20 XEW YORK STATE MUSEUM 



terintj. The lialf grown catt'rpillars or larvae of certain moths hibernate in a 

 dormant condition in the sheltering grass ami in the spring resume feeding 

 and complete their growth. The partly grown bud moth in its cleverly con- 

 cealed silken case, sheltered by a protuberance on the twig, and the firmly 

 attached shelters of case bearers with their tiny occupants, are familiar exam- 

 ples of insects wintering in the caterpillar or larval stage. Many species, po.s- 

 sibly the majority, hibernate in the pupal stage, which, usually passed in 

 a secure and well hidden retreat, naturally affords much protection from the 

 elements, and as a consequence, hibernation in this form involves less risk 

 than wintering in some other. A large number of insects pass the winter as 

 adults in various sheltered places. E.xamples of these are many bugs, 

 beetles and even delicate moths and butterflies can withstand the e.xtreme 

 cold of our climate, and some forms are apparently able to survive the win- 

 ter in either the larval, pupal or adult condition. It is not the degree of 

 cold that is fatal to insects so much as repeated thawings and freezings or a 

 sudden change from one to the other. It is a well known fact that caterpil- 

 lars may be frozen stiff and revived, but they perish after this is repeated 

 several times. 



Parasitic and predaceous insects. These two groups of insects are 

 exceedingly important- in controlling insect outbreaks, and occasionally they 

 may be the principal agents in reducing the numbers of a serious insect 

 enemy. 



The studie.s of Dr L. (\ Howard' have thrown a flood of light on 

 the intricate relations which may exist between a notorious pest and its 

 insect enemies. The white marked tussock moth, Hemerocampa leu- 

 costigma Abb. & Sm., was exceedingl\- aljundant in Washington and the 

 opportunity was seized by Dr Howard to make the above mentioned study. 

 He succeeded in rearing from this insect 15 species of primary hymenop- 

 terous parasites and listed three others as probably having the same habits. 

 He also bred six primary dipterous parasites from this insect, making a total 

 of 21 and probably 24 species, which depend to a greater or less extent on 



' 1897 U. .S. Dep't Agric. Div. Ent. Tech. Ser. i. p. 1-57. 



