152 



THE AMEEICAN ENTOMOLOGIST. 



Hy which came forth thus was the true Joint- 

 worm Fl)'.* As already shown, the flies that 

 emerged from tliese Canada galls in the suc- 

 ceeding summer, came out from June 9 th to 

 June 16th and suhsequeutly. 



Parasites of the Joint-worm. 



On cutting open a great number of tlie cells 

 of the dry barley-galls, obtained from Canada 

 in September, we found in one of them a small 

 stout parasitic larva, of a pale glaucous color, 

 attached externally, in the manner common 

 with the larvje of many Chalcis flies, to the 

 half-dead and blackened and partially shrunken 

 carcass of one of the true gall-making Joint- 

 worms . In another cell we found a much larger 

 parasitic larva, evidently belonging to the same 

 species, which had apparently devoured entirely 

 the body of its victim. And from the body of 

 stiU another Joint-worm, wounded by accident 

 in opening the cell, but which was neither 

 shrunken nor discolored, there emerged under 

 our very eyes a third para^tic larva, of medium 

 size, and apparently belonging to the same spe- 

 cies as the two just now referred to. Thus it 

 would seem that in the earlier stages of its ex- 

 istence tills parasite is an external feeder, but 

 subsequently penetrates inside the body of its 

 victim after the more iisiial fashion in such 

 cases. In the summer of the succeeding year, 

 we bred 31 specimens of what is evidently the 

 perfect fly of this same parasitic larva, from the 

 same lot of barley-galls in which we found the 

 above three parasitic larvas, and from which we 

 reared such hosts of the true Joint-worm Fly. 

 Out of this lot of galls, 17 male parasites came 

 out from June 11th to 22nd, and 14 female para- 

 sites from June lith to 28th, thus showing that 

 in this species also the males appear several 

 days on the average before the females. Below 

 we give figures of both sexes of this insect, 

 which is an entirely new and undescribed spe- 

 cies, and which we have called " The Chalcis-' 

 [Pig. 114.] 



Colors— Blue-black; abdomen coppery. 



eating Chalcis-fLj" (Semiotellus chalcidipha- 

 gus). It is a true Chalcis-tLj like the Joint- 

 * Quoted by Fitch, N. Y. Rep. Ht. p. U9, 



worm Fly, but belongs to an entirely different 

 group of that extensive and much neglected 

 family. The female (Fig. 114, a,) is distin- 

 guishable at the first glance from the male (Fig_ 

 114, 6,) by the front wings having a large dark 

 smoky cloud on their middle. Those that de- 

 sire a fuller description of this species in its 

 difierent stages, are referred to an article upon 

 certain groups of Chalcis flies, from the pen of 

 the Senior Editor, which will probably appear 

 before long in the Transactions of the American 

 Entomological Society. 



Two other Chalcis flies, quite distinct from 

 the above, were found by Dr. Harris and Dr. 

 Fitch to be parasitic upon the Joint- worms that 

 infest wheat in Virginia. But aB we have no 

 personal knowledge of these insects, and the 

 descriptions given of them are very brief and 

 imperfect, we shall say nothing further on this 

 subject. 



Are there different Species of Joint-vvopni ? 

 It will have been long ago noticed by the 

 entomological reader that, in all that we have 

 said above respecting the Joint-worm and its 

 habits, we have assumed the race tliat infests 

 barley to belong to the same species as that 

 which infests wheat, and both of them to the 

 same species as that which infests rye. Such 

 was also the opinion of Dr. Harris, who had 

 bred very numerous specimens of the perfect 

 Fly, both from Massacluisetts barley-galls and 

 from Virginia wheat-galls. " The only apparent 

 difference," he observes, " between them con- 

 sists in the"color of the front shanks; these, in 

 the wheat-insects, being pale yellow, and faintly 

 tinged with black only on the outer edges in a 

 few individuals;" whereas the same author 

 describes the barley-insects as having their front 

 shanks "blackish."* Dr. Fitch, however, has 

 manufactured four species out of the Joint-worm 

 Fly, two of them infesting barley, one wheat 

 and one rye, to each of which he has given dis- 

 tinctive names. These four so-called species he 

 acknowledges to differ only in the coloration of 

 their shanks, and — so far as regards the fourth ' 

 species — in the antennse of the males being less 

 profusely surrounded by whorls of hairs than in 

 the other three species. The colorational differ- 

 ences specified by Dr. Fitch may be concisely 

 expressed in the following tabular form, copying 

 as near as maybe Dr. Fitch's own language. f 

 The number of males examined by this author 

 was so limited — iu some of his so-called species 

 but one or two — that the assumed difference in 



* See Harris, Injurious Insects, pp. 554and5.i6. 

 t See his JV. T. Reports IIF. , p. 154. 



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