JOINTWORM FLIES. 23 



then a member of the Cereal and Forage Insect Investigations 

 force. It forms galls in Elymus sp. It is not known whether it has 

 other hosts. It refused to breed in confinement at Charlottesville, 

 Va. There is one generation a ^^ear and apparently both males 

 and females occur. 



SPECIES WHOSE BIOLOGY IS UNKNOWN. 



The species previously treated in this paper have all been reared 

 repeatedly in cages under artificial conditions with the exception of 

 captiva^ Tufipes^ hesperu^^ elymophtTwra^ and ovata. The writer 

 has never seen living specimens of the remaining six species described 

 by Phillips and Emery (10) — poophUa^ agropyrocola., occidentalism 

 elynhophila^ elymoxena^ and gillettei — or of hromicola Howard and 

 agrostidis Howard, and practically all that is known concerning 

 them is contained in the meager data incidental to collection. Four 

 of these, agrostidis^ hromicola^ elymoxena^ and elytnopMla^ are from 

 California; two, gillettei and poopMla^ are from Colorado; one, 

 agropyrocola., from Utah ; and occidentalis from Xew Mexico. Noth- 

 ing, of course, is known of their life histories. Poophila was reared 

 from Poa lucida, sent in by A. D. Hopldns from Husted, Colo.; 

 agropyrocola and occidentalis were reared from Agropyron sp., the 

 former reared from material sent in by Desla Bennion and the latter 

 from material forwarded by Y. L. Wildermuth; hroniicola was 

 reared from Bromus Hliatus; agrostidis was reared from Agrostis 

 sp. ; elymophila and elymoxena were reared from Elymus sp. The 

 four last species were collected by Albert Koebele. H. gillettei, 

 as the name implies, was reared by C. P. Gillette and was named 

 for him; the host is unknown. Undoubtedly further observations 

 and collections will add many more new species from the Western 

 States, and more particularly from the Pacific Coast States. 



CONTROL MEASURES. 



Farmers, as well as entomologists, have concerned themselves very 

 little about controlling these really serious pests. Fortunately or un- 

 fortunately, depending upon the point of view, the parasites have 

 taken care of the situation to such an extent that only now and then 

 the jointworm {H. tritici) gets out of hand and causes the almost 

 total destruction of a crop in a given locality. Therefore the matter 

 has been viewed very calmly and a toll of from 1 to 5 bushels or 

 more per acre has commonly been tolerated. We have been perfectly 

 content to pay an annual tribute in preference to fighting vigorously 

 to throw off this burden. But for the parasites we should have been 

 obliged to bestir ourselves long ago or else abandon wheat growing 

 in the Eastern States. There is some excuse for this condition of 



