Identification: Exotic – native to Asia, spread to Europe and introduced to Pennsylvania in 2011. Now in Kentucky, Virginia and West Virginia. In Ontario in 2014.
Head: Black. Nose cone (palpi) extremely short and black. Long face.
Thorax: Dull black.
Wings: Dull black. Two forms – one entirely black. The other form has 4 bright yellow to white spots, 2 large squarish spots near the base of wings and 2 smaller spots at the tip wings.
Abdomen: Yellow-orange abdomen in both forms. Brighter in females than in males. Male abdomen sometimes has black spots or center stripes. Male tip orange to yellow, flaring out on each side past wing margin and usually visible.
Size: 6 mm long. 10 to 14 mm wingspan.
Habitat: Disturbed lands, meadows, roadsides, fields.
Food: Lamb’s Quarters Chenopodium album; Halberd-leaf Orache Atriplex patula
Flight Time: Early June to end of August.
Life Cycle: Mating takes place in the evening within hours of adults emerging. Females lay eggs on leaves of Lamb’s Quarters or Goosefoot. Larvae feed on leaf surface or flower buds under silken webs. (Not a leaf miner). Early instars are gregarious. Pupate on leaf top, under a heavily constructed silken web. Young larvae are green with a faint whitish stripe down center and at each side; each segment lower margin is white. Middle segment often with a large cream spot. Head has black dashes, and the typical V mark. Shield has a black spot on each side. Mature larvae are brown and cream. Center cream stripe is bordered with brown and side stripes are brown. Similar to Scythris limbella larva, but with a more solid, darker pattern. Mature larvae 15 mm long. Adults are day-flying and prolific – continuous generations every 5 weeks.
Comments: Not listed by Pohl (2018) for Canada or Ontario. In Essex County, larvae completely destroyed a 4 foot Lamb’s Quarters in about 6 weeks.
For information on synonyms, references and type specimens see next page