106 U.S. NATIONAL MUSEUM BULLETIN 25 6 



Gerstaeckeria clathrata (LeConte) 



This small species attacks the "tasajUlo" Opuntia leptocaulis, in Texas, 

 and has been recorded from other Gylindropuntias as far west as 

 southern Arizona. It is not uncommon around Uvalde, where adults 

 have been observed from March to November. 



Gerstaeckeria doddi Fisher 



The original description in 1925 was based on material from Uvalde, 

 Texas, in which vicinity the insect is prevalent. It occurs quite com- 

 monly through the Mexican States of Nuevo Leon, Tamaulipas, and 

 San Luis Potosf. The host plants are Platyopuntias. Adults have 

 been collected in every month from March to November. Around 

 Uvalde the beetles were present in considerable numbers in certain 

 areas of Opuntia lindheimeri during June, July, and August. 



The larvae live in cells near the base of the plants and in segments 

 in contact with the ground, even in detached portions. There would 

 appear to be at least three generations annually. Development is rapid 

 during the summer. Thus, adults collected in June had produced many 

 full grown larvae by the end of July, while in August larvae were full- 

 grown and were pupating 18 days after the parent beetles had been 

 placed in the cages. 



Gerstaeckeria porosa (LeConte) 



The distribution of this species is very extensive, from the lower Rio 

 Grande Valley through western and northwestern Texas, Colorado, 

 western Kansas, Nebraska, Wyoming, Idaho, Utah, Arizona, and New 

 Mexico. Specimens taken by the Board's entomologists in all these 

 States were given this identification. Frequently it occurs in abundance 

 in the Uvalde-Del Rio sector of Texas. In May 1 928 it was very common 

 throughout the Edwards Plateau country of central- western Texas. 



Adults have been taken in every month from March to September. 

 Immediately around Uvalde, G. porosa is found in company with G. 

 doddi; the latter species, however, seems to prefer the more sheltered 

 fields of Opuntia lindheimeri^ while G. porosa is more prevalent in the drier, 

 more exposed areas. West of Uvalde, G. doddi ceases to occur and 

 G. porosa is prevalent. 



Emergence occurs in spring from March to May. At Uvalde the 

 first beetles appear about the middle of March, and they are numerous 

 in April. Probably there are at least two generations annually. The 

 food plants comprise many species of prickly pear. The presence of the 

 insect is rendered conspicuous by the circular larval cells, measuring up 



