Abstract
The gonotrophic dissociation in Culex tritaeniorhynchus was commonly observed when mosquitose were exposed to out-door conditions in autumn through early winter, even if the larvae were maintained at high temperature and long day. The ratio of the gonotrophic dissociation in mosquitoes experienced out-door conditions from the pupal stage increased in accordance with the advance of the seasons. Mosquitoes transferred to the out-door after the emergence into adults showed neither the high ratio nor the seasonal elevation of the gonotrophic dissociation. Four types of the follicle development were designated by the observation : the complete absence of the follicle development (complete gonotrophic dissociation), the suppression of the follicle maturation (incomplete gonotrophic dissociation), the maturation of one or a few number of follicles (incomplete gonotrophic concordance) and the complete maturation of a number of follicles (complete gonotrophic concordance). The temperature at the time of pupal stage was not linearly correlated with the ratio of the gonotrophic dissociation indicating that other factors are relating on the appearence of the phenomenon. The photoperiod was considered to be the most regulative factor other than the temperature.
