Abstract
Under an assumption that the age of the population of female mosquito, Culex tritaeniorhynchus summorosus Dyar, captured in the pig baited traps will be older than that in the dry ice baited traps, the dimensional difference of the Ib follicular stage was compared between two populations. The follicular size of nulliparous and monoparous sac-like females, in the dilatation stages of a population in a pig baited trap was significantly larger than that of a population in a dry ice baited trap. However, the Ib follicular stage in each physiological age of the population in the pig baited trap was not significantly different in size between the specimens collected in the earlier and the latter half of the night, and such tendency was also recognized in the case of the population in the dry ice baited trap.
