18 BUTTERFLIES 



ever, has many exceptions, for one will often find closely 

 related species which differ in the stage of hibernation. 



As one would expect, the conditions of hibernation vary 

 greatly with the latitude. In the severe climate of the far 

 north the conditions are likely to be more uniform than 

 in the South where the milder climate permits greater va- 

 riation to the insect. In some cases where a butterfly 

 hibernates in only one stage in Canada it may pass the 

 winter in two or more stages in Alabama or Florida. 



In many other orders of insects the egg is a favorite stage 

 for hibernation. Even in the closely related moths it is 

 often chosen by many species, but comparatively few butter- 

 flies pass the winter in the egg stage. The little Bronze 

 Copper may serve as one example of this limited group. 



The conditions as to hibernation by the larvae of butter- 

 flies are very different from those of the egg. It has been 

 estimated that probably half of all our species pass the 

 winter in some stage of caterpillar growth. This varies all 

 the way from the newly hatched caterpillar which hiber- 

 nates without tasting food to the fully grown caterpillar 

 which hibernates full fed and changes to a chrysalis in 

 spring without eating anything at that time. A large pro- 

 portion, however, feed both in fall and spring, going 

 through the winter when approximately half grown. 



The Graylings and the Fritillaries are typical examples 

 of butterflies which hibernate as newly hatched larvae. 

 The eggs are laid in autumn upon or near the food plants 

 and the caterpillars gnaw their way out of the shells and 

 seek seclusion at once, finding such shelter as they may 

 in the materials on the soil surface. In spring they begin 

 to feed as soon as the weather permits and complete their 

 growth from then on. 



