10 



body, which gradually spreads in a more or less homogeneous layer 

 over the surface. This first molt sometimes occurs at Washington by 

 June 10, and a second molt by June 22. 



From young larvae which hatched on July 1, 1898, the first adult 

 males issued on August 18, the full grown male scales being readily 

 distinguished from the partly grown females by their narrower and 

 more convex form. On reaching full growth the male larva assumes 

 the propupal form within its scaly covering, and therefore without 

 strictly casting skin. In a few days the propupa casts off its skin and 

 assumes the true pupa form, which during its earlier stage is of a pale 

 green color, becoming dark flesh color at a later date. The true pupal 

 stage lasts only a few days, when the winged females appear, remaining 



a day or two below the scale 

 before coming forth. The 

 molted skins of the propupa 

 and the pupa are seldom seen 

 on the tree, as they are easily 

 dislodged by the wind. 



At the time when the males 

 emerge the females have un- 

 dergone two molts and are of 

 a pale green color, marked 

 with a brown dorsal stripe 

 for the whole length of the 

 body. The males copulate 

 with the females late in Au- 

 gust and early in September, 

 and early in October those 

 females which have escaped 

 the attacks of parasites and 

 other natural enemies begin 

 to take their station on the 

 nearby twigs. A change in 

 color from green to buff is 

 noted at this time and all are covered with a barely perceptible cover- 

 ing of waxy secretion. They are broadly oval and still quite flat. In 

 this condition the females remain through the winter, the males having 

 in the meantime died. 



With the opening of spring, however, the females begin to grow 

 rapidly, the eggs developing in great numbers, and by May, or as early 

 as April 15 at Washington, the formation of the egg sac begins. The 

 egg sac is composed of threads of tine wax. extruded from spinnerets 

 near the end of the body. These threads becorre matted together and 

 gradually form a large cushion under and behind the body of the 

 female. Into this mass as it grows are gradually extruded the oval, 

 light- colored, slightly reddish-yellow eggs, which, as above stated, hatch 

 during June and July and on into August, The growth of the egg sac 



Fig. 3.— Pulvinaria innumerabilis : female larva, third 

 stage, greatly enlarged, with leg below and antenna 

 above, still more enlarged (original). 



