Table 1 



Development of the ovaries of the autumnal race 

 of 20 — 30 days old С pleurostigma at various photoperiods. 



*) reared at room temperature. 

 **) weevils 34 days old. 

 ***) very little development. 



Table 2 



Effect of the photoperiod on weevils of the autumnal race, reared from May till August. 



These results indicate that there is no influence of hibernation on the effect 

 of the photoperiod. They also suggest that the artificially induced egg product- 

 ion can be continued for at least one generation. These experiments show 

 that the autumnal race of С pletirostigma is a short day insect. This fact is in 

 close accordance with its life cycle. The weevils emerge in the end of May 

 (photoperiod > 16 hours). They become active again in the end of August 

 (photoperiod < 16 hours). The point to be investigated now was лvhetheг or 

 not the short photoperiod induces the end of the aestivation period. 



To this purpose weevels reared at "long-day" were transferred after various 

 intervals to a short photoperiod. The results are shown in the next table. 



This experiment indicates that egg development rapidly starts again after 

 transferring the weevils to short photoperiods. In length of time, however, 

 the suppressing effect of long photoperiods may be broken and oogenesis may 



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