CACTUS-FEEDING INSECTS AND MITES 99 



Although variable in size, average examples are larger than M. armata, 

 and large females are very little smaller than big individuals of M. 

 gigas. 



The commonest member of the genus in New Mexico, its range 

 extends from such localities as Toyahvale, Balmorrhea, and El Paso in 

 west Texas, and northward through New Mexico as far as Colorado 

 Springs, Colorado; specimens have been taken at SafTord in south- 

 eastern Arizona. It is often very abundant in many valleys on the 

 eastern slopes of the Guadalupe and Sierra Blanca ranges in New 

 Mexico and around Trinidad and Walsenberg in the 0. imbricata 

 region of southern Colorado. 



The principal food plant is the Cylindropuntia 0. imbricata, but prickly 

 pears of the 0. engelmannii, and 0. phaeacantha types are attacked to an 

 appreciable degree. In the Uvalde cages the species was reared without 

 difficulty in 0. lindheimeri. The "tasajillo" 0. leptocaulis, a slender 

 Cylindropuntia, has been recorded as a host plant. 



There is an annual life cycle. The adults emerge in May and June, 

 and are prevalent in June and July. Under cage conditions at Uvalde, 

 beedes emerged in September-October from eggs laid in July, giving 

 a life cycle of 10 to 12 weeks, but 5t is doubtful whether an autumn 

 emergence occurs in the field. Oviposition takes place from May to 

 July, the eggs usually being fastened in crevices in the segments. The 

 beetles shelter beneath the fruit and growth of 0. imbricata during the 

 day and do not necessarily descend from the plants to seek cover after 

 their nocturnal activity. 



Moneilema gigas LeConte 



This fine shining black beetie with pronounced prothoracic spines 

 inhabits southern Arizona from the neighbourhood of Tucson south- 

 ward and west as far as the Quijotoa Mountains; the Board's most 

 northerly record is the Williams River north of Wickenburg. In mid- 

 summer the adults are common in many of the extensive Opuntia areas 

 near Tucson and on the lower slopes and valleys of mountain ranges 

 such as the Quinlan and Comobabi systems. 



It evinces a preference for Cylindropuntias, particularly for Opuntia 

 fulgida, on which the beedes have been collected in large numbers; as 

 many as 10 to 12 have been observed frequendy on small plants. The 

 Platyopuntias of the Tucson district, mainly 0. engelmannii, and several 

 related plants, are attacked and on occasion harbor adults in quantity. 

 Larvae have been found breeding in Ferocactus wislizenii, and Echino- 

 cereus polyacanthus. 



