamps. Irrigation canals with vegetation are also suitable. The larvae
and pupae remain attached to plants but will leave if disturbed, but they are
difficult to detect. Most adults are
active at night, with a few species also active during the day. Service (2008) reported that the medical
concern is for Mansonia vectors of Filariasis,
and rarely of some mild arboviruses. Coquillettidia
spp. Biology Mosquitoes of
the Coquillettidia
genus are of minor medical importance in the tropics but only occasionally in
temperate climates. Their eggs are
formed onto rafts that float like the Culex
species. The larvae are similar to Mansonia. Coquillettidia crassipes
is a vector of Filariasis. Psorophora spp. Biology Psorophora mosquitoes,
which range throughout the Americas, are also of minor medical
importance. Like Aedes their eggs tolerate
desiccation. Oviposition is in rice
fields and flooded pastures. There
are a few vectors of arboviruses, such as Venezuelan
Equine Encephalitis, and Yellow Fever. Their importance is mainly as vicious
biters (e.g. Psorophora ciliata, Ps. columbiae, Ps. cyanescens, Ps. ferox #1 & #2) = = = = = = = = = = = = = = = = = = = = Key References: <medvet.ref.htm> <Hexapoda> [Additional references may be found at: MELVYL Library ] Bock, G. R. & G.
Cardew. 1996. Olfaction in Mosquito-Host
Interactions. Chichester: Wiley
Publ., England Carpenter & Lacasse.
1955. Mosquitoes of North America. Clark, G. G.
1994. Prevention of tropical
diseases: status of new and emerging vector control strategies. Proc. Symp. Vector Control, Amer. J. Trop. Med. & Hyg. 50(6): 1-159. Clements, A. N. 1992.
The Biology of Mosquitoes. Vol. 1:
Development, Nutrition & Reproduction, Chapman & Hall, London. Curtis, C. F. 1989.
Appropriate Technology in Vector Control. CRC Press, Boca Raton, Florida. Foster, W. A. & E.
D. Walker. 2002. Mosquitoes (Culicidae). IN: Med. &
Veterinary Ent.. Acad. Press, Amsterdam.
pp. 203-62. Matheson, R. 1950. Medical Entomology. Comstock Publ. Co, Inc. 610 p. Service, M. 2008.
Medical Entomology For Students.
Cambridge Univ. Press. 289 p Legner, E. F. 1995.
Biological control of Diptera of medical and veterinary
importance. J. Vector Ecology 20(1):
59-120. Legner, E. F.. 2000.
Biological control of aquatic Diptera. p. 847-870.
Contributions to a Manual of Palaearctic Diptera, Vol. 1, Sci. Herald, Budapest. 978 p. Pates, H. & C. Curtis. 2005. Mosquito behavior and vector control. Ann. Rev. Ent. 50:
53-70. Spielman, A. &
M. d'Antonio. 2001. Mosquito: a Natural History of Our Most
Persistent and Deadly Foe. Faber
& Faber, London. |
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