Up to the present time cheat has been looked upon onl}' as an 

 undesirable plant growino- among wheat like weeds among- corn, but 

 it now appears to be doubly undesirable on account of its harboring 

 insect enemies of cultivated grains. 



ISOSOMA SECAXiE Fitch. 



This was described by Doctor Fitch in 1861, after he had become fully 

 convinced that these insects were not ])arasitic ]>ut the true depredators 

 among grain." I have not myself encountered it in the study of grain 

 insects, but from the statements of Doctor Fitch it does not seem to differ 

 in habits from Tsosoma liordei and /. tritivl^ and one can not help sus- 

 pecting that a careful study of its life history and development will 

 show that it is one of these species. It was given the connnon name 

 of "rye fly," and adults were reared from straws grown in 1860, 

 emerging about the 1st of June, 1861. The larvae were found to 

 occupy cells in the walls of the rye straw, and not in the base of the 

 sheaths, as was supposed to be the case with I. hordel, though Doctor 

 Fitch describes "the disease which the insect causes in the rye being 

 in every particular like that in barley and wheat. " As we now know, 

 barlej" and wheat are attacked b}" two different species, )jut all three 

 seem to have precisely the same life history, so that whether there be 

 one species or more, the farmer will be able to meet it or them with 

 the same preventive measures. 



DESCRIPTION. 



"Female. — Length, 3.6 mm.; expanse, 6.6 mm. Punctation as with I. hordei; pro- 

 notal spot large, plainly seen from above. Abdomen as long as head and thorax; 

 segments 4 and 5 subeiinal; 6 and 7 together shorter than 5; 2 much longer than 4 

 and 5 together, (^olor black; scape and legs black; front tibiae, knees, and tips of 

 middle and hind til^ia; and all tarsi honey yellow; claw of stigmal club given off near 

 tip of club, somewhat curved; antennte as in /. hordei. 



"Male. — Length, 3 mm. ; expanse, 5 mm. Specimen in poor condition. Expansion 

 of scape more abrupt from tip than with other males described; funicle joints well 

 arched above, scarcely pedicellate, each with 2 indefinite whorls of hair and with no 

 median constriction; each joint twice as long as wide; club plainly divided into two 

 joints, but no trace of pedicel to terminal joint, resembling I. hordei in this respect; 

 petiole a little shorter than hind coxpe and shorter than first abdominal segment." 

 (Howard, Tech. Ser. 2, Div. Ent., U. S. Dept. Agr., p. 19, 1896.) 



In this connection it ma}^ not be out of place to state that I have 

 reared an undetermined species of Isosoma in connection with I. hor- 

 dei from the stems of Elymus canadensis^ growing near Champaign, 

 111., and seeming to affect the grass much in the same manner as 



a Seventh Report Noxious and other Insects of New York, pp. 849-851. 



