JOINTWORM FLIES. 13 
LIFE HISTORY. 
This is one of the easiest species to handle in breeding cages. In 
fact, it breeds more freely than any other species, tritic'i not excepted. 
There is only one generation a year, the larvae remaining in the 
old barley stubble until the following spring, when they pupate and 
then emerge as adults during May, at least in the vicinity of Char- 
lottesville, Va. Plate IV, D, E, and F, shows three positions of a 
female during oviposition. Figure 2, d, e, shows the egg before and 
after oviposition. 
H. hordei is normally thelyotokous. In a period of 4 years' breed- 
ing, during which several thousand specimens have been reared, not 
more than three or four males have appeared. 
Under actual test one female hordei deposited 71 eggs in 3 days 
and then died. Upon dissection 3 eggs were found in her abdomen. 
From this it would seem that under favorable conditions for egg lay- 
ing the lives of adult females of the species are very short. If the 
weather is stormy and cool, however, they will live two or three times 
as long. 
THE RYE JOINTWORM. 1 
The rye jointworm was described in 1861 (4) , so it will be seen that 
it is one of our earliest known species. For years, however, it was 
considered an invalid species and was thought to be hordei masking 
under a new name. There appears to be no record of the rye joint- 
worm ever doing as serious injury as tritici, hordei, or grandis. 
Harrrwlita secalis, like hordei, is almost extinct to-day and ap- 
parently for the same reasons. In fact, it never has had the oppor- 
tunity to become a serious pest on account of the fact that rye prob- 
ably has never been grown as generally in adjacent fields and through 
consecutive years as have barley and wheat. The rye jointworm has 
had to depend largely upon volunteer rye and to make long journeys 
to the nearest rye fields in order to maintain itself. 
The rye jointworm, in common with several other members of 
the genus, is thelyotokous, males very rarely occurring and appar- 
ently being unnecessary to the vital economy of the species. But for 
the fact that practically every specimen that emerges is a female 
and capable of perpetuating its kind, secalis would undoubtedly have 
become extinct long ago. 
Fitch described secalis from Pennsylvania in 1861. F. M. Web- 
ster collected the species in Ohio in 1904 and C. N. Ainslie collected 
it in Michigan in 1906. The writer has collected it in Ohio, Indiana, 
and Pennsylvania. 
1 HarmoUta seoaM.s Fitch. 
