68 



Blanch. (New Mexico) ; M. armatiim, Lee (Colo- 

 rado, Texas) ; i\J. obiusum, Lee (Utah) ; M. spoli- 

 atum, Horn (Lower California) ; M. forte, Lee; 

 31. subrugosum (?), Blanch. (Lower California) ; 

 M. ulkei, Horn (Texas) ; M. variolare, Thorns. 

 (Mexico); M. albopundatmn, Lee; M. crassum, 

 Lee (S.W.Texas). 



They are often gregarious and may be met 

 with in large numbers. Individuals may reach a 

 considerable size, an example of M. armatum col- 

 lected at Tucson, Arizona, measuring 32 mm. in 

 length and 23 mm. in breadth. 



The Commission saw no definite evidence of 

 the action of this genus of beetles during its 

 investigation in the cactus belt in the United 

 States (October, November, and early Decem- 

 ber), though individual adults of M. crassum 

 were taken near Sinton, Texas, on 0. lindhei- 

 meri, and of M. armatum, near Tucson, in Ari- 

 zona, under plants of 0. arbuscula, 0. spinosior, 

 and 0. fulgida, apparently overvidntering under 

 the latter circumstances. Fragments of a Monei- 

 lema were found under 0. missouriensis at 

 Wallace, in Kansas. Injuries resembling those 

 described and illustrated (C.I.) were seen in the 

 stems of 0. fulgida and allied Cylindropuntias, 

 but the larva whenever met with, which was 

 seldom, was foimd to be a Melitara (vide infra). 

 Being wingless and therefore endowed with 

 but indifferent means for extending its range, 

 its size and local prevalence would suggest that 

 it might prove highly destructive within a 

 circumscribed area. 



Prof. D. E. Merrill, of the New Mexico 

 Agricultural Station at Mesilla Park, kindly 

 supplied the following information regarding 

 the local species, M. armatum, which he found 

 to attack 0. arborescens, 0. tvliipplei, and allied 

 species of Cylindropuntias, but not, as far as he 

 had observed, any of the flat Opuntias. An 

 adult, under experiment, was found to feed on 

 any species of Opuntia, but under natural con- 

 ditions the Cylindropuntias constituted the food- 

 plants. The eggs (35 to 50) are laid in June 

 and July, each one being placed in a slit made 

 by the female in the upper edge of a joint, the 

 larvffi, on hatching, boring their way down into 

 the stem- joints. They commonly come out of the 

 plant near the ground, the stalk being frequently 

 killed as a result of the attack. The insect passes 

 through winter as a larva. The chrysalis period 

 is short, amounting apparently to some two or 

 three weeks. The adult breeds out during the 

 latter part of June, and will remain alive for 

 many months. On account of these facts, he 

 suggested that the adult would be the best stage 

 for transportation should it be decided to send 

 living specimens to Australia. 



Mr. C. H. Popenoe, of the Bureau of Ento- 

 mology, referred to the widespread destruction 

 of the common prickly-pear, 0. missouriensis, 

 caused by M. armatum near Wallace, in Eastern 

 Kansas. A visit was paid to the locality early 

 in December, but only a few fragments of the 

 insect were seen. Though a great deal of injury 

 had been caused to the Opuntia, at least a grea't 

 part of it was due to a species of moth, Melitara 

 dcniaia (vide infra). 



Mr. E. A. Schwarz, the Coleopterologist at 

 the National Museum, Washington, D.C., stated 

 that the genus Moneilerna was restricted to the 



Cactaceaj, and occurred in the United_ States in 

 every section of the dry cactus belt, its species 

 being important enemies of this group of plants. 

 Moneilerna spp. could be safely introduced into 

 any other country, though he did not know whether 

 they would prove to be effective there. The 

 stunting of the plant was a common result of 

 the attack. 



Mr. W. D. Hunter, the senior author of the 

 bulletin mentioned above (C.I., 1912), referred 

 to the fact that Moneilema in its adult condition 

 may act as a planter on account of its habit 

 of congregating on young joints, which are often 

 caused to fall to the ground, where they may take 

 root. 



Mr. J. D. Mitchell, who accompanied the 

 Commission during its tour in Southern Texas, 

 and who is also part author of the bulletin on 

 Cactus Insects, stated that Moneilema is not 

 sufficiently abundant in Texas to cause much 

 destruction of Opuntias there. 



No parasites of the genus are listed by 

 BJ^essrs. Hunter, Pratt, and Mitchell. 



Dr. ilerrill mentioned the occurrence at 

 iiesilla Park, New Mexico, of an unidentified 

 Cerambycid about two-thirds of the length of 

 Moneilema and attacking the same species of 

 Opuntia. 



CcenopcBus palmeri, Le Conte. 



Horn (1889, p. 162) bred out the adult from 

 Opuntia hernardina (Southern California), 

 within whose joints the larvse feed. It is not re- 

 ferred to in the text of the bulletin on Cactus 

 Iiisects, so that it may be assumed that it had 

 not come under official notice as a serious enemy. 

 l\Jr. Schwarz, however, when interviewed, stated 

 that this large longicorn breeds readily in the 

 joints and could be easily transported. He had 

 seen it at times in great numbers at Fort Grant, 

 Arizona. 



A second species of this genus, C. niger, 

 occurs at San Jose, Southern California, accord- 

 ing to information tendered by Mr. Schwarz, but 

 its food-plants were unknown to him. 



The Commission did not have an oppor- 

 tunity to investigate -the habits of either of these 

 beetles. 



Allorhina mutalilis, Gory. 



This searabeid is reported to attack com- 

 monly the friiits of Cereus in Arizona, but as it 

 is destructive to various other fruits (C.I., p. 35), 

 its introduction need not be considered. 



Disonycha varicornis, Horn. 



Both adults and larvae of this flea-beetle are 

 found in Texas on 0. leptocaulis and 0. 

 arborescens, but are not known to attack any of 

 the flat Opuntias. They are surface feeders, and 

 may occur in such numbers as to bill the host- 

 plant (C.L, p. 22, pi. 4).. 



As the greater number of Queensland priekly- 

 pears are flat Opuntias, and as 0. imbricata, an 

 ally of 0. arborescens, is very locally distributed 

 in that State, the introduction of Disonycha 

 would be of little value. 



