GRASSHOPPER OUTBREAK IN NEW MEXICO. 9 



below the soil surface, but very probably the maggots or puparia of 

 the hibernating fall generation enter the soil to a much greater depth. 



Sarcophaga hellyi is a plural-brooded species, several generations 

 occurring during the season. At least two and probably three gen- 

 erations went through to maturity as parasites of D. longipennis 

 from early May to the middle of July. 



The grasshoppers will die from the effects of the parasitism while 

 in the act of feeding, and thus they are found hanging to a grass 

 stem, the mandibles firmly attached, in their last dying grasp. The 

 dead grasshoppers lying on the ground may be full of crawling 

 maggots still feeding or endeavoring to issue from their host to enter 

 the soil. When the maggots have emerged from the host only the 

 shell of the grasshopper remains. 



Methods of larviposition much similar to those noted by the writer 

 have been recorded by Kunkel d'Herculais on Sarcophaga clathrata 

 Meig. in Algiers during 1893-1905. Apparently the foregoing 

 writer had only one species of Sarcophaga involved, as was true in 

 the case of the writer during the present studies. 



Second in importance as a controlling factor of D. longipennis 

 was the preying upon the nymphs by the sphecid wasps Priononyx 

 atrata Lep. 



These wasps were always present in large numbers among the 

 hoppers. Being very diligent workers, apparently working from 

 sunrise to sunset during favorable weather conditions, the numbers 

 of the grasshoppers were greatly depleted from their efforts. Dur- 

 ing the observations of the writer, however, only nymphs were noted 

 to be attacked. 



In nearly every instance the single nymph placed in each nest is 

 stung before the excavation is undertaken, but occasionally the bur- 

 row will be completed before this is done. However, the female 

 wasps frequently sting several nymphs during the period of con- 

 structing a single nest, and in one instance, observed by the writer, 

 as many as five were stung by a single female while excavating an 

 individual burrow. In this case it was the last nymph stung which 

 was drawn into the burrow. The nest finished, the Priononyx flew 

 away, leaving the other four victims lying upon the prairie in a 

 comatose condition. The nymphs once stung by Priononyx seldom, 

 if ever, regain consciousness. This habit, naturally, increases the 

 efficiency of this species. 



Usually the hopper is stung in the abdomen, but stinging in the 

 venter of the head regions is common. The wasp, approaching the 

 victim unawares, generally seizes and stings it so quickly that the 

 grasshopper has little opportunity to offer any effective resistance. 

 When a nymph is aware of the presence of a Priononyx it will sud- 

 denly assume the very characteristic protective attitude of defense. 



