﻿OF THE STATE ENTOMOLOGIST. 177 



[Fig. 37 .] The dorsal figure on the opposite page (Fig. 36) exhib- 



its the general appearance of the mite under a high mag- 

 nifying power, and figure 37 which represents a ventral 

 view of the mite found on our house-flies, and which is 

 doubtless the A. parasiiiown of Latreille, will better 

 show the structure of the head and legs. During some 

 ofthe°HouFe-fly.**^ seasous scarcelv a fly can be caught that is not infested 

 with a number of these blood-red mites, clinging tenaceously around 

 the base of the wings. 



As remarked in my last Report (p. 56) the genus Astoma and 

 probably most other six-legged genera, are only larval or immature 

 forms of some other mites ; and this very Locust mite may be the 

 larva of the Silky mite previously described, for ought we know to 

 the contrary — there is so much to learn yet of the transformations of 

 the Mites. Indeed, Hermann, and some other arachnologists have 

 actually referred Astoma to Tromhidium. In speaking of the Irrita- 

 ting Harvest Mite {Leptus irritans Riley, 6th Rep. p. 122) the so-called 

 Jigger of the Mississippi Valley, and which is, in all probability, an 

 immature form; I have stated my belief that its normal food must, 

 apparently, consist of the juices of plants and that " the love of blood 

 proves ruinous to those individuals who get a chance to indulge it ; for 

 unlike the true chigoe, the female of which deposits eggs in the wound 

 she makes, these harvest mites have no object of the kind, and, when 

 not killed at the hands of those they torment, they soon die — victims 

 to their sanguinary appetite."* The same argument may, I think, be 

 applied to the Locust Mite., 



The Rocky Mountain Locust infested with this mite was sent to 

 me in 1868 by Uriah Bruner, of Omaha, Nebr., and in 1869 by Clark 

 Irvine and C. Twine, of Oregon, T. K. Faulkner, of Whitesville, and 

 Jno. D. Dopf, of Rock Fort, Mo., — the latter gentleman stating that it 

 was fast causing a diminution in the number of its victims. I have also 

 received it from Minnesota and Kansas, and found it on several of our 

 native locusts; while the following passage from an editorial account 

 of the ravages of locusts in Kansas in 1869, which appeared in the 

 Prairie tarmer^ (Aug. 21, 1869,) is a sample of many newspaper 

 accounts, and will show how efficient even a mite may be in killing. 



The course of the locusts was brouorht to a surldeii halt by the operation of some 

 parasite, appearing in the shape of small red mites, which attach themselves to the 

 body, under the wiu'fs, where they suck the carcass to a dry shell ; the dead bodies of 



•Am.\aturalist, Vol. VII, p. 19. 

 E R — 12 



