Species Phigalia plumogeraria - Walnut Spanworm Moth - Hodges#6661

6661

Walnut Spanworm (larva)

wingspan 32-45 mm, based on two Internet photos

Adult: female wingless, cannot fly; male antennae bipectinate; forewing gray with fine speckling and three inconspicuous dark gray lines; hindwing light brownish-gray with faint discal spot and two indistinct lines

Larva: gray twig mimic with small dorsal spine on abdominal segments 1-3 and 8

British Columbia to California, east to Utah and Wyoming

adults fly from January to April

larvae feed on leaves of Antelope Bitterbrush (Purshia tridentata), walnut, and willow

other Phigalia species are more prominently marked, and none occur west of Saskatchewan. The males can be separated from all other members of the genus by the antennae having fewer segments and much longer pectinations, by their larger wings, and by the forewings above being a unicolorous gray with almost straight cross lines

Moth Photographers Group (MPG)

Barcode of Life (BOLD)

live larva and adult images of male and female, plus foodplants (Jeremy Tatum, Butterflies and Moths of Southern Vancouver Island)

common name reference and foodplant (Washington State U.)

presence in California; list (U. of California at Berkeley)

presence in Wyoming; list search species 'plumogeraria' (Lepidopterists Society season summary (U. of Florida)

presence in Utah; list (Joel Johnson, Utah Lepidopterists Society)

distribution in Canada British Columbia only (CBIF)

A REVISION OF THE NEW WORLD BISTONINI, Rindge 1975 - A detailed description