Holcocephala calva

Robber Fly
Holcocephala calva

GenBank: 468736

Head: Very wide. Upper head dark brown. Back of had gray pile. Huge “goggle-like” bronze eyes. Head in profile very thin. Lower face has a few white hairs, no mustache (mystax).
Antenna: Brown, Y-shaped, base very short, last segment long.
Thorax: Dark brown pile with some vague grayish spots and streaks. Sides and underside of thorax whitish-gray. Segment 2 (scutellum) whitish-gray pile.
Wings: Entirely brownish, long, narrow. Halteres dark.
Legs: Dark brown with some white hair. Tips of segments darker. Front feet darker.
Abdomen: Brownish, lower margins of segments have a line of grayish pile. First 2 segments narrower than other. Female abdomen wider than male. Underside grayish.

Similar Species: Overall, H. calva is brown; H. abdominalis is yellow and red with shorter, wider wings, red legs and yellowish thorax.

Size: 8 to 9 mm.

Habitat: Forest edges and sand meadows. Cedar savanna on forested dunes in Lambton County.

Food: Smaller insects.

Flight Time: June to August

Life Cycle: Unknown

Comments: Essex County – Ojibway. Kent County – Rondeau Provincial Park. First recorded for Canada in 1999 from north Lambton County by Skevington.

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