PREVIOUS WORK WITH INSECT PARASITES. 



37 



and that wherever it occurs there it has spread from a center of 

 imported American fruit trees. Finally, as a result of this extended 

 trip, the native home of the San Jose scale was found to be in northern 

 China in a region between the Tientsin-Peking Road and the Great 

 Wall, and its original host plant was found to be a little haw apple 

 which grows wild over the hills. Into that region no foreign intro- 

 ductions of fruit or fruit trees had ever been made, and the fruits 

 in the markets were all of the native sorts. Here in China was found 

 everywhere present a little ladybird, CMlocorus similis Rossi (fig. 9), 

 feeding in all stages upon the San Jose scale. One hundred and fifty 



Fig. 9.— The Asiatic ladybird {CMlocorus similis) ,an imported enemy of the San Jose scale: a, Second 

 larval stage; b, cast skin of same; c, full-grown larva; d, method of pupation, the pupa being retained 

 in the split larval skin; e, newly emerged adult, not yet colored; /, fully colored and perfect adult. 

 All enlarged to the same scale. (From Marlatt.) 



or two hundred specimens of the beetle were shipped by Mr. Marlatt 

 to Washington alive, but all but two perished during the winter. One 

 at least of the two survivors was an impregnated female, and began 

 laying eggs early in April. From this individual at least 200 eggs 

 were obtained, the work being done in breeding j ars. After some hun- 

 dred larvae had been hatched from these eggs the beetles were placed 

 on a large plum tree in the experimental orchard and protected by a 

 wire-screen cage covering the tree. The stock increased very rapidly, 

 and during August shipments to various eastern experiment stations 

 were begun, about 1,000 specimens being sent out. At the end of the 



