

1920] Herrick: Ilihernation of Insects 103 



extremes of temperatures except two short cold spells in January 

 when the ground was fairly well covered with snow. 



Another factor that must be taken into consideration in any 

 account of the activities of insect life during the season of 1919 

 is the character of the climatic conditions of the summer 

 following the winter of 1918-1919. 



The summer of 1919 was one of normal averages for the 

 months of July and August although there were extremes in 

 July largely because the thermometer went very low at one 

 period. May was nearly normal in temperature but the pre- 

 cipitation was above the normal while June was a month of 

 abnormally high temperatures with precipitation somewhat 

 below the normal and this may have favored the early increase 

 of insects. As a whole, the summer, from a human standpoint, 

 was pleasant and comfortable and a very favorable one for 

 crop production. 



The writer is well aware of the danger of making general- 

 izations regarding this phase of insect life. The factors are too 

 involved and there are too many conflicting conditions to make 

 possible any extended generaHzations. It is rather commonly 

 held, I think, that insects can better withstand winters with 

 steady low temperatures than seasons of sudden, wide, periodic 

 fluctuations of temperature. We shall probably find, when we 

 have sufficient accurate data, that insects can best withstand 

 winter or summer conditions of even or equable average tem- 

 peratures accompanied by certain optimum conditions of 

 humidity. 



There have been seasons when one or two insects, like the 

 army-worm. May-beetles, rosy apple aphid and green apple 

 aphid have been very abundant but as the author looks back 

 over the last half-dozen years he does not recall a season within 

 that period certainly when so many different species of insect 

 pests were so generally prevalent and destructive as during the 

 past summer. For example, the red-legged grasshopper, 

 Melanoplus femur-rubrum, was abundant and destructive over 

 a large part of the State. Say's bUster beetle, Pomphopcea sayi, 

 appeared in destructive numbers from Utica to near Buffalo. 

 The little black and red Hemipteron, Cosmopepla carnifex, a 

 weather barometer apparently, appeared in enormous numbers 

 in several localities. The wheat midge, Contarinia tritici, was 

 abundant and injurious over the whole State, while the green 



