96 
1894. Davis, G. C— Bull. No. 116, Mich. Agr. Exper. Sta., pp. 
41-47. 
1896. Webster, F. M.— Bull. No. 68, Ohio Agr. Exper. Sta., pp. 
31-33. 
1899. Webster, F. M.— Bull. No. 112, Ohio Agr. Exper. Sta., pp. 
143-149. 
1905. Webster, F. M.— Circ. No. 67, U. S. Dept. Agr., Bur. Ent., 
pp. 1-5. 
Clover Hay-worm 
Hypsopygia costalis Fab. 
(Pyralis costalis, Asopia costalis) 
The clover hay-worm works in stacked or stored clover, eating 
much of it, and contaminating much more with webs of silk and parti- 
cles of excrement, making the hay unfit for fodder. 
This species, described as long ago as 1775, has been sufficiently 
infrequent in England to be valued by the collector. It inhabits cen- 
tral and southern Europe, northern Asia, northern Africa, and a large 
part of North America. In this country its destructive work has been 
seen in New Hampshire, Massachusetts, Connecticut, New York, 
Maryland, West Virginia, North Carolina, Ohio. Indiana, Illinois, Ken- 
tucky, Tennessee, Alabama, Kansas, Missouri, Iowa, Nebraska, Michi- 
gan, and in Ontario, Canada. 
In Illinois the species is widely distributed, according to the 
records of the State Entomologist, and has done no little damage in 
various parts of the state. 
Injury. — The larvae attack the bottom of a clover stack to a height 
of two feet or more from the ground ; similarly, in the barn, they 
occur near the floor. They interweave the hay with white silken webs, 
intermixed with black pellets of excrement resembling coarse grains of 
gunpowder ; they reduce much of the hay to chaff, and their webs 
give the hay the appearance of being mouldy ; in fact, such hay actu- 
ally becomes mouldy if it has been lying near the ground. This hay is 
refused by horses and cattle and is fit only to be burnt. When the hay 
is removed, swarms of wriggling brown caterpillars are left. 
The pest evidently prefers dry clover hay. In mixed clover and 
timothy, the former is eaten and the latter is left, altho 50 percent of 
such hay may be damaged when the hay is three quarters timothy 
(Webster). One writer, it should be said, has reported serious dam- 
age to pure timothy in Kentucky. Webster reared the larvae on grow- 
ing clover heads, in the insectary, and, furthermore, obtained the moth 
in large numbers (June 3 to July 15) from masses of dead grape 
leaves taken May 5 on the ground in a vineyard. In summer the 
caterpillars are confined to the old unfed hay, and the infestation is 
worst on hay that has lain over, year after year. 
I 
