BIO 7505, Biology: A Molecular Approach, LaboratoryMosquito Sexing and Identification

Sexing MosquitoesOnly female mosquitoes will be sampled for the heartworm studies, since heartworm is a blood borne disease and only females feed on blood. The difference between males and females can be distinquished fairly easily macroscopically. In females, the probiscus is a single tube that can be inserted through skin to draw blood. Note the female Culiseta longiareolata in figure A below. The arrow shows the single probiscus that is tube-like to facilitate the ingestion of a blood meal. Male mosquitoes (like the Ochlerotatus hendersoni in figure B below) feed on only plant nectar. They have a probiscus that is branched and feathery to increase the amount of nectar they can ingest (see arrow on figure B). Once the mosquitoes are collected, the males will be identified macroscopically by looking for the feathery probiscus and discarded. Females will be stored in a sealable container and placed in the freezer until they will be sorted by genus and species. It is critical that repeated freeze thaws be avoided!

http://en.wikipedia.org/wiki/Mosquitoe

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Figure AOchlerotatus hendersoni

http://bugguide.net/node/view/81410

Figure A Figure B

Morphology of an Adult Mosquitohttp://fmel.ifas.ufl.edu/key/anatomy/adult.shtml

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Suggested Order of Characteristics for Identification-

1. Male vs. female2. Size3. Mouthparts to id Anopheles vs. others4. Then look at Culiseta vs. Culex

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Species found in this Area

I. Anopheles :

There are approximately 460 recognized species: while over 100 can transmit human malaria, only 30–40 commonly transmit parasites of the genus Plasmodium, which cause malaria in humans in endemic areas. Anopheles gambiae is one of the best known, because of its predominant role in the transmission of the most dangerous malaria parasite species (to humans) – Plasmodium falciparum.

The name comes from the Greek αν, an, meaning not, and όφελος, óphelos, meaning profit, and translates to useless.[1]

Some species of Anopheles also can serve as the vectors for canine heartworm Dirofilari immitis, the filariasis-causing species Wuchereria bancrofti and Brugia malayi, and viruses such as one that causes O'nyong'nyong fever. There is an association of brain tumor incidence and malaria, suggesting that the Anopheles might transmit a virus or other agent that could cause a brain tumor.[2]

Mosquitoes in other genera (Ochlerotatus, Aedes, Culex) can also serve as vectors of disease agents, but not malaria.

Anopheles stephensi http://en.wikipedia.org/wiki/File:Anopheles_stephensi.jpeg

Anopheles General Features: 6

o Long legso 3 long projections: (2 palps) and 1 proboscis, and all are almost the same length

Anopheles quadrimaculatus Common in this area Very dark spots (patches) on wings but not on wing margins. Dark spots are actually clusters of

scales on the wing veins that darken the area (essentially no gold spots on wings) No white banding on palps

http://fmel.ifas.ufl.edu/key/anatomy/adult.shtml

Anopheles punctipennis Very common in this area Large gold spots (scale patches) on wings. Spots are actually clusters of gold scales on wing veins No white banding on palps

Anopheles walkeri Less common in this area Very dark spots (patches) on wings but not on wing margins

o Dark spots are actually clusters of scales on the wing veins that darken the area White banding on palps

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II. Culiseta :

Culiseta is a genus of mosquitoes. Most Culiseta are cold-adapted species which only occur in warmer climates during the colder parts of the year or at higher elevations where temperatures are low. The larvae of most species are found in ground waters such as bogs, marshes, ponds, streams, ditches, and rock-pools, but an African species occurs in tree-holes (phytotelma), a common eastern Palaearctic species occurs in water wells and rock-pools, and several Australian species occur underground. In our area, larvae prefer swampy areas with tree root crypts (water pools under root masses). Little is known about the blood-feeding habits of females. Most species feed on birds and mammals, but a few feed on reptiles. Several species attack domestic animals and occasionally humans.[2]

Culiseta is found throughout the world, except in South America.[2]

Culiseta General Features:o Very short palpso Generally darker body vs. Culexo Basal banding on abdominal segmentso “Armpit hairs” (tufts of bristles) that look like underarm eyelashes on underside of wings near

the base (don’t confuse loose, hanging, dark wing scales for the hair tufts)o Rounded abdomen at apex (end)

C. longiareolatahttp://en.wikipedia.org/wiki/Culiseta

Culiseta melanura Somewhat common in some parts of our area if their larval habitats are present Medium-sized mosquito No narrow banding on bases (“knees”) of leg segments (a.k.a. hind tarsomeres not banded with

whitish scales at bases)

Culiseta morsitans Somewhat common in some parts of our area if their larval habitats are present Larger species of mosquito Narrow banding on bases (“knees”) of leg segments (a.k.a. hind tarsomeres are banded with

whitish scales at bases)

III. Culex:

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Culex is a genus of mosquitoes, and is important in that several species serve as vectors of important diseases, such as West Nile virus, filariasis, Japanese encephalitis, St. Louis encephalitis and avian malaria.The adult mosquito can measure from 4–10 millimeters (0.16–0.39 in), and morphologically has the three body parts common to insects: head, thorax, and abdomen. As a fly, it has one pair of wings.Scientists at the University of California, Davis and the Swedish University of Agricultural Sciences (SLU), have identified nonanal as a compound that attracts Culex mosquitoes.[1][2][3] Nonanal acts synergistically with carbon dioxide.[4]

Male Culexhttp://en.wikipedia.org/wiki/Culex

Culex General Features:o Most are medium-sized, but some are very smallo Rounded abdomen at apexo No “arm pit hair” on underside of wings near baseo No banding on bases (“knees”) of leg segments (a.k.a. hind tarsomeres of these 3 species not

banded with whitish scales at bases)o Common in this area

Culex territanshttp://fmel.ifas.ufl.edu/key/anatomy/adult.shtml Very small species Apical banding on abdominal segments

Culex pipiens Basal banding on abdominal segments Lacks pair of white spots on the top of thorax. (Remember that the white spots are comprised of

scales and might rub off)

Culex restuans Basal banding on abdominal segments Pair of median white spots present on the top of thorax. (Remember that the white spots are

comprised of scales and might rub off)

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IV. Coquillettidia

http://fmel.ifas.ufl.edu/key/genus/coquillettidia_pert.shtml

Coquillettidia perturbans

“The cattail mosquito”

Coquillettidia General Features:o WNV and EEE vector?o Broad, petal-like “salt and pepper” colored scales on wings (vs. narrow, uniformly dark-

colored wing scales). (see next page)o Long legs with wide, white banding (see next page)o Proboscis with median wide band of whitish scales

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