Eobiana engelhardti subtropica (formerly Metrioptera hime) is wing-dimorphic. The long-winged (LW) morph was clearly induced by crowding during the nymphal stages. Short-winged (SW) females produced eggs more intensively in an earlier period than did LW females. This difference in egg production between the two wing morphs seems to be associated with different patterns of increase in body weight after adult emergence. The body weight of SW females rapidly increased and reached its peak at about the time when oviposition started. On the other hand, the increase in body weight of LW females was slow, although it continued even after the start of oviposition. These findings suggest that the SW morph is adapted to sedentary life and rapid reproduction and that the LW morph tends to migrate before or during reproduction. However, in both the morphs, reproductive traits (pre-oviposition period, egg-laying period, number of eggs laid, and longevity) were to some extent flexible and could be modified by photoperiodic conditions.

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Embryonic development in relation to life cycle adaptation was studied in the northern (Aomori, 40.6°N) and southern (Osaka, 34.9°N) strains of Eobiana engelhardti subtropica (formerly Metrioptera hime) (Orthoptera: Tettigoniidae). Eggs of the 2 strains showed similar thermal responses. At 20, 22.5, and 25°C, they developed to the mature embryonic stage without delay and entered an obligatory embryonic diapause (final diapause). At 27.5 and 30°C, on the other hand, embryonic development was markedly delayed. This retardation was more striking in the southern strain. Especially, summer diapause occurred in half-grown embryos at 30°C. A shift of temperature from 30°C to 20 or 25°C terminated summer diapause and the eggs started to develop. The final diapause is never terminated if kept at high temperatures. Final diapause requires an exposure to a cold temperature of 15°C or lower and the intensity is higher in the southern strain. Adults of the southern strain emerged in mid June or earlier and those of the northern in early-mid July. In outdoor experiments, the developmental rate decreased more conspicuously in the eggs laid earlier in the southern population. As a result, the eggs reached the final-diapause stage in autumn more synchronously than expected from the long egg-laying period. The decreased developmental rate and summer diapause appear to secure survival in the hot season and ensure reaching the embryonic diapause stage synchronously in autumn. The local variation in the final-diapause intensity seems to be related to the heat units in autumn which might otherwise cause untimely hatching.

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In three species of rice grasshoppers, Oxya japonica (Thunberg), O. chinensis formosana Shiraki and O. yezoensis Shiraki (Orthoptera: Catantopidae), most unfertilized eggs begin developing, but the viability of unfertilized eggs is much lower than that of fertilized eggs. The hatchability of unfertilized eggs is 17.8% in O. japonica, 10.4% in. chinensis formosana and 5.4% in O. yezoensis. The number of larvae developing to the adult stage is 9.7% in O. japonica, 6.3% in O. chinensis formosana and 1.4% in O. yezoensis. Thus, the rate of embryonic development, hatchability and adult emergence in parthenogenesis is highest in O. japonica, and lowest in O. yezoensis. All larvae and adults produced by parthenogenesis are female. The number of chromosomes in parthenogenetic embryos of all the three species is 24 and diploid.