220 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



reduce much of the hay to chaff, and their webs give the hay the 

 appearance of being mouldy; in fact, such hay actually 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 work of the caterpillars is usually noticed in late winter and 

 spring. 



Life History. The moths appear from the middle of June 

 until early July in the Northern States and most of the first 

 generation have disappeared by the end of July. The moths 

 have a wing expanse just under an inch, with silky wings, tinged 

 with purplish above, margined with orange and fringed with 

 golden yellow. On each side of the fore-wings are two large, 

 golden spots which divide the anterior margin into thirds and 

 continue backward as narrow lilac lines (Fig. 157). The hind- 

 wings are marked by two transverse, wavy, straw-colored lines. 



As soon as some clover-hay is found the female deposits her 

 eggs and the caterpillars feed upon it. When full grown they 

 are about three-quarters inch long, of a dull-brown color. The 

 segments are divided by a transverse groove, and each bears 

 several shining areas, with a fine white hair in each. White 

 silken cocoons, one-half inch long, covered with bits of hay 

 and excrement, are made by the larvae in the hay or in cracks 

 and crevices of the barn, in which they transform to pupae, which 

 are of a honey-yellow color, with the parts clearly defined by the 

 darker color of the sutures. The moths of the second brood 

 emerge from the middle of August until September 1st, but may 

 be found flying until late October. Caterpillars of all sizes may 

 be found in barns throughout the winter and pupate in the spring. 



Control. Usually no serious injury is done except where 

 clover-hay is kept over the second year or longer. When it is 

 fed out each spring, before the next crop is harvested, there is 

 no food for the young caterpillars, and they perish before the 

 new crop comes in. Consequently mows should be cleaned 

 out each spring. New clover-hay should never be placed on 

 top of old hay, and stacks should be placed at some little distance 



