The Senegalese grasshopper, Oedaleus senegalensis (Krauss, 1877) (Acrididae, Oedipodinae) survives the dry season under natural conditions as diapausing eggs. Females, reared under short photoperiod (10/24 hr), produced eggs which were mostly diapausing eggs, while those reared under long photoperiod (14/24 hr) laid essentially no diapausing ones (less than 3% of diapausing eggs). In addition, females submitted to a photoperiod of 10/24 hr, the percentage of diapausing eggs decreased with increasing female age.

The band-legged ground cricket group comprises a pair of very closely related species; Dianemobius fascipes occurs widely over tropical and subtropical regions of Southeast Asia, while D. nigrofasciatus is restricted to temperate regions. A similar situation is found in the lawn ground cricket group; the tropical/subtropical species D. taprobanensis is replaced by D. mikado in temperate regions. In both southern species, tropical strains were almost homodynamic, but they produced a few delayed eggs independently of photoperiod and a variable proportion of macropters in response to photoperiod; subtropical strains showed clearer responses. Both northern species controlled egg diapause, nymphal development and wing form by various photoperiodic responses. The two species groups showed parallel geographical profiles of size variation, and the adults and eggs were smaller in the southern than in the northern species. In the absence of strong climatic selection for larger growth rate, size increase in tropical regions would be counteracted by predation pressure. The optimal adult size thus seems to be smaller in tropical than in temperate regions, being determined by the geographically variable balance between counteracting selecting forces.

Eggs of the stoneflies Diura bicaudata and Arcynopteryx compacta, occurring in the middle-alpine vegetation belt, andDinocras cephalotes not recorded above the sub-alpine, reacted differently to the same temperatures. Those of D. bicaudata and A. compacta had a diapause during the winter. D. cephalotes eggs went into a stage of quiescence when the water temperature was lowered from 16° C to 8° C or below. They remained alive in this stage for about a year, but this quiescence could be broken at anay time when the eggs were transferred to 16 and 20° C.Freezing at -6° C followed by an increase in the water temperature led to a break in the diapause of A. compacta eggs after five months, but not of D. bicaudata eggs.Eggs of D. bicaudata began to hatch after nine months independently of previous freezing followed by an increase inwater temperature. Eggs of D. bicaudata held at a constant temperature of 1.5° C also began to hatch at the same timeas those kept at 8° or 16° C. However, the point of 50 % hatching was much delayed at 1.5° C.The egg diapause of A. compacta and D. bicaudata is an adaptation to areas with a severe climate typified by long cold winters and short summers. The quiescence period of D. cephalotes eggs enables the species to survive outside its normal distribution area.