106 SIXTH ANNUAL REPORT 



and these exceptional cases may be accounted for by supposing the 

 hay to have been stored on the same sites, or in the same situation, 

 for successive years. In confinement, the worms show a tendency to 

 work their way to the bottom of whatever they are confined in, and 

 we may conclude that this tendency is natural. It will account for 

 their being found so generally at the bottom of a stack. Yet, aside 

 from this tendency, it follows that wherever clover is stacked for suc- 

 cessive years on the same foundation, the bottom, coming in contact 

 as it does with the infested leavings of the previous year, will ne- 

 cessarily suffer most. Secondly, as the worms show a preference for 

 the moister and more compact portions of a stack, it will be well to 

 build on a good log or rail foundation. This gives an air passage un- 

 derneath, and is, besides, a commendable practice. Thirdly, I should 

 recommend salting the hay, especially the two or three feet near the 

 bottom ; for while it is a good practice as a preventive of raoldiness, 

 it may also prove an. antidote to the worm nuisance. Mr. Rich. Wray, 

 of English Prairie, Ills., who has suffered much from this insect, and 

 who believes that the infested clover is injurious, and may even prove 

 fatal, to stock, informed me, many years ago, that he had used both 

 lime and salt, with poor results, but that his trials were not thorough. 

 I have little doubt, from some experiments I made, which showed that 

 the worms would not eat well-salted clover, that thorough salting will 

 preserve a stack from their attacks. 



AsoriA cosTALis (Fabr.) — Larva. — Leiigtli 0.70-0.75 inch ; diameter O.OS inch ; 

 general color dull dark-brown with an olivaceous hue. Thoracic joints much wrinkled, 

 the rest each witli two wrinkles, the anterior one usually one-third wider and lighter 

 colored than the other. Each side of dorsum on eacli wrinkh; is a small round pol- 

 ished space, liglitor than the body, with a dark central shiny spot giving rise to a very 

 fine dull-white iiaii-. Along the stigmatal region, on the anterior or lighter wrinkle, is 

 another almost square, light space, somewhat swollen and as wide as the wrinkle, and 

 having two shiny spots, one, smaller below tlie other. At the extreme outer edge the 

 body is generally lighter, with a dark longitudinal, irregular, impressed line, above 

 which anteriorlj% and below it posteriorly, is a small point also giving rise to a hair. 

 Venter lighter than dorsum, with a row of dots and liairs on each side. Legs con- 

 coiorous with venter, the abdominals with a spot and hair exteriorly. 



When young they are nuich lighter than when matui-e, and the head, cervical 

 shield and caudal plate do not become dark till after the last molt. Some specimens, 

 even when mature, are much lighter than others, the two wrinkles often being of the 

 same color, though the insections are always dark. The liglit spaces are not so con- 

 spicuous in the dark specimens. Anterior and posterior usually darlcer than the mid- 

 dle joints. Very lively, wriggling backward as well as forward. 



Cocoon. — 0.50 inch long, oblong-oval, of pure white silk, mixed with excrement and 

 particles of clover. 



Chrysalis. — 0.33-0.36 inch in length. Color hojiej'-yellow, with segments and ineni- 

 Ders clearly defined by the insections being of a deeper color. 



