Evidence of seasonal eggs in Anopheles punctipennis (Diptera: Culicidae)

Anopheles punctipennis (Say), collected in October from resting sites in Illinois, deposited two morphologically distinct types of egg batches. One type was similar to the seasonal "winter" egg of Anopheles walkeri Theobald, with an extensive exochorion that covered all except the tip of the egg. Laboratory rearing of isofemale lines, under two different light-dark and temperature cycles, demonstrated that both types of eggs were intraspecific variants. F1 females from all "winter" egg batches deposited only normal eggs when reared under a 12:12 (L:D) cycle and at 25 degrees C. Most An. punctipennis reared under a 8:16 (L:D) cycle with variable temperature exhibited gonotrophic dissociation or accumulated fat body.