JOINTWORM FLIES. 21 



Nothing was known of its life history until recent years. It has a 

 wide range, being found as far west as Utah, and having been reared 

 from collections of Elymus from Illinois, Indiana, Ohio, and Vir- 

 ginia. It probably occurs wherever Elymus sp. grows normally. 



H. elyrm inhabits the center of the stem of Elymus sp. and has 

 never been reared from any other plant, although repeated attempt's 

 have been made to rear it from wheat, rye, barley, and some of the 

 grasses. There is only one generation a year. Hibernation is in the 

 larval stage, pupation occurs in the spring, and the adults emerge in 

 May. This species is thelyotokous, males never having been observed. 



HARMOLITA ELTMICOLA Phillips and Emery, 



HarmoUta elymicola (10, p. 460) is the commonest species on Ely- 

 mus in the Eastern States and is apparently a strictly eastern species, 

 as it has not been collected west of the Mississippi River with the ex- 

 ception of southeastern Missouri. East of the Mississippi it has been 

 taken in Illinois, Indiana, Michigan, Ohio, and Virginia. 



It forms YQvj prominent galis or enlargements, usually above the 

 second joint from the base of the plant (PI. VI, A) . It has never been 

 reared from any host other than Elymus. Repeated attempts have 

 been made to breed the species on wheat, barley, and various grasses. 

 It has been observed to oviposit in wheat and barley stems, but noth- 

 ing ever developed in these stems. Figure 8 c, shows eggs of this 

 species. 



H. elymicola has only one generation a year. It hibernates as a 

 larva in the old seed stalks, pupates in the spring, and emerges in 

 May. It has proven to be arrhenotokous under control conditions, but 

 both sexes normally occur in nature. 



HARMOLITA ELYMIVORA Phillips and Emery. 



Harmolita elymivora (10, p. 464) is not nearly as abundant as 

 elymicola^ though it apparently has a wider range, having been found 

 as far west as Arkansas. It has also been reared from stems of 

 Elymus sp. collected in Indiana, Michigan, Ohio, and Virginia. 



H. elymivora forms galls in the stems of Elymus sp. just below 

 the head. As a result, the head or fruiting body of the plant never 

 develops (PI. V, C). It is possible that it forms galls of the elymi- 

 cola type also, but the writer has never reared any from such galls. 



The life history is similar to that of elym^icola. Eggs are shown 

 in figure 2, c. 



HARMOLITA RUFIPES Phillips and Emery, 



Harm,olita ruflpes has been described only recently (10, p, 453) , but 

 F. M. Webster is probably the first to have reared it. In Bulletin 42 

 of the Division of Entomology Prof. Webster confused this species 



