Compsobata univitta

Stilt-legged Fly
Compsobata univitta

 

Stilt-legged Fly Compsobata univitta female, June 12, 2011 Grand Falls New Brunswick.
Stilt-legged Fly Compsobata univitta female, June 12, 2011 Grand Falls New Brunswick.

Identification:
Head: Eyes reddish, face and top of head more orangish. Simple eyes (ocelli) black. White pile along inner margins of the eyes, continuing to top of head, and widening each side of the simple eyes.
Antenna: Yellowish-brown. Bristle (arista) black, tip feathered.
Thorax: Long and thin, not much wider than head; bristles at side edges and on lower margin. Colour of thorax varies from reddish-orange to reddish-brown with a black stripe down middle, widening at lower margin (V-shaped). Thorax side with varying amounts of white pile on lower half.
Wings: Narrow and long; slightly tinted yellowish-brown. Halteres pale yellow to whitish.
Legs: Long, pale yellowish-brown. Mid and hind thigh (femora) have brown ring just before tip. Mind and hind shins (tibiae) darker.
Abdomen: Color varies from reddish-brown to dark brown with golden lower margin on each segment. Abdomen long and thin, with an enlarged and rounded tip (bulbous) on male; underside has large claspers on segment 4. Female abdomen much wider, then constricted by a slightly narrower ovipositor. Both have the 4th segment on top side a lighter color.

Size: 6 to 7 mm.

Habitat: Prefers wet, shady areas, marshes, wet meadows, river banks.

Food: Adult food unknown. One report of dung.

Flight Time: Mid-May to August

Life Cycle: Eggs laid in rotting wood, rotten fruit and vegetation. Rest of life cycle unknown.

Comments: Essex County – Point Pelee, Ojibway Prairies. Kent County – Rondeau Provincial Park.

For information on synonyms, references and type specimens see next page

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