CACTUS-FEEDING INSECTS AND MITES 93 



rugosipennis, and M. variolare occurred in considerable numbers at 

 scattered intervals in particular sections. 



The distribution of the species overlaps; tv^o or more may occur in 

 the same region, but generally one is the dominant form. Distribution 

 of Moneilema can be roughly divided into the following geographical 

 areas: 



Distribution Species 



Southern California spoliata 



Utah obtusa, appressa 



Colorado, Kansas, North atinulata, appressa, laevigata, crassa, nigriventns 



Texas 



South Texas ulkei, armata, appressa 



West Texas, eastern New armata, laevigata, appressa 



Mexico, Chihuahua, 



Coahuila 



Southern Arizona, south- gig(is, corrugans 



western New Mexico 



Sonora, Sinoloa pimalis, pollens 



Gulf Coast of Mexico ulkei, variolare, mundelli 



Central Mexico variolare, rugosipennis, aterrima, crassipes, blap- 



sides, mexicana, opuntiae, vittata 



Southern Mexico albopicta, ebinina, punctipennis 



There is much variation in size within any one form; very small ex- 

 amples are probably the result of an insufficient food supply in the 

 larval stage. The largest member of the genus is M. gigas, in which 

 large females attain a length of 1.5 inches. The closely related M. 

 pollens and M. pimalis are almost as large. Another group of related 

 forms, M. laevigata, M. armata, and M. rugosipennis, are a little smaller; 

 in fact, females of laevigata may approach the size of females of gigas. 

 In the small species, M. crassa, M. mexicana, M. nigriventris, M. annulata, 

 and a few others, undersized individuals may not exceed one-half inch 

 in length. 



The Texas form Af. w/A:^? was more fully studied than any, but several 

 other species have been given a good deal of attention. For certain 

 species, however, no information is available except the localities from 

 which adults were collected on Opuntia plants. 



Moneilema ulkei Horn 



This is a m.edium-sized beetle, the females rather dull black, the males 

 with white markings on the elytra. In Texas it has been found from 

 Brownsville, Beeville, and San Antonio west to the junction of the 

 Rio Grande and Pecos Rivers; it occurs in the foothills north of Uvalde, 

 but not on the western plateau nor in the coastal country around and 

 south of Galveston. In Mexico its range extends through the eastern 



