24 6 Nebraska State Horlicullural Society. 



iag more slender and convex. As soon as the eggs are deposited bjr 

 the female she has performed her mission and dies, the dead insect 

 with its cottony mass still clinging in place, until some wind or rain 

 storm washes it away. Often they remain on the tree for a long 

 time, making it appear infested, when in point of fact the generation 

 had perpetrated all the damage of which it was capable when the egg 

 laying ceased. 



When the male larva has attained its full growth the propupa 

 forms within the larval skin, which in a few days is cast off and the 

 true pupal form assumed, which changes from a pale green to a dark 

 flesh color. The insect remains in this stage only a few days when the- 

 posterior end of the scale is raised by a pair of waxy filaments which 

 are secreted from near the end of the body, and the perfect winged male 

 emerges. In this stage the male insect takes no food whatever, having 

 no mouth parts and no mouth opening. It is equipped, however, with 

 a pair of eyes which are absent in the mature female. 



While this complex metamorphosis has been taking place in 

 the male insect, the females have undergone two moults and are of a 

 pale green color with a dark dorsal stripe extending the whole length 

 of the body marking the slight longitudinal ridge. In form they are 

 flatter than the males and somewhat broader, especially across the 

 posterior end. In the later part of August and early September the 

 two sexes mate and the males die. The females now gradually lose 

 their brighter colors, changing to a dark brown and becoming more 

 wrinkled. Before the leaves fall they migrate to the new growth of 

 twigs where they pierce the bark and feed as long as the sap flows, 

 become dormant at the approach of cold weather, and hibernate in 

 this position throughout the winter. 



As soon as spring opens, however, and the sap starts to flow 

 through the trees, the females which have not been subjected to the 

 attacks of parasites and have managed to withstand the vicissitudes 

 of winter begin to grow rapidly in accordance with the great develop- 

 ment of eggs within their body, and soon the cottony egg-sac referred 

 to above begins to form. This is gradually fllled with the light colored 

 orange-yellow eggs, which, as stated before, hatch out in June and 

 July. By this time the scale has assumed a position at a steep angle 

 with the twig to which it is attached, due to the enormous growth of 

 eggs beneath the body. 



By the above general description of the life history of. this insect 

 it will be seen that thre is but one generation each year, which, to 

 summarize briefly, occurs as follows: The young hatch from the eggs 

 in the early summer, the winged males emerge in the fall, mate with 

 the females and then die. The females migrate to the twigs where thoy 



