102 



generations before unknown among these insects in this country, was 

 represented in my rearings from wheat stubble, collected from about 

 New Harmony and Princeton, by tlie spring form mimiUtm. 



Isosoma tritici Ritch was also reared from wheat straw from these 

 localities. Specimens of the latter occurring among the former are quite 

 strongly contrasted, the latter being quite large for these insects and pos- 

 sessing fully deA'eloped wings, whereas the former are much smaller and 

 wingless. Reared also from Elyinvs virf/iniciis, an entirely new food plant 

 for the species. 



Imiioma viactdatiiin Howard was reared in eoiisidcralile numbers from 

 the stems of cheat, Bromvs sccdliniis. The species was described from 

 individuals collected by me about Lafayette during .June, 1885, and May, 

 1886, but the food plant has up to tliis time remained unknown. 



Isosoma albomaciilutiis Ashmead, originally described from West Vir- 

 ginia, was reared from Broiuus secalhiiis in great numbers, also to a lesser 

 extent from the stems of EJjjmvs rlvoinicus. 



Isosoma ehjmi French was reared in profusion from Elymus. This 

 species, at one time supposed to be a wheat insect, confines itself strictly 

 to the grasses. I have never I'cared it from Avlieat straws and have never 

 reared Isosoma finivdc from anj'tliing else except wheat. 



Isosoma (fiavipes) liordci Harris was reared from stems of Ehjmiis can- 

 adviisis and in such nuiriliers as to give economic importance to the fact. 

 The rearing of the .Joint Worm species, /. hordei, and one of the wheat 

 straw worm species, I. frit id, from Elymus, both of which are wheat in- 

 sects, shows very plainly that tlioiiuli tlie farmer may overcome these in 

 his cultivated fields, unless he is careful to destroy these grasses growing 

 along roadsides and in uncultivated fields, a continual reinfestation will 

 be going on, and he must fight his foes in the grasses as well as in his 

 cultivated grains. Besides these, there is a species of Isosoma, of which 

 I have only been al;)le to rear the male, but the larva? of which infest the 

 stems of Tric'Kspis scslooidcs, and I have reared these from stems col- 

 lected near Orleans, Indiana. There is prol)al)ly still another species of 

 Isosoma, at present not distinguishalile from /. hirtifroiis Howard. This 

 last had until now been known only from rye straw in California. I did 

 not rear this from Indiana, lint in Illinois the common cheat, Bromns 

 secalinvs, appears to be its sole food plant. The larvie are found in the 

 stenis, and as the stems of cheat in Indiana contain an abundance of 



