CACTUS-FEEDING INSECTS AND MITES 113 



the field station grounds at Uvalde, Texas; this is the only report of 

 prickly pears being attacked. 



Adults and larvae have been observed at various times from March 

 until October. The larvae feed externally and without any protective 

 covering on the younger segments. As a rule the insect is not common. 

 At sporadic intervals heavy infestations have been noticed on a few 

 or individual plants; under these circumstances the younger growth 

 is severely damaged. 



CHRYSOMELIDAE SPECIES UNDETERMINED 



In February 1924 at Humahuaca (altitude 9,000 feet) in the northern 

 province of Jujuy, Argentina, bluish-black chrysomelid larvae, about 

 one-half inch in length, were feeding externally or internally on the 

 younger segments of a small-jointed, mound-forming Tephrocactus, 

 either Opuntia russellii or a close relation. The larvae were solitary in 

 habit and moved from one segment to another. Attempts to rear the 

 adults were unsuccessful. 



Coleoptera: Anobiidae 



TRICORYNUS Waterhouse, spp. 



Adults of a small beetle of this genus were bred from prickly pear at 

 San Luis Potosi, Mexico, in July 1 928. The larvae tunnelled beneatli 

 the epidermis of the segments and pupated within the channels. Their 

 work resembled that of the lepidopterous miner Marmara opuntiella. 

 Another species of this genus has been found in Peru. In October 

 1936 creamy- white larvae were feeding in the fruit and flower heads of 

 Trichocereus sp. at Santa Eulalia in the Rimac Valley. From one to 

 several larvae inhabited the fruit, which were sometimes destroyed by 

 the attack. Adults emerged from late October to January. 



Coleoptera : Buprestidae 



Moderately large cream-colored larvae were located in November and 

 December 1936 feeding within the stems of Copiapoa cinerea at Taltal in 

 the drier northern sections of Chile. They formed fibrous cocoons within 

 the feeding cavities. In association with scavenging insects they caused 

 considerable damage. The adult was not bred, but R. C. Mundell 

 reported that skeletal remains inside plants represented "a medium- 

 sized buprestid with blackish elytra and shining green underparts." 



263-417—68 9 



