172 MOSQUITOES OF NORTH AMERICA 



Recently Mr. W. L. McAtee, of the U. S. Biological Survey, while in Arkansas, 

 found the curious " thread bug," which is often common about farm houses, 

 capturing mosquitoes and has furnished us the following note : 



" There were 3 or 4 Emesa longipes on each window screen of the house in 

 which I stayed at Big Lake, Ark. Mosquitoes would accumulate on these screens 

 each evening and be eaten the next day by the Emesa. I picked up some 

 Anopheles quadrimaculaius that had been sucked dry by the bugs." 



Undoubtedly many other predaceous insects capture adult mosquitoes and 

 Eysell mentions bugs (Hemiptera-heteroptera), locusts (Orthoptera), scorpion 

 flies (Panorpidge), wasps and robber flies (Asilidse), but we have seen no exact 

 observations on these forms in relation to mosquitoes. 



MITES. 



Certain acarids are frequently noticed attached to the bodies of adult mos- 

 quitoes. One of us (Howard) has quoted a letter from Mr. E. P. Salmon, of 

 Beloit, Wisconsin, in which it was stated that one of these mites attacks the mos- 

 quitoes of Madeline Island a few weeks after their appearance in June, and that 

 from the time the little red creature appears under the mosquito's wings the 

 latter begins to lose its strength. " After a few weeks, along toward the end of 

 July, the mosquito ceases to be very troublesome and seems to be fighting with 

 his parasite for his life." The writer stated that the parasite is probably one of 

 the red mites found upon flies and particularly upon the common house fly. 

 Mosquitoes being aquatic insects, it was suggested that the mite observed by Mr. 

 Salmon might be one of the little water mites of the family Hydrachnidse, but 

 that the mosquito issues from its pupa so rapidly that this was hardly likely 

 to be the case. It was suggested that it might be one of the Trombidiidse, the 

 young of which may crawl upon the mosquito when it is at rest upon the plants 

 (Howard's Mosquitoes, pp. 165-166). 



Since that time a number of these mites have been sent in and others have 

 been examined by other observers. All have been found to be hydrachnids and 

 so far as known to us there is no exact record of the finding of a trombidiid on 

 a mosquito. Specimens of these mites taken from a mosquito at Kanawha Sta- 

 tion, W. Va., by Dr. A. D. Hopkins, have been determined by Mr. Nathan Banks 

 as larvse of the hydrachnid genus Eylais. Larvae of an Eylais have also been 

 determined by Mr. Banks upon mosquitoes from the Philippine Islands, sent in 

 by Dr. Clara S. Ludlow. Other larval hydrachnids found upon mosquitoes have 

 been sent to us from the Great Slave Lake by Ernest Thompson Seton. We 

 have ourselves frequently found them and it may be stated, in a general way, 

 that their presence on mosquitoes is a common occurrence. Dye, previously 

 cited, gives accounts of a number of instances in which larval hydrachnids have 

 been found upon adult mosquitoes in different parts of the world. These larvse, 

 according to Blanchard, nourish themselves at the expense of the host, and in 

 certain cases undoubtedly bring about its rapid death. Interesting observations 

 upon one of these larval hydrachnids have been made by Sergent, in Algeria. 

 There he found that Anopheles maculipennis carried these hydrachnids in the 



