Effects of Incubation Temperature and Maternal Photoperiodic Exposure on Hatching of the Eggs of the Greenbug, Schizaphis graminum (Homoptera: Aphididae)
Mittler, Thomas; Wipperfürth, Thomas
The eggs from crosses between sexuals of biotype C greenbugs, Schizaphis graminum (Rondani 1852), were incubated at different temperatures [T] for various periods during their pre-diapause, diapause, and post-diapause phases of development. Although some of the eggs hatched without being chilled below 16 C, hatching success was enhanced considerably by chilling the eggs at 1° or 6° C during the diapause phase. Diapause development required 40-50 days, and the median overall developmental period ranged from 60-80 d, at each of the T at which the eggs were chilled. Diapause could not be cancelled or curtailed by exposing the egg-producing sexual females to a short-night photoperiodic regime of LD 16:8 during most of their pre-natal development and throughout their post-natal life. The physiological and ecological implications of the results are discussed.