June, '12] FELT: IDENTITY OF WHEAT MIDGE 287 



the true wheat midge, the Cecidomyia or Contarinia tritici Kirby. 

 There are one or two other species which have been reared under 

 conditions which led the collectors to consider them wheat midges. 

 There is, in addition to the above, Lestodiplosis caliptera Fitch, an 

 undoubtedly predaceous enemj' of the wheat midge and possibly 

 another form with similar habits. The evidence at hand is not suffi- 

 ciently precise to permit a positive opinion as to which species 

 is the destructive wheat midge referred to so frequently in earlier 

 economic literature. It may be any one or all three of the species 

 described in detail below or some other form. The evidence is sum- 

 marized at this time and the species described in the hope that those 

 working upon grain insects will give special attention to this problem 

 whenever an opportunity presents itself for securing valuable data. 

 It is extremely desirable to obtain rearings, preferably numerous 

 adults, from infested fields in widely separated sections of the country. 



Thecodiplosis mosellana Gehin 



Midges tentatively referred to the above species by Prof. J. J. 

 Kieffer of Bitch were reared from wheat chaff containing numerous 

 stout, yellowish orange larvae submitted for identification January 

 12, 1912, by Mr. E. P. Rumsey, Batavia, N. Y. The insects were 

 responsible, according to Mr. Rumsey, for a shrinkage of 25 per cent 

 in the yield of the field. Nearly every head seemed to be affected 

 just before the grain was cut. The larvae were so numerous in the 

 sample sent, a fair representative of several bushels collected under 

 the threshing machine, as to give a distinct yellowish appearance. 

 There appears to have been no record or even suspicion that this 

 European species might have become established in this country. 

 Apparently the same larva was found in wheat heads at Belle Isle, 

 N. Y., June 20, 1899. 



Larva. Length 2.. 5 mm., yellowish orange, stout. Head small, rather long; 

 antennae stout, biartieulate; breastbone bidentate, the teeth diverging, obhquely 

 truncate, the .shaft long, slender and tapering posteriorly. Skin coarsely shagreened. 

 Posterior extremity roundly truncate and with two submedian pairs of rather obtuse 

 tubercles, the outer pair distinctly smaller. 



Male. Length 1.5 mm. Antennae a little longer than the body, thickly haired, 

 reddish brown, yellowish basally; 14 segments, the fifth with stems three and four 

 and one-half times their diameters. Palpi; the first segment short, stout, the second 

 with a length fully thrice its diameter, the third a Httle shorter than the second, the 

 fourth one-half longer than the third. Face yellowish. Mesonotum dull reddish, 

 the submedian lines yellowish, sparsely haired. Scutelliun deep red, postscutellum 

 whiti.'^h transparent. Abdomen with the basal half deep salmon, the distal segments 

 yellov.i^h tran.sparent. Genitalia a variable yellowish and yellowish red. Wings 

 hyaUne. Halteres yellowish transparent, the knob reddish. Coxae and femora 

 basally, j^ellowi-sh, the remainder of the legs a variable light straw; claws long, slender, 



