THE COCCIDAE OF SOUTHWESTERN UNITED STATES 



47 



Morphological characteristics. Adult female about .5 mm. long, en- 

 tirely enclosed by the second exuvium, which is heavily chitinized both 

 dorsally and ventrally. Derm of the adult entirely membranous except for 

 the posterior end of the body, which is heavily chitinized (Fig. 22A). 

 From the dorsal aspect the pygidium (Fig. 22D) appears to be composed 



Fig. 22. Protodiaspis tridentata n. sp. : A, adult female ; B, pygidium of early 

 second stage; C, posterior end of first stage; D, pygidium of adult; E, 

 antenna of first stage; F, early second stage female. 



of three segments, the first two together occupying about half of its 

 length. First segment less heavily chitinized than the others and bearing 

 the anal opening. Third segment deeply divided into three lobes, the 

 middle lobe rounded at the tip, the others pointed. Middle lobe with a 

 single small spine on each side near the tip. On the ventral side the chi- 

 tinization appears to extend forward only to the posterior margin of the 

 first dorsal segment. The vaginal opening is considerably anterior to this 



