Entomological Notes. 291 



from sudden changes they can endure the cold with safety, even a 

 number of degrees below zero. They have been found frozen in 

 the solid ice, and on being thawed out became as active as ever. 

 When not well sheltered a temperature of —12° or —15° generally 

 proves fatal to them. 



The time at which they make their first appearance in the 

 spring depends somewhat on the latitude and character of the 

 season. Hot, dry weather is very favorable to them and hastens 

 their development; and on the other hand, wet and cool weather 

 retards them and even keeps them back till late in the season. 

 Their first appearance, usually made in May, but occasionally in 

 April, seldom attracts attention, unless a special outlook is kept 

 up, as they are comparatively few in number, small in size and 

 are mainly on the wing at this time. Often the first that is known 

 of their presence is when the second brood is hatching out in 

 great numbers, and the work of destruction is well under way. 



In a very few days after leaving their winter quarters, the fe- 

 males commence to deposit their eggs, laying them not in large 

 clusters and all at one time, as is done by many of the insect 

 foes, but a lew at a time, and during a period of two or three 

 week?. It is to this fact that their destructiveness is largely due, 

 for it insures their perpetuation in large numbers. In the egg 

 and early larval stages, they are very tender, and much exposed 

 to injury. A severe storm, or even a very heavy shower, often 

 destroys them by myriads at this time, and if the eggs were all 

 deposited at once, the whole brood would occasionally be nearly 

 annihilated in this way. It is generally believed that the vitality 

 of the females is much greater than the males, and that the great 

 majority of those who survive the winter and the exposure of the 

 breeding season, are females. 



If the soil is loose and dry, and the weather warm and clear, 

 the female usually works her way down to the roots of the plant 

 and there deposits her eggs. When the soil is heavy or wet, and 

 the weather is unfavorable, the eggs are laid on the stalk, near or 

 even above the surface of the ground. Bright sunshine, a dry, sandy 

 soil and hot weather are the most favorable conditions to their devel- 

 opment ; and where these conditions obtain early in the season, it 



