12 



SCALE INSECTS. 



begin to produce young, and continue giving birth to 

 young for about six weeks. Then the over- wintered females 

 die. In the manner of bringing forth young, these difPer 

 from most insects. Generally tlie female insect deposits 

 eggs; these sooner or later hatch, and the young follow 

 their characteristic stages of growth. In this scale insect, 

 instead of laying eggs, the female gives birth to young di- 

 rectly. It can be readily seen that this places these insects 



xsx/" 



Fig. 2. San Jo8(' scale: a, young larva 

 — greatly enlarged : b, antenna of the 

 same — still more enlarged. (After 

 Howard, Cir. No. .3, 2d .ser., Div. Ent., 

 Dept. Agr.) 



among the most prolific forms of the order. In the devel- 

 opment from the egg stage time is consumed, and the un- 

 protected, sometimes conspicuous, eggs of insects are liable 

 to destruction, since they form food for birds and other in- 

 sects. These two important checks to increase are not met 

 with in the growth of this scale. It is an active force from 

 birth until its body is protected by a well-suited armor; 

 then it begins to withdraw the life fluid of the plant. 



Soon after birth the young insect comes from undt-r the 



