Search methods for egg and larval stages of Puget & Fender’s blue butterflies (Icaricia icarioides blackmorei & I. i. fenderi) for purposes of experimental studies

Puget and Fender’s blues are subspecies of the widespread Boisduval’s Blue (Icaricia icarioides). Fender’s Blue (I. i. fenderi) is Federally Endangered, and is found in oak woodland and prairie habitat in the Willamette Valley of Oregon (Pyle 2002). Puget Blue (I. i. blackmorei) is a Washington State Candidate, and is found in prairies in the Puget Trough of Washington (Pyle 2002). Both butterflies have the same life cycle and feeding habits, and all life stages are visually similar. Eggs are laid on lupine leaves in May and June, during the butterfly’s flight period. Larvae hatch and feed on lupine leaves for one or two weeks, and enter diapause as second or third instar larvae. Larvae emerge from diapause in late February or March and feed for six to eight weeks. The mature, fourth instar larva pupates near the soil surface. Adults eclose in mid-May. Males are blue (Figure 1a) and females are brown (Figure 2a) above, and both sexes are light gray below with black markings (Figures 1b, 2b and 2c). Adults are surveyed using common methods for adult butterfly population assessments. Pupae are virtually impossible to survey in the wild, as they are small (around 10 mm) and hidden in duff and possibly underground.