136 ORDER HEMIPTERA 



which lasts two or three days, they may be distributed in 

 several ways. A good breeze might carry them some little 

 distance. They may be carried by birds. They may be 

 carried on pieces of plant on which they occur, which is the 

 means hx which most of the scale insects are distributed. 



Fig. 89. — Chionaftpis furfurus. Scurfy scale on apple. (Photo from Ohi< 

 Exp. Sta.) 



Oyster-shell scale is named from the shape of its scale. 

 It is a European species, but occurs as a widely djistrib- 

 uted species in this country and affects a number of host 

 plants, principally the apple. The adults mature in fall and 

 white eggs are deposited mider scales and survive the winter, 

 hatching early in June. The larvae then scatter and develop 

 during the summer. 



