28 



Forty-first Report on the State Museum. 



Walsh: in Pract. Ent., i, 1865, pp. 10-12, p. 37-8 (what it is) ; Amer. Ent., 

 ii, 1870, p. 329-30, figs. 3, 4 (referred to Isosoma). 



Walsh-Riley: in Amer. Ent., i, 1869, pp. 119-158 (figures, nat. liist., para- 

 sites, varieties, etc.). 



Bethune: in Ann. Kept. Ent. Soc. Ont., for 1871, pp. 59-61, figs. 58, 59. 



Lintner: in Count. Gent., xxxix, 1871, p. 584 (mode of attack); id., xlix, 

 1884, p. 857 (as Isosoma tritici). 



Packard : in 9th Eept. U. S. G.-G. Surv. Terr., 1877, pp. 693-695. 



Cook : in Rural N. Yorker, xliv. May 9, 1885, p. 314 (as I. nigrum n. sp.) ; in 

 Amer. Nat., xix, 1885, pp. 804-808 (as I. ? nigricm). 



Riley : in Rur. N. Yorlcer, xliv, June 20, 1885, p. 418, fig. 215 (in Ohio) ; in 

 Rept. Commis. Agricul., for 1886, pp. .539-542 ; in Encyc. Brit., Amer. 

 Edit. — Agriculture, page 1:39, fig. 18. 



CoMSTOCK : in Count. Gent., lii, 1887, p. 529 (life-history, remedies, etc.). 



Pieces of wheat straw showing insect attack, were received from 

 Mr. C H. Boyd, of Johnson's Creek, Niagara county, N. Y., on Sep- 

 tember fifth. They had been taken from a mow as a sample of much 

 of the straw in it. The attack was new to those to whom it had been 

 shown, and it was learned that it was quite common throughout 

 Niagara county. 



The straw contained the larvae, apparently; about full-grown of the 



joint-worm liy, Isosoma 

 hordei. The larvae were 

 small, about one-tenth of 

 an inch long, footless, of 

 a yellowish-white color, 

 and embedded in elon- 

 gate cavities in the stalk 

 near one of the lower 

 joints, converting that 

 portion into a hard, 

 woody substance. Their 

 location within could be 

 detected by a smooth, 

 elongated, and more or 



Fig. 10.- 



■The .Joint- worm Fly, Isosoma hoedei, aud 



its galls. 



less swollen portion of the stalk immediately over them, ajipearing as 

 if slightly blistered. 



Sometimes these swellings are larger, more prominent and gall- 

 like, as in the pieces of straw illustrated in Figure 10, at a, in their 

 natural size. The perfect insect that emerges from them through 

 the small round hole shown in some of the galls, is rej^resented in 

 enlargement at h. 



In the portion of the plant infested, and also occasionally, in the 

 deformation, swelling, and bending over of the stalk, the joint-worm 



