CACTUS-FEEDING INSECTS AND MITES 87 



January and February 1 92 1 , larvae were feeding externally on segments 

 of Opuntia sulphur ea at Catamarca and Andalgala, western Argentina; 

 in confinement they readily attacked 0. ficus-indica. In December 

 1 924, larvae were devouring the corolla of the flowers and were eating 

 holes in young fruit of 0. sulphurea at Mendoza, western Argentina. 



LEPIDOPTERA SPECIES UNDETERMINED 



At La Guiara, Venezuela, three larvae were found in individual 

 cells in a segment of the prickly pear 0. schumanni. They were light 

 orange-red with a dark transverse band on each segment. The colour 

 and habits of the larvae suggest a relationship with the Mexican 

 gelechiid Metapleura potosi. 



In Argentina at Resistencia in December 1958, semi-looper larvae 

 belonging to the family Noctuidae were found feeding in Harrisia 

 martinii. This is the only record of this lepidopterous family on a cactus 

 species. 



COLEOPTERA 



The coleopterous insects of the Cactaceae comprise approximately 67 

 species. Hence this order is not greatly inferior to the Lepidoptera 

 in numerical importance. With few exceptions the cactus beetles are 

 included in the Cerambycidae and Curculionidae, and rouglily two- 

 thirds belong to the genera Moneilema (Cerambycidae) and Gerstaeckeria 

 (Curculionidae) . 



Not more than two species of Chrysomelidae are known to attack 

 cactus plants. This paucity of leaf-eating beetles in rather surprising. 

 As the succulent cladodes and stems of prickly pears and other cacti 

 should be particularly suited to the requirements of this family, one 

 might have expected that a group of cactus forms would have developed. 



Coleoptera: Cerambycidae 



The great bulk of the cactus longicorns are included in the genus 

 Moneilema Say with at least twenty-five species. The remaining five 

 species are divided between four difi'erent genera. With one exception 

 all the known cerambycid enemies are North American forms. 



ALCIDION Dejeaa 



This genus contains one cactus feeding species, which is indigenous 

 to South America. 



