THE RADISH-FLY : DE5CRIPTI01S" AND HISTORY. 197 



joint being small, the second largo, the third largest and oval, with a 

 two-join tod pubescent bristle on the back, the first of the joints being 

 very minute. The fore-body is oblong, whitish on the sides, with 

 three faint interrupted dusky stripes upon the back. The hind-body 

 is shining gray, rather small and elliptical, tapering to the apex, with 

 a black stripe down the back, the edges of the segments and the region 

 of the scutel being also black. The two wings are large, transparent, 

 iridescent, laid the one upon the other in repose, the longitudinal 

 veins extending to the margin, with two transverse veiniets in the 

 disk. The poisers are pale yellowish. The six legs are black and- 

 bristly, the feet live-jointed, ending in two little claws, and two large 

 pale leathery lobes. 



" The female is of a uniform ash-gray color, excepting the silvery- 

 white face and pale sides of the fore-body. The eyes are widely apart, 

 with a broad black strijie between them, which is shaded into chestnut 

 color in front. The hind-body is larger than in the male and conical 

 toward its apex. The wings have a tinge of yellowish at their bases. 

 The species measures 0.22 in length, and 0.45 in width across the ex- 

 tended wings." 



Natural History. 



The history of this insect does not appear to have been carefully ob- 

 served. Dr. Harris' only statement is that the fly emerges from the 

 ground toward the end of June. Dr. Fitch states that the pupa state 

 lasts for two or three weeks. Professor Cook, of Lansing, Michigan, 

 writes : " The flies are around early- in the spring, for our earliest 

 i-adishes are the ones most liable to suffer from attacks. The eggs are 

 laid on the stem close to the ground. These soon hatch. * * * 

 In June they transform to pupse and to images, and are ready to make 

 a new deposit of eggs. Whether there are more than two broods a 

 year, and whether they attack other plants than radishes, are, so far as 

 I know, still open questions." The observations of Dr. Fitch, in rela- 

 tion to the early appearance of the fly, are somewhat at variance with 

 the above. It was only from his earliest-sown radishes that he ol)- 

 taincd any that were fit for use, but he adds, **for several years past, 

 the first sowing has also been a total failure." It is not imjirobable 

 that with a more thorough establishment of the fly among us, its first 

 appearance in the spring may be earlier than it was wont to be. 



Its Literature. 



Very little, beyond that above referred to and quoted, has been writ- 

 ten of tliis species. We find nothing in tlie Reports of ]\Ir. Glover, du- 

 ring his long connection with the United States Agricultural Depart- 



