132 DRAGON FLIES VS. MOSQUITOES. 



My friend Lieut. H. O. S. Heistand, Eleventh Regi- 

 ment of Infantry, U. S. Army, told me he had seen 

 mosquitoes quite as thick at Camp Poplar River, Mon- 

 tana, a few years before, and had seen them disappear as 

 if by magic. He said there suddenly appeared a species 

 of "devil's darning needle" or dragon fly, of rather a large 

 size. These insects flew in lines slowly. At first he did 

 not think they had anything to do with the mosquitoes' 

 disappearance, but the change was so sudden, and without 

 sufficient change in the temperature to account for it, that 

 he was forced to the conclusion that this insect was at the 

 bottom of it. This, he said, was corroborated by some 

 "squaw men" and Indian traders who had been at Camp 

 Poplar River for several years. They said these flies did 

 not appear every " mosquito year," but when they did they 

 came in droves and cleared the place out. They called 

 them " mosquito hawks." 



While sitting on the target range one day in July, 

 toward the end of the third week, I think, with the mos- 

 quitoes as thick as ever, we were talking about the mos- 

 quito hawk, and wishing he'd hurry up. Just then Lieu- 

 tenant Heistand shouted, " There's one now ! " For some 

 time before this I had given up slapping myself, as I 

 had not been so much troubled. On looking around I 

 saw a number, about a dozen, of the largest dragon flies 

 I ever saw. If I remember correctly, they had four 

 wings, six legs, were about two inches long, and of a 

 dark brown color. I picked up a dead one some time 

 later, and was about examining it when I was called 

 away. I lost the specimen, and so cannot be certain of 

 my description. The wings had a fine network of blood- 

 vessels (?) and had the faintest kind of an emerald green 



