Epigenetic transmission of phase in the desert locust, Schistocerca gregaria: Determining the stage sensitive to crowding for the maternal determination of progeny characteristics

After solitarious Schistocerca gregaria female adults were exposed to crowded conditions for various lengths of time at different times during the reproductive cycle, they deposited eggs of various sizes. The larger the magnitude of the increase in egg size after the exposure, the smaller the proportion of green hatchlings characteristic of solitarious forms (and the larger the proportion of gregarized dark hatchlings); and there was a sigmoidal relationship between the two variables (R2 = 0.982; n = 435). This relationship may support a previous conclusion that progeny characteristics are pre-determined in the ovarioles, because egg size is determined in the ovarioles, not after ovulation.