Head: Face slightly shiny, whitish-gray on female, duller with more whitish pile on male. Female eyes wide apart, male’s closer but not touching. Whiskers (palpi) long, bright reddish-orange. Thick layer of yellowish-brown hair around entire back of head.
Antenna: Brownish-yellow, last segment lighter. 2nd joint very narrow. Joint 3 oblong, as long as 1 and 2 combined.
Thorax: Black. Segment 1 (scutum) base half covered with yellowish pile. Segment 2 (scutellum) has no bristles at tip of lower margin, but some erect bristles at each side.
Wings: Wings slightly tinted, base very dark and one small cross-wise spot at mid wing (cross vein r-m) dark. Calypteres usually dark brown.
Legs: Black with yellow toes and with the usual black bristles and hair. Female has wider front feet.
Abdomen: Shiny, deep bright reddish-brown (castaneous), with long bristles on lower half of abdomen sides. Many black bristles across lower edge of segment 2 and longer, thicker bristles across lower margin of segment 3. Bristles shorter, covering last segment and tip.
Similar Species: There are two others similar in Ontario with a red abdomen.
Archytas metallicus has long crossed (decussate) bristles at centre tip of thorax segment 2 (scutellum). These bristles point straight down to abdomen; J. adusta has none pointing downward. Abdominal segment 2 has only 2 bristles; many bristles on J. adusta.
Pararchytas decisus face is more hairy and yellowish, same color as hair layer around back of head; long crossed bristles at centre tip of thorax segment 2 (scutellum); wings darker with last two cross-vein lines before tip darkened (dm-cu and r4+5M).
Size: 12 to 15 mm long.
Habitat: Forest edges.
Food: Adults feed on flower pollen and nectar.
Flight Time: July to August
Life Cycle: Larva are parasites of the Silver-spotted Skipper Epargyreus clarus and Tiger Moths Halysidota harrisii and H. tessellaris. Possibly Giant Leopard Moth Hypercompe scribonia. Larvae attack Hypercompe species in Florida.
Comments: Essex County – Point Pelee (1), Leamington (1), LaSalle (1 on BugGuide). Very rare, northern range extension.
For information on synonyms, references and type specimens see next page