32 



to understand. All of these malformations as well as others may 

 be found in the stems of Elymus canadensis in abundance, from 

 which swarms of the adults will emerge in late May and early June. 

 Owing to the woody nature of these abnormal growths, straw attacked 

 by this species is more likel}^ to be broken up into small bits, and 

 these go in with the grain at thrashing, therel)y increasing the dan- 

 ger of transportation from one localit}^ to another, but to offset that, 

 as it were, there is likel}' to be a greater proportion of the insects 

 left in the stubble than with the other species, as the affected straws 

 are usually more stunted in growth and shorter. At present there is 

 no other insect attacking wheat, rye, or barley that causes similar 

 growths in the straw except Isosoma tritlcl Fitch, in wheat, and the 

 farmer can hardly mistake the work of these two pests for those of 

 any other in his fields. 



DESCRIPTION. 



^'Female. — Length, 3.6 mm. ; expanse, 6 mm. Pronotum and mesonotum minutely 

 but strongly rugulose, smoother than /. tritici; metanotum more coarsely rugulose, 

 the larger elevations taking a longitudinal direction, no central furrow or carina; 

 pronotal spot very small, not visible from above. Abdomen as long as head and 

 thorax together; joints 4, 6, and 7 subequal in length, the fifth a little longer; joint 

 3 a little longer than 4, 2 hardly longer than 3 and 4 united; funicle joints 2 to 5 sub- 

 moniliform, but still a little longer than broad. All legs (except coxfe) and antennae 

 honey-yellow, flagellum and femora a little darker; claw of stigmal club straight, 

 given off well before tip of club; pilosity sparse. 



"Male. — The only males which I have seen are the two from the Harris collection. 

 These are both in very bad condition; neither had an abdomen and one has no 

 antenna;. With the other, but three funicle joints remain on the left antenna (the 

 others being broken off) and four on the right, but the latter are still inclosed in the 

 pupal sheath. The three funicle joints remaining on the left antenna are not pedi- 

 cellate, very slightly arched above, and furnished with close, moderately short hair 

 not arranged in whorls; joint 1 longest, 2 and 3 successively decreasing. Joint 4 is 

 still shorter, judging from the sheathed right antenna." (Howard, Tech. Ser. 2, 

 Div. Ent., IT. 8. Dept. Agr., pp. 18, 19.) 



The foregoing description was drawn up from specimens in the 

 Fitch collection, labeled, in Fitch's handwriting, ''^ Eurytoma fulvipes 

 Fh. ;■" other specimens from the Harris collection, reared from barley, 

 June 15, 1830; other specimens from '■'"Canada West," and still others 

 reared b}^ myself froiu stems of Elymus canadensis growing near 

 Champaign, 111. This is the Ichneumon Iwrdel described by Harris 

 in the New England Farmer, the Eurytoma fidvipes described by 

 Fitch in his seventh report, and the Isosoma Tiordei mentioned bj^ 

 Walsh in the American Entomologist (Vol. II, p. 330). 



The larva, except from its larger size and habit of living within a 

 cell, is not distinguishable from that of the other species of grain- 

 infesting Isosoma. It is little larger than that of I. grande^ found in 

 May and early June, and it has the universal 3'ellowish-white color. 

 The same uiay be said of the pupa. 



