June, '09] journal of economic entomology 233 



In 1887 Koebele found puparia in Elymu's americanus, Agrostis sp. 

 Bromus ciliatus and Agropyron sp. in California. Flies reared from 

 these were sent to Washington where they were considered the true 

 Hessian fly. The determination of the Elymus material was later 

 disputed by Mr. Theo. Pergande, of the Bureau of Entomology, on 

 some small structural differences between the specimens and some 

 others reared from wheat. 



In 1888 Lindemann reported considerable infestation in timothy 

 and quack in the Russian governments of Tambaw and Woronesh, 

 but he does not say that he reared the adults. 



In 1897 Marchal repeated Forbes' experiments, likewise with nega- 

 tive results, on these grasses: Bromus pratensis, B. mollis, Dactylis 

 glomerata, Festuca pr-afensis, Alopecnrus prateiisis and Hole us lanor- 

 tus. He demonstrated clearly by biological experiments that Mayie- 

 tiola aveme (Marchal) infesting oats in France was specifically dis- 

 tinct from M. destructor (Say). He called attention to eight other 

 species belonging to allied genera that attack native grasses. He thus 

 showed the necessity of verifying the determination of supposed Hes- 

 sian fly puparia in indigenous grasses by the "criterium biologique," 

 and he asserted that evidence of this character was still lacking in 

 all the work done on this insect. 



In 1898 Osbom adopted ^Nlarehal's position as final and pointed out 

 that over the immense wheat-growing sections of the United States 

 no record exists of an infestation in native grasses. 



In 1906 Gossard and Houser found a few eggs laid voluntarily on 

 the following grasses near wheat fields in Ohio : Festuca pratensis, 

 Arrenatherum avenaceum, Poa pratensis, Lolium perenne, Dactylis 

 glomerata, Bromus inermis. Very few eggs were laid on each grass, 

 and none developed except on one plant supposed to be a Lolium, 

 but never satisfactorily determined. Flies were induced to oviposit 

 in vivaria on fox-tail, orchard grass, timothy, redtop, blue grass and 

 wild rye (Elymus canadensis) but none of the larvas developed. 



It will thus be seen that the Hessian fly positively determined from 

 the adults has been secured from quack in California, Kansas and at 

 Forest Hills, Mass. It seems, curiously enough, that Agropyron 

 (Triticum) repens has never been used in breeding experiments, al- 

 though it is closely related to wheat (Triticum vulgare) and is every- 

 where available. 



The writer takes pleasure in acknowledging Professor Wheeler's 

 kind suggestions relating to these observations. 



