THE AMERICAN EXTOMOLOGIST. 



153 



-. . iu;iitiye a character as the hairs on the male ■ 

 antenn* is scarcely worth talking about. "We 

 have ourselves, by immersing a male in hot 

 water, caused the conspicuous whorls of hairs 

 on the antenme to disappear thereafter almost j 

 entirely from view. 



Joixr-'WoRM FtY (Eurytomn trilia. Fitch). On 

 Wheat.— Front shanks dull pale tbIIow; middle and 

 hind shanks blac-k. ' ■ 



R ve-Fl V ( Eur^oma ticalit. Fitch). On Kye.— Front 

 and hind shanks ilull pale rellow: middle shanks black. 



Black-lecgew BiKLE V-fly (Eorytoma AorJei. Har- 

 ri>|. On Barley— Front shanks of the same dusky or i 

 )>laL'kish i-olor with the middle and hind ones. 



YEU.OW-I.EGGED B-iRLEY-FLY {Eurytoma fulr^ipet. 

 Fitch). On Barley —Legs, ineludins all the shanks, 

 liright tawny yello'w. 



In order to test this question, we mounted I 

 and preserved 70 specimens of the Joint-worm 

 dies, bred by us in June from Canada barley- \ 

 galls all received from the same quarter, 23 of \ 

 these specimens being males and 47 females. 

 On carefully examining all these specimens ' 

 time after time tinder the lens, we find that 

 most of them have the pale yellow front shanks 

 stated by Fitch to be peculiar to the Joint-worm i 

 Fly that infests wheat : that not a single speci- 

 men has the distinctly black front shanks stated \ 

 by Fitch to be peculiar to the Black-legged | 

 Barley-fly, although a very few have the front ' 

 shanks slightly clouded outside with black : that 

 two female specimens have the shanks colored in 

 the style which Fitch asserts to be characteristic 

 of the Rye-fly: and that but seven female speci- 

 mens have, with the exception of the front thighs 

 being black, the yellow legs which Fitch assigns 

 as the peculiar character of the Yellow-legged 

 Barley-fly. "We also find numerous intermediate 

 grades between these difterent forms: so that it 

 would be utterly impossible for any rational ento- 

 mologist to separate the 70 specimens into four, . 

 three, or even two parcels, and to consider each 

 parcel as a distinct species, for the simple reiison 

 that it would be impossible for him to draw a 

 distinctive line anywhere. Hence we incline to 

 consider Dr. Fitch's four species of .Toint-worm 

 Fly — as several other species which he has pub- 

 lished are now generally considered — to be 

 mere varieties of one and the same species, and 

 not four distinct species. At all events the 

 coloratioual characters of the shanks, as laid 

 down by Dr. Fitch, do not coincide with the 

 particular i>lauts to which he assigns each 

 coloratioual form. For the majority of our 

 barley-feeding flies correspond exactly in their 

 coloration with his wheat-feeding flies ; and two 

 of them correspond with his rye-feeding flies. 



In further confirmation of the fact, that the 

 Joint-worm Fly which infests barley is the same 

 species as that which infests rye, Dr. Fitch's 



own evidence may be adduced. For he says 

 himself that he captured off the growing rye of 

 a rye-field, at the end of May and beginning of 

 June, three males and several females of what 

 he identified as being the genuine Black-legged 

 Barley-fly. (-V. Y.^Rep. lU. p. 159.) Xow. if 

 these insects did not want to lay their eggs ou 

 the rye. what business did they have there? 



It is true that Dr. Fitch observes that, out of 

 about 1-5 males]and 45 female- bred l>y him from 

 a single lot of Xew York barley-galls, all the 

 specimens without exception had yellow leg-. 

 But we have ourselves remarked, that peculiari- 

 ties of treatment in the breoling of gall-in.sect> 

 sometimes afl'ect their coloration in a most re- 

 markable and hitherto unprecedented manner. 

 For example, from a certain lot of (")ak-galls 

 gathered in the autumn and kept through the 

 winter in a warm room until the following 

 spiing. we bred April Sth-2Sth no less than 47 

 female gall-flies {Ci/nips q. podagr(e.'\Xs\}\i). 

 all of which without exception proved to have 

 perfectl.v black abdomens, ou being carefully 

 examined when recent. The same year, from 

 another lot of the same galls gathereil oft" the 

 same tree about April 1st. aul therefore only 

 retained in the breeding-jar for a few weeks in- 

 stead of six months, and not subjected to an 

 nnuaturally warm temperature through the 

 winter like the first lot. we bred April ISth- 

 24th about 426 females of the same species, fully 

 one-third part of which, when recent, had the 

 abdomen decidedly rufous, pitchy-rufous, or with 

 the base of the segments rufous, the remaining 

 part of them having black abdomens. Think- 

 ing that this rufous color of the abdomen might 

 be due to the immaturity of the specimens, we 

 kept four of those that had rufous abdomens 

 alive in a vial for four days : but at the end of 

 that period their abdomens were still as red .is 

 ever. We may add that the 2:> females fi-om 

 which the above species of gall-fly was origin- 

 ally described by the Senior Editor, and which 

 had_been bred in the same manner as the first 

 lot referred to above, all of them had abdomens 

 of the same uniform black color as the first lot, 

 as is particularly specified in the published de- 

 scription. Thus it results that 70 gall-flies, bred 

 in a particular manner, all of them had black 

 abdomens ; and that about 420 gall-flies, belong- 

 ing to the same species, but bred in a different 

 manner, had, at least one-third part of them, 

 rufous or partly rufous abdomens. Hence we 

 infer that the great difference in the coloration 

 of the legs of Joint-worm Flies, bred respec- 

 tively from similar barley-galls by Harris, by 

 Fitch, and by ourselves, is yery probably due 



