APPENDIX. 



367 



.as the second pair of legs and are not curved under, as formerly, but lie 

 ■::lose to the side of the body with the ends free. The first pair of legs are 

 held forward, reaching slightly beyond the eyes, the middle femora project- 

 ing somewhat beyond the margin of the abdomen. The hind legs are 

 Inclined backward and reach to the end of the body. The style is rounded 

 at tip, conical, and about as long as the posterior tibiae. 



From four to six days later, or from twentj'-four to twenty-six days from 

 birth, the males mature and back out from the rear end of their scales, 

 having previously, for a day or two, remained pi'actically developed but 

 resting under the scale. They seem to issue chiefly by night or in the 

 evening. 



The mature male ( Fig. 5 ) appears as a delicate two-winged fly-like insects 

 w'ith long feelers and a single anal style projecting from the end of the body ; 

 orange in color, with a faintly dusky shade on the prothorax. The head is 



Fig. 5— Adult male— greatly enlarged. (Original). 



darker than the rest of the body, the eyes are dark purple, and the antennae, 

 legs, and style are smoky. The wings are iridescent w^ith yellow and green, 

 very faintly clouded. 



Thirty days from birth the females are full grown and the embryonic 

 joung may be seen within their bodies, each enclosed in a delicate membrane. 

 At from thirty-three to forty days the larvae again begin to make their 

 appearance. 



The adult female, prior to the development of the young, measures one 

 millimeter in length and a little less in breadth, and is pale yellow with 

 transparent spots near the margin of the body (Fig. 6). 



The length of a generation is determined by the female, and as shown by 

 the above record, covers a period of from thirty-three to forty days. Suc- 

 cessive generations were followed carefully throughout the summer, and it 

 was found that at Washington four full generations are regularly developed, 

 with the possibility of a partial fifth generation. On a number of potted 

 trees a single overwintered female waS' leftj to each tree. After the full 



