Phantom Midge

are nearly transparent; these larvae are predaceous, capturing prey with their antennae. Adults do not bite.

MOSQUITOES Family Culicidae

Identification: Wings long, narrow, with scales along veins and wing margin. Distal part of wing with an unforked vein between 2 forked veins. Proboscis long. Ocelli absent.

Mosquitoes are common, widely distributed, and well-known insects. Males have very plumose antennae and do not bite; females, which have only a few short hairs on the antennae, do bite and are often serious pests. Mosquitoes serve as vectors of several important diseases: malaria, yellow fever, dengue, fila-riasis, and encephalitis; these diseases are chiefly tropical but some may occur in this country.

This family is divided into 3 subfamilies, Anophelinae, Culi-cinae, and Toxorhynchitinae. Anophelinae have palps long in both sexes (clubbed in cf) and the scutellum rounded; they rest with the body and proboscis in an almost straight line, at an angle to the substrate (some appear almost to "stand on their heads"). Culicinae have palps of the female short and those of the male usually long, and the scutellum 3-lobed; they rest with the proboscis bent down and the body more or less parallel to the substrate. Toxorhynchitinae are large mosquitoes, with the scutellum rounded and palps of the female short; the basal part of the proboscis is stout, the apical part is slender and de-curved. Anophelinae are represented in N. America by 1 genus, Anopheles, most species of which have patches of light and dark scales on the wings. Most of our mosquitoes (Culex, Aedes, Psorophora, and others) belong to the Culicinae. Toxorhynchitinae are represented by 1 genus, Toxorhynchites, and are not very common.

Mosquito larvae are aquatic and occur in ponds, pools, various containers of water, and in tree holes containing water. Larvae breathe at the surface; larvae of Toxorhynchitinae and Culicinae have a breathing tube at the posterior end of the body; larvae of Anopheles lack a breathing tube, and spend most of their time at the surface. Most larvae feed on organic debris; a few are predaceous. Pupae are aquatic and generally very active. Eggs are usually laid on surface of the water, either singly or in rafts. A few lay eggs near water, and the eggs hatch when flooded.

SOLITARY MIDGES Family Thaumaleidae Not illus.

Identification: Bare, reddish-yellow or brownish flies, about 8 mm. Venation reduced, and only 7 veins reach wing margin (R 2-branched, M unbranched). Ocelli absent. Antennae short, about as long as head, the 2 basal segments enlarged.

This group includes 5 rare N. American species, 2 in the East (Quebec to N. Carolina) and 3 in the West (British Columbia

and Idaho). Larvae occur on rocks in streams, and adults are usually found on vegetation near streams.

PUNKIES or BITING MIDGES Family Ceratopogonidae Identification: Minute flies, generally less than 3 mm. Ocelli absent. Radial branches prominent. Thickened part of C usually ends or % way to wing tip; M with 2 branches. Front tarsi not lengthened.

Many punkies bite man and may be very annoying. A few live as ectoparasites on the bodies of other insects and a few are predaceous. Larvae are mostly slender and snakelike, aquatic or semiaquatic.

MIDGES Family Chironomidae Identification: Ocelli absent. Thickened part of C ends near wing tip. M unbranched. Front tarsi usually lengthened. Wings long and narrow, c? antennae generally plumose.

Midges are very common insects, found almost everywhere and often in considerable numbers. Larvae of most species are aquatic, and many live in tubes constructed of debris; some larvae are red. Adults are generally soft-bodied, with long legs and antennae and a short proboscis; they do not bite. Midges frequently occur in large swarms, particularly near ponds and lakes.

BLACK FLIES Family Simuliidae Identification: Generally 4 mm. or less, stocky in build, and somewhat humpbacked. Antennae short. Ocelli absent. Wings broad at base, narrowing distally, anterior veins heavy and remaining veins weak. Usually gray.

Female black flies are vicious biters and are serious pests in many parts of the country. Larvae live in streams, often in large numbers, where they attach to objects in the water. Black flies are widely distributed; adults appear chiefly in late spring and early summer. In parts of the tropics these insects serve as the vector of onchocerciasis, a disease caused by a roundworm that sometimes also causes blindness.

WOOD GNATS Family Anisopodidae Identification: Mosquitolike in appearance, 4-6 mm. Ocelli present. Thickened section of C ends near wing tip. A discal cell and 5 posterior cells usually present (Anisopodinae); if a discal cell is lacking (Mycetobiinae) the base of M is lacking, the 2 basal cells coalesce, and Rs forks opposite the r-m cross vein.

The most common wood gnats (Anisopodinae) have faint spots on the wings, and usually occur in moist places where there is abundant vegetation; larvae occur in decaying materials. Wood gnats are often attracted to sap, and the larvae of some species live in fermenting sap.

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