688 Bulletin 83. 



in alarming numbers on Damsons, Reine Claude de Bavay, 

 Quackenbos, and on Prunes. The Japanese varieties have not 

 yet been attacked, so far as we have learned. 



THE LIFE HISTORY OF THE INSECT. 



Its first appear a7ice and habits in the spring. — As previously 

 stated, the old shells of the female insects are to be found on the 

 trees at any time of the year, but as they no longer play any part 

 in the economy of the insect, the}- need not be considered in this 

 connection. It is only the small, flat, spindle-shaped, brown 

 scales that need attention early in the spring ; these are shown 

 natural size on the branch in figure i , and also on the portion of 

 board shown in figure 4, where they are scattered among the large 

 spiny skins of a Lady-bird larva. About April i , or even earlier, 

 these little scales begin to move about on the tree ; they are seek- 

 ing a suitable place to establish themselves. This they usually 

 do on the undersides of the smaller branches. Once established, 

 most of them probably never move from the spot. Each scale in- 

 serts its little beak or sucking organ into the bark, and for nearly 

 two months each of these minute pumps is kept constantly at 

 work drawing out the sap. 



Remarkable g^'owth of the scales in the spring. — As these little 

 scales have had their appetites whetted by over five months of 

 fasting, their little pumps seem to work with surprising vigor in 

 the spring. The result is that they increase in size remarkably 

 fast. In less than two months last spring, most of the little 

 scales, only i mm. (.04 of an inch) in length, grew to the size of 

 the scales shown on the front of this bulletin. Doubtless the 

 scales secrete considerable quantities of honey dew during this 

 period of rapid growth. 



Many of these little scales, however, do not grow into these 

 large conspicuous females. But after feeding for a short time, 

 their skin is cast off and it forms a thin, delicate, semi-transparent, 

 whitish, ribbed scale or shell over the pupae; beneath this cast 

 skin the male insect develops. The males are very delicate in 

 structure, and each is provided with two large whitish wings. At 



