Abstract
In the first part of this work made with wild materials, it was pointed out that the state of hibernation in the Japanese Culex pipiens pallens Coquillett was more or less out of the control of direct temperatures (Hosoi, 1953) . The state, however, could be changed by exposing the insect to prolonged illumination, as was first reported by Tate and Vincent (1936), or by keeping the immature stages under a warmed condition, as Mer (1936) noticed the fact on egg production of Anopheles sacharovi. Further experiments were carried out with laboratory-bred mosquitoes to ascertain in what way and to what extent the light and temperature can alter the biting activity and the capacity for egg formation.
Techniques and the method of estimating the activity are in general not different from those described in the previous paper. Several colonies of mixed strains were started from wild larvae or adults, and maintained occasionally more than a year by inbreeding. For the feeding test female mosquitoes were used without insemination. Throughout the experiments they exhibited neither autogeny nor stenogamy.
