Alfalfa in Kansas. 399 



Methods of Control. 



Inasmuch as the larvae of the chalcis-fly are able to pass completely 

 through the first generation in the earliest-maturing pods, and since 

 the early pods have an especially large percentage of the seeds infested, 

 every effort should be made to cut the alfalfa and get it in the barns or 

 stacks before the larvae mature. The early-maturing pods developing on 

 plants in waste places, along ditch banks and fence lines, are a source 

 of danger and should be cut or destroyed. If these methods of control 

 are practiced it will greatly lessen the numbers of the second generation 

 and thus protect the main seed crop. 



The screenings which are left after the alfalfa is threshed often con- 

 tain large numbers of infested seeds, and unless the screenings are burned 

 or piled up so as to decay, the adult chalcis-flies will emerge from them 

 the following spring. 



THE CLOVER-HAY WORM. 



(Hypsopygia aostalis Fab.) 

 Dirty-white to brownish worms, with head more or less reddish, when 



fully grown measuring about three-fourths of an inch in length, 



matting and injuring alfalfa hay in stack and mow, giving the hay a 



moldy appearance. 



The clover-hay worm has become quite abundant over Kansas wherever 

 alfalfa and clover are grown. This worm attacks alfalfa, clover and 

 timothy hay, both in the mow and the stack, cutting the leaves into chaffy 

 pieces and webbing the mass together by an abundance of silken threads, 

 which it is the habit of the worm to spin at all times. Hay so infested 

 looks moldy and matted, and the abundance of silken threads mingled 

 with the excrement of the worms renders the hay distasteful and even 

 unfit for stock. 



History and Distribution. 



It is generally supposed that this insect is a native of Europe and early 

 became introduced into this country. It now occurs over Europe, southern 

 Canada, and the greater part of the United States. With the extensive 

 growing of alfalfa it has become a serious pest throughout the alfalfa- 

 and clover-growing states. 



Habits and Life History. 



The worms are usually noticed toward the bottom of the stack. How- 

 ever, in hay kept over the second year, they may be all through the stack. 

 The "worms" when young are of a dirty-white color, but as they grow 

 older they become brown, with the head more or less reddish, and when 

 mature measure about three-fourths of an inch in length. The larvae are 

 very active and wriggle forward or backward with equal ease. They spin 

 silken webs in the hay, and frequently suspend themselves by a thread 

 when moving about. The worms work in the hay all through the fall, 

 winter and the early part of spring. The pupal stage is passed in a thin 

 silken cocoon, spun in some protected nook or near where the larval life is 

 passed. The adult moth, which appears from the middle of May on 

 through June and early July, is a little insect with wings spreading 



