Factors Influencing Embryonic Diapause in the Striped Ground Cricket, Allonemobius fasciatus (Orthoptera, Gryllidae)

Allonemobius fasciatus DEGEER lays eggs which avert diapause and hatch if incubated at a high temperature. The factors influencing the seasonal variation in the proportion of such eggs (fast-developing eggs) were studied. Female adults collected in summer were subjected to different photo-thermal conditions and their eggs were kept at 30℃ to determine the proportion of fast-developing individuals. The proportion of fast-developing eggs markedly increased when their female parents were held at 20℃ but not at 27℃. Photoperiod and senescence of adults appeared to have little or no influence on this phenomenon. Female adults under alternating temperature regimes having low average temperatures continued to produce eggs with a low incidence of fast-development. This suggests that female adults would require a continuous exposure to low temperature for a high production of fast-developing eggs.