16 
moreover, the exuvium is plainly not at the center of the scale. The 
male of the San Jose scale is about two times as long as broad; broader 
at one end than at the other, with a large, dark exuvium, showing a 
central nipple. It is situated toward the small end of the scale. The 
male of the European fruit scale is not so elongate, and the exuvium 
is but little darker than the scale and nearer to the small end than in 
the San Jose scale. The male of Putnam's scale is as elongate as that 
of San Jose, but has an orange exuvium. The male of the cherry 
scale is in shape much like that of the San Jose scale, but the exuvium 
is of a brighter } T ellow, the scale usually being paler than the San Jose. 
« 4 
Fig. b.—Aspidiotus pcrniciosus: o, infested twig; b, view of infested bark magnified. (Howard and 
Marlatt.) 
In general the adult female of the San Jose scale may be distin- 
guished from its allies b} T the more circular scale, with yellow exuvium, 
when exposed, more centrally located, otherwise with dark nipple; the 
male by similar characteristics of exuvium and nipple. But the San 
Jose scale is most easily recognized by its immature scales, which are 
almost black, circular, and with a central nipple surrounded b^v one or 
two depressed circular rings. Such a character is not found in any 
other of the allied scales. 
