12 A CONTRIBUTION TO THE KNOWLEDGE OF 



purchasi (Fig. 3C) the ring contains many pores and but very few 

 spines. In /. seychellarum (specimens from Ceylon, determined by E. 

 E. Green) the pores are few and anteriorly the ring almost disappears. 



I have elsewhere recorded the presence of abdominal spiracles in the 

 females of certain species of this genus, but, as far as I am aware, they 

 have not been recorded in the male. In fact, I do not know that they 

 have been seen in the male of any Coccid. There are three pairs in the 

 male of /. rileyi, these being on the last three segments of the abdomen. 



Icerya rileyi Ckll. 

 Fig. 3B. 



Type host and locality. From Covillea and Prosopis, Mesilla Val- 

 ley, N. Mex. 



Specimens examined. From Covillea glutinosa near the Mesilla 

 Valley and Socorro, N. Mex., and from Prosopis. velutina near Ben- 

 son, Ariz. 



Habit. Dorsum with a few irregular tufts of secretion. Ovisac 

 quite long, more or less cylindrical, minutely ridged but not fluted, white 

 or slightly yellowish at the base. 



Morphological characteristics. Dorsum of the adult female rather 

 sparingly beset with spines and setae of various sizes, some short and 

 stout, others long and slender, these nowhere arranged in tufts. Mar- 

 gins with a series of long, slender setae arranged in twos or threes, the 

 groups on the abdomen being disposed one to each segment. Setae about 

 the anal opening rather small and stout, few. Pores throughout of but 

 one size, small, those of the ventral ring very numerous and accompanied 

 by a nearly equal number of short spines, those of the dorsum relatively 

 few, showing some tendency to form groups at intervals. Three pairs 

 of abdominal spiracles present, these at the posterior end of the abdomen. 

 Antennae, nine to ten-segmented. 



The adult male (specimens from Prosopis velutina, at Benson, 

 Ariz.) appears to be of the type common to the genus. It possesses three 

 pairs of abdominal spiracles, these on the last three segments. 



Notes : The specimens from Prosopis velutina differ somewhat from the 

 others in having the ovisac slightly yellowish at the base, agreeing in this respect 

 with the description of /. littoralis Ckll. Otherwise I am unable to detect any 

 difference between these and the specimens from the type host and locality. 



Cockerell has named the subgenus Proticerya with this species as the type, 

 basing this upon the nine-segmented antennae of the adult female. In some of 

 my specimens the antennae are nine-segmented on one side of the body and ten- 

 segmented on the other. As some of the species of Icerya that normally have 

 eleven-segmented antennae may in all probability at times vary to ten segments, it 

 hardly seems that this subgenus is worthy of recognition, at least on the basis of 

 this character alone. 



