586 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



appears, which migrates to other trees. They are about one-twelfth 

 inch long and have a wing expanse of one-quarter inch. They 



FIG. 442. Sexual female of the woolly apple-aphis, showing egg before and 

 after extrusion greatly enlarged. (After Alwood.) 



appear to be black, but the abdomen is really a dark yellowish 

 or rusty brown color when closely examined, and bears more or 

 less of the waxy secretion on the tip. Each of these winged 



FIG. 443. Sexual female and male of the woolly apple-aphis greatly enlarged. 



(After Alwood.) 



females give birth to from four to six wingless males and females, 

 which are deposited on the trunk of the tree. The sexes are 

 wingless, much smaller than the summer forms, and are without 



