tat 
SOME STUDIES OF THE CLOVER HAY-WORM, ASOPIA COSTALIS. 
By F. M. WEBSTER, Special Agent. 
Although much has been written of this insect, yet, so far as the 
writer has been able to gather from the literature to which we have had 
access, little if anything has been learned of its habits since it was 
studied by Dr. Riley, as portrayed in his Sixth Report on Insects of 
Missouri, p. 102. 
Late in April of the present year we received a number of these 
larvee from Prof. W. t. Chamberlain, of Hudson, Summit County, Ohio, 
with the statement that they were destroying hay in that neighborhood. 
In accordance with instructions from Professor Riley we visited the 
farm of Mr. Chamberlain on April 27, in order to investigate the matter 
and see if some means could be devised whereby the pest could be de- 
stroyed. 
On arriving at our destination we found that a stack of about 20 tons, 
standing in the open field, had been damaged fully 50 per cent, although 
the hay was fully three-quarters timothy. About 5 tons of this hay was 
handled over and re-stacked beside the old site, in the mean time being 
thoroughly dusted with a mixture of 10 pounds of powdered pyrethrum 
thoroughly mixed in 50 pounds of flour. This was done with the un- 
derstanding that the whole stack was to be removed in a short time, 
when the results of the application could be ascertained. A small 
quantity of hay thus treated and piled up to one side was examined 
next day, and a majority of the larve were found to have been de- 
stroyed. The stack, however, contrary to our expectations, was allowed 
to stand for nearly six months, when of course all hope of learning any- 
thing of the effect of the experiment had long before vanished. The 
result, though admitted a failure in this case, demonstrated the practi- 
cability of the measure, and the smaller experiment gave evidence of 
its efficiency. Other farmers in the vicinity reported serious losses 
through the same insect, and in some cases the hay had been so badly 
injured that it had been burned on the ground, and this, too, as early 
as late September or early in October of the previous year. 
A great number of larve were taken from Mr. Chamberlain’s hay, and 
placed in breeding cages. These continued to feed on the dry hay for 
a considerable time, pup being first observed on May 25. Growing 
clover plants were now transplanted to the breeding cage. Moths is- 
sued from cocoons on June 12, and also on later dates. . To all appear- 
ances the eggs were placed in the heads of the clover, which, with the 
rest of the plant, was kept alive and growing. On July 1, young larve, 
some very small, others half-grown, were found in the heads now turn- 
ing brown but not dead, and the leaves being green. August 6, pup 
and larve, both partly and quite full-grown, were taken from the cage, 
and two days later adults also began to emerge. These adults were 
