Entomology. 399 



during a winter in which there are frequent sudden and extreme changes 

 01 temperature. 



In the case of some insects, at least, they will withstand very low 

 temperature without freezing. With the thermometer registering several 

 degrees below zero, I have pricked the thin shells of the little black eggs 

 of the common green apple aphis, which are laid in the fall on the bark 

 of the apple tree, w^here they are exposed to all the rigors of winter. 

 From every egg I thus pricked the juicy contents ran out as freely as on 

 a warm day in JSTovember. These facts show that it is possible for insects 

 to withstand the severe cold of winter or to hibernate, 



Sound Asleep. — Generally speaking, insects do not feed during the 

 winter; they truly hibernate. Of course, this statement applies only in 

 cold wintry latitudes and to outdoor insects. We will discuss the indoor 

 insects shortly. 



There are, as many understand, four different stages in the life- 

 cycle of many insects. First, the egg stage, which is the starting point 

 in the life of all insects; second, the caterpillar, grub, or maggot stage; 

 third, a quiescent pupa stage, when the insect makes itself over from a 

 caterpillar, grub, or maggot, into a butterfly, a beetle, or a fly ; fourth, the 

 adult insect. Hibernation among insects may occur in any one or more 

 of these four stages. Usually an insect passes each winter in a certain 

 stage, but some go into hibernation in two of these stages. 



Indoor Insects. — Every housewife is glad when the frosts of autumn 

 put an end to the house-fly warfare. As the house-fly's favorite breed- 

 ing place is horse manure, wiiich does not afford a congenial feeding 

 ground in winter, the pest is obliged to hibernate. Sharp eyes may find 

 some of the flies snugly tucked away in the cracks and crannies of our 

 houses and barns. Usually several of these wintering individuals will be 

 thawed out whenever a spare bedroom, public hall, or church is warmed. 

 When the whole house has to be warmed for the children's home-coming 

 for the holidays, some of last summer's house-flies vnW, doubtless, wake 

 up from their winter's nap in a window crevice and take a nibble at the 

 Christmas turkey. A few pestiferous mosquitoes may also be on hand, 

 as thev hibernate in similar situations. 



