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. elymi 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 ELYMICOLA Phillips and Emery. 
Harmolita 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 very prominent galls 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 <?, 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 Elyrrms 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 elymicola. Eggs are shown 
in figure 2, c. 
HARMOLITA RUFIPES Phillips and Emery. 
Harmolita rufipes 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 
