304 WHEAT THRIPS — IN WISCONSIN. 



thickened towards their tips, the hind pair heing very long, and the legs are pale 

 yellowish, with the thighs and the thickened ends of the shanks hlack. The abdo- 

 men is elliptic. The antennse in the males are thread-like and nearly as long as 

 the body, composed of fourteen joints, which are very distinct, equal, oval, a third 

 longer than broad, the apical one being a little longer and egg-shaped, and the ba- 

 sal one club-shaped and thrice as long but scarcely thicker than the following ones. 

 In the female they are shorter and composed of twelve joints which are compacted 

 together, the three last enlarged and forming a kind of knob or club, the last joint 

 nearly as long as the two which precede it, its end bluntly rounded. 



Upon the heads and stalks in June and July, exhausting the juices of the 

 kernels and rendering them dwarfish and shrivelled; exceedingly minute, 

 active, long and narrow, six-legged insects, of a bright yellow or of a shin- 

 ing black color. 



The Wheat Thrips. Thrips Tritici, new species. 



The Three-banded Thrips, Coleothrips trifasciata, new species. 



My attention lias been called to these insects by a letter from 

 David Williams, dated Geneva, Wisconsin, July 9th, 1855, which 

 says : " Enclosed I send you specimens of a minute little insect 

 that is causing some alarm in this vicinity. They are found in 

 all blossoms in great numbers. They first made their appear- 

 ance about the middle of June, or at least they were then first 

 noticed, so far as I have heard. For about two weeks they were 

 found in the blossoms of wheat and of clover, causing numbers 

 of the blossoms to wither, and in some cases the kernel was also 

 attacked. About a fortnight ago we had a very heavy fall of 

 rain, which appeared to destroy them; but within a few days I 

 have noticed their reappearance in countless numbers. They 

 are very nimble, requiring good eyes and ready fingers to secure 

 them, and I was obliged mainly to my wife for the capture of 

 those which I send you." 



The insects alluded to in the above extract are so minute, that 

 had only two or three specimens been sent me, I should have 

 been unable to give any definite account of their species. . An 

 acknowledgment is due Mrs. Williams for the number of these 

 insects which she enclosed in the quill — a task which the bung- 

 ling fingers of a man could scarcely have accomplished. Among 

 them I find specimens in all the stages of their growth, and am 

 hence able to present a tolerably complete history and description 

 of the species; although it is only from living specimens that such 



