540 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



so that in 1893 it was discovered in orchards in Maryland and 

 Virginia. Since then .it has been spread on nursery trees to 

 practically every State. Investigations made by C. L. Marlatt 

 in 1901 showed that the insect is undoubtedly a native of cast- 

 central China, and was probably brought to this country on flower- 

 ing peach or some ornamental plant. 



Life History. The winter is passed as partly grown insects 

 under the scales, which begin to feed with the bursting of the 

 buds in spring. In the latter part of April tlic insects have become 

 full grown in the District of Columbia, and the males emerge and 

 fertilize the females. The male is a small, yellowish, two-winged 



fly, similar to Fig. 448. The males 

 emerge at night and arc so -small 

 they arc seldom seen unless reared. 

 About a month later the females 

 commence to give birth to live 

 young and continue to do so for 

 some six weeks. This species differs 

 from most scales in having no egg 

 stage, the eggs hatching in the body 

 of the female. The young insects 

 are very small, yellowish in color, 

 and resemble small mites. They 

 have six legs, a pair of antennae, 

 and a long thread-like beak through 

 which the food is sucked, as shown 

 in Fig. 394. The young insect moves about freely for from twelve 

 to thirty-six hours, then thrusts its beak into the bark or fruit, and 

 if a female does not move again. White, waxy filaments soon 

 exude from over the body, and in a couple of days the insect is 

 entirely covered by them, and as they mat down a scale is formed 

 which conceals it. This young scale is whitish with a prominent 

 nipple in the center. After the first molt, the females lose 

 eyes, legs, and antennae, for which they have no further use. 

 Nourished by the sap of the plant the insect develops rapidly and 

 is full grown in about a month. In the District of Columbia 



FIG. 391. Pear injured by the 

 San Jose scale showing the 

 discolored spots. 



