CYPRESS BARK SCALE. 



17 



October and November. These mate and die in a few days. At this 

 time most of the females have cast their last skin and are about one- 

 half grown. 



The winter is passed as adult females, with no very definite period 

 of hibernation in the lower altitudes. In the Sierra Nevadas there 

 is a more definite period of hibernation and the generations are more 

 even. The female larva? become adults somewhat earlier in the fall. 

 When the cold weather strikes them, development becomes very slow. 

 In December females are found containing a few eggs. These de- 

 velop during the winter and early spring. 



Oviposition begins on the first warm days of spring and lasts 

 throughout the summer, beginning about April 1 and terminating 

 the latter part of September. In the fall the females, having com- 



Fig. 3. — Seasonal history diagram of the cypress bark scale. 



pleted oviposition. shrivel and die. By this time the young females 

 of the next generation are quite well developed, thus assuring the 

 presence of adult females during the whole year. 



The larva? issue from the eggs 30 or 40 minutes after deposition 

 and soon attach themselves. Larvae of the first instar may be found 

 from April to the middle of October, second-instar larva? from the 

 middle of May to the middle of November, and adult females from 

 about September 15 to the following September. Male prepupa? 

 and pupa? may be found in September. October, and November, and 

 adults in October. November, and December. A male pupa was 

 found hibernating in the Sierra Nevadas. A few scattering first 

 and second stage larva? may be found during the winter in the milder 

 climate near the coast. 



