Head: Rough textured, triangular, black (sometimes more yellowish in southern U.S.). Mouth yellowish to reddish. Whiskers (palpi) black. Very long tongue.
Antenna: Black, hairy. Segment 2 short.
Thorax: Orange-yellow with black on lower half, either as two small spots, or one large spot.
Wings (elytra): Rough, hairy, black; covering to abdomen tip. V-shaped area at center of base (scutellum) can be black or sometimes yellow.
Legs: Blackish-brown. Female front foot has fringe of hair.
Abdomen: Black to reddish-brown on underside. Male has tufts of hair on segments 3 to 5. Female none.
Size: 5 to 9 mm.
Habitat: Forest edges and meadows.
Food: Asteraceae flower like Bidens, Fleabane Erigeron, Boneset and Joe-Pye Weed Eupatorium, Yarrow, prefer Black-eyed Susan Rudbeckia
Flight Time: Late June to August in Ontario.
Life Cycle: Female lays about 25 pale yellow eggs on flower heads. Hatch on flowers in 4 to 5 days and stay clustered together. Larva called triungulins use their mandibles to hitch a ride on visiting bees. They drop off the bee at the nest and feed on bee eggs and stored food. These blister beetles have been found in nests of Leaf-cutter Bees Chelostoma, Megachile,
Anthidium and Long-horned or Digger Bees Melissodes species.
Comments: Essex County – Ojibway Prairies. Kent County – Rondeau Provincial Park.
For information on synonyms, references and type specimens see next page