CACTUS-FEEDING INSECTS AND MITES 125 



A. B. Gahan, of the U.S. Department of Agriculture, states (in litt.) 

 that while a few species of Torymus are phytophagous, most species 

 are bred from cecidomyid and cynipid galls. 



RILEYA Ashmead 

 Rtleya opimtiae Gahan 



This black eurytomid was described in 1936 from material reared from 

 the small fruit of the Cylindropuntia Opuntia leptocaulis at Uvalde, 

 Texas, in March and April 1928. The cecidomyid Asphondylia opuntiae 

 was bred from the same collection of fruit, but not necessarily from the 

 same individual fruit. 



Gahan has advised that there is very little exact information regarding 

 the life history and habits of species of Rileya, although most have been 

 definitely associated with Cecidomyiidae. However, many eurytomids 

 are phytophagous. It might be pointed out that during the Board's in- 

 vestigations Asphondylia was reared in very large numbers from fruit of 

 various Platyopuntias, and in no other case was Rileya bred in association 

 with the midge. 



HETEROPTERA 



Coreidae 



With the exception of the capsid Hesperolabops picta which is reported 

 to feed on other plants besides cacti, all the true cactus bugs belong 

 to the family Coreidae and are included in three genera, Chelinidea, 

 JVarnia, and Leptoglossus, each with several species. Chelinidea and 

 Narnia appear to be segregates restricted to the Cactaceae, but Lep- 

 toglossus contains many species that do not feed on cactus. 



In America and in Australia other Heteroptera, usually more or 

 less general feeders, are occasionally found in the adult stage on 

 prickly pears, but it is doubtful whether any of these insects complete 

 their life cycles on Opuntia. 



CHELINIDEA Uhler 



This genus contains four species, although it may be doubted whether 

 C. canyona is specifically distinct from C. tabulata. The three forms, 

 C. tabulata, canyona, and vittiger are primarily enemies of Platyopuntia, 

 while C. hunteri attacks Cylindropuntias. 



The life history and habits of the species are quite similar. Both 

 adults and larvae (or nymphs) feed by puncturing the joints, and 



