11.4 ENTOMOLOGICAL SOCIETY 



and either braving the inclemencies of the top of Mount Wash 

 ington, as in the case of CEneis, or literally burrowing under any 

 shelter that may offer on the ground, even where the thermome 

 ter sinks to 40 and 50 degrees below zero, as in the case of 

 Vanessa antiopa ; or deliberately congregating and migrating 

 in vast bevies, as in the case of our Milkweed Butterfly, Anosia 

 plexippus. Where the winter is passed in the early larval 

 stages, it may be without special winter protection (Apatura, 

 etc.) or in a special hibernaculum (Limenitis, etc.). 



In the Heterocera the longest period of individual existence is 

 usually in the pupa condition, in which most of the species pass 

 the winter. Yet a number in different families are known to 

 hibernate in the adult state, probably a larger number in the egg 

 state, and a goodly proportion in the larva state. In some species 

 in warmer latitudes, as, for instance, in the notorious Leucania 

 unipuncta, the winter may be passed in any one of these states. 

 Again, also, species in the same family may be one-, or two-, or 

 many-brooded. In some of the Sphingidae and Noctuidae the 

 adult, especially in the monogoiiQutic forms, is endowed with 

 great vitality, and feeds and propagates during most of the grow 

 ing season, while in others the life of the adult is short and 

 ephemeral, this being more particularly true in the Bombycidae. 

 Departures from these normal conditions in the Order we might 

 expect to find in those species which, in the larva state, bore into 

 the trunks and roots of trees, or which feed on woollen goods, 

 dry vegetation or stored products, or which are sub-aquatic. For 

 here there is some reason to believe that under conditions of uni 

 form temperature and dryness the species may be prolonged in 

 1:he larva state, even though active, beyond a single year. Pro- 

 doxus decipiens in the stems of Yucca is a case in point, as the 

 larva has been known to live for five years and yet transform. 



HEMIPTERA. In the Heteropterous division of this Order we 

 have, as a rule, the longest period of individual life in the adult, 

 which is ordinarily the hibernating form. The Heteroptera ex 

 hibit great tenacity of life, especially in the adult condition ; yet 

 there are few records of experiments to indicate whether they 

 could be made to survive the single year which limits the exist 

 ence of the vast majority of the species. While so many hiber 

 nate as adults, yet a certain number pass the winter in the egg 

 state, and the two forms of hibernation are not infrequently met 

 with in the same family, or even genus. Aquatic forms, and 

 those which live under the bark of trees, or in other more or less 

 protected situations, may be found in all stages at almost all 

 seasons of the year, and, in default of experiment, it is difficult 

 to judge of the individual life period. That these insects are 



