JOTNTWORM FLIES. 13 



l.ll'K HISTORY. 



This is one of the easiest species to handle in breeding cages. In 

 fact, it breeds more freely than any other species, triticl not excepted. 



There is only one generation a year, the larvic 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 &gg before and 

 after oviposition. 



H. hordel 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 hordel 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 Qgg 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 knoAvn species. For years, however, it was 

 considered an invalid species and was thought to be Jiordei 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. 



Harmolita 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 journey fe 

 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 Harmolita secalis Fitch. 



