COCCIDAE FROM LOWER CALIFORNIA 97 



Diaspine Coccidae referable by the character of the tubular ducts to 

 the Diaspis series ; with more or less conspicuous paraphyses at the bases 

 of the lobes, the lateral lobes not bilobed; with the dorsal ducts few, not 

 arranged in definite transverse rows ; with the microducts very long and 

 slender ; with the circumgenital pores present or absent ; gland spines 

 few or lacking; the scale of the female more or less circular with the 

 exuviae subcentral, exuviation occurring by the pushing back of the ven- 

 tral derm; scale of the male somewhat elongate, with the exuvium at one 

 end, the texture as in the female. 



This definition, however, will exclude certain species now referred to 

 the genus and for which there appears to be no other available. There- 

 fore, rather than name a new genus in a group where practically none of 

 the existing genera are at all definitely limited, I prefer to extend the 

 definition of the genus to include these and certain other forms. Upon 

 this basis I understand the genus to include certain forms belonging to 

 the Diaspis series, in which the scale of the female is circular and that 

 of the male somewhat elongate but resembling that of the female in 

 texture ; the circumgenital pores either lacking or if present the pygidium 

 with paraphyses; the gland spines few or lacking; the dorsal ducts for 

 the most part few, although at times abundant, but never arranged in 

 sharply marked transverse rows, the lobes never bilobed ; the microducts 

 usually very long. 



As thus understood, the genus (including certain species here de- 

 scribed as new) contains ten species all of which are natives of south- 

 western United States and Mexico. It is in all probability a highly 

 artificial group, but withal less so than the majority of the so-called 

 genera of the Diaspinae. 



Pseudodiaspis larreae (Ckll.). 



Figs. 18, 19 



1897. Aspidiotus (Pseudodiaspis) larreae Ckll., Bulletin 6, t. s., Division of 

 Entomology, Department of Agriculture, p. 21. 



Type from Covillea glutinosa (= Larrea tridentata), Yuma, Ariz. 



Habit. "... Scale about 2 mm. diameter, flat, irregular, round 

 to suboval, dull white with a slightly creamy tint ; exuviae not visible in 

 the mature scale, but in younger scales the elongate-oval, pale straw- 

 colored first skin is exposed, sublateral or even quite lateral. . . . 

 Male scale small, elongate, mytiliform, white, with the elongate first 

 skin projecting at the small end like a Mytilaspis. . . ." 



Morphological characteristics. Adult female (Fig. 18) about 2 mm. 

 long, of the usual turbinate form, the cephalothorax quite heavily chitin- 



