GEASSHOPPER OUTBREAK IN XEW MEXICO. 7 



desert sparrow hawk (Faleo sparverius phalaena) , nighthawk (Ohor- 

 deiles virginianus) , killdeer (Oxyechus vociferus), and quail (Coli- 

 nus virginianus). The results of further investigations in coopera- 

 tion with the Biological Survey on the destruction of grasshoppers 

 by birds in New Mexico will be published in another connection. 



Several species of lizards, which were very numerous in this local- 

 ity, fed voraciously upon the nymphs. Oftentimes lizards were noted 

 so bloated from grasshopper feeding that travel was accomplished 

 only with great difficulty. Horned toads were also heavy feeders 

 upon the immature grasshoppers. 



While the large droves were passing through the prairie-dog towns 

 these animals appeared to feed upon the grasshoppers in numbers. 



PARASITIC ENEMIES. 



A dipteron, Sarcophaga hellyi Aid., was found to be by far the 

 most important factor in the control of this species, and it was 

 equally efficient as a parasite upon both the nymphs and adults. 



Larviposition by the female of S. hellyi was continually noted 

 throughout the month of June. The female, as far as observed by 

 the writer, always chose individuals freshly molted or inactive, but 

 in an apparently healthy condition. 



During the latter part of June the grasshoppers were enormously 

 reduced in numbers from parasitism by S. hellyi. It was a simple 

 matter to count 15 or more dead grasshoppers to the square foot over 

 large areas. The grasshoppers died in such numbers in some lo- 

 calities that ranchers informed the writer that certain droves were 

 almost completely destroyed. 



On June 16 a female of S. hellyi was noted to deposit tiny mag- 

 gots on the dorsum of the thorax (pronotum) of a freshly molted 

 nymph. This nymph was captured as the fly finished the act. The 

 fly in question was then noted to rest upon the thorax of a second 

 nymph, where it commenced to larviposit. At this time, while in the 

 act of depositing a maggot, she was captured, and, although badly 

 crushed, the specimen was not so greatly disfigured but that com- 

 parison with previously reared specimens proved beyond a question 

 that all were identical. Careful comparison of this female taken in 

 the act of larviposition, with another female noted to be larvipositing 

 in the same manner, but not captured while in the act, proved again 

 that both were the same species. 



From the captured nymph above noted six specimens of S. hellyi 

 were reared. 



This was the only female which the writer was able to capture in 

 the act of depositing the tiny maggots, but it abundantly determined 

 the method of larviposition utilized by 8. hellyi in parasitizing I). 



