588 DIPTEEA. 



letter by Mr. Christopher Gullet, written in 1771, and 

 published in the " Philosophical Transactions " for 1772. 

 "What the farmers call the yellows in wheat, and which 

 they consider as a kind of mildew, is, in fact, occasioned 

 by a small yellow fly, with blue wings, about the size of 

 a gnat. This blows in the ear of the corn, and produces 

 a worm, almost invisible to the naked eye ; but, being seen 

 through a pocket microscope, it appears a large yellow mag- 

 got, of the color and gloss of amber, and is so prolific that 

 I distinctly counted forty-one living yellow maggots in the 

 husk of one single grain of wheat, a number sufficient to 

 eat up and destroy the corn in a whole ear. One of those 

 yellow flies laid at least eight or ten eggs, of an oblong 

 shape, on my thumb, only while carrying by the wing 

 across three or four ridges." 



In 1795, the history of this insect was investigated by 

 Mr. Marsham,* and since that time Mr. Kirby,f Mr. Gorrie, 

 and Mr. ShirreffJ have also turned their attention to it. 

 The investigations- of these gentlemen have become very 

 interesting to us, on account of the recent appearance in 

 our own country, and the extensive ravages, of an insect 

 apparently identical with the European wheat-fly. The 

 following account of the latter will serve to show how far 

 the European and American wheat-flies agree in their essen- 

 tial characters and in their habits. § 



The European wheat-fly somewhat resembles a mosquito 

 in form, but is very small, being only about one tenth of an 

 inch long. Its body is orange-colored. Its two wings are 

 transparent, and changeable in color ; they are narrow at 

 the base, rounded at the tip, and are fringed with little hairs 

 on the edges. Its long antennae, or horns, consist, in the 

 female, of twelve little bead-like joints, each encircled with 



* Transactions of the Linnsean Society, Vol. III. p. 142, and Vol. IV. p. 224. 

 t Ibid., Vol. IV. p. 230, and Vol. V. p. 96. 



J Loudon's Magazine of Natural History, Vol. II. pp. 323 and 448. 

 § See also my article on wheat insects in the New England Farmer, for March 

 31, 1841, Vol. XIX. p. 306. 



