io6 FARM FRIENDS AND FARM FOES 



for another brood of Web-worms. There is thus but a single 

 generation in a season. 



One of the most destructive moths that has ever ap- 

 peared in America is the famous Brown-tail Moth, which 

 has already done an enormous injury in New England, 

 and which threatens to become widely distributed over the 

 country. This pest seems to have been accidentally intro- 

 duced with a shipment of nursery stock from Europe. It 

 is especially troublesome not only because the caterpillars 

 feed upon practically all kinds of deciduous trees, but also 

 because their bodies are covered with poisonous hairs that 

 cause great suffering when they get upon the human skin. 



The Brown-tail Moth passes the winter in characteristic 

 nests composed of compact masses of leaves fastened to- 

 gether by silken webs. Inside each of these nests, there 

 are commonly several hundred tiny caterpillars. When 

 spring comes, these little caterpillars leave the nests when 

 they wish to feed, crawling along the twigs until they 

 reach foliage. At first they return to the nests at night 

 and when not feeding, but as they grow larger, they are 

 likely to desert them altogether. They continue to feed 

 and grow until about the middle of June. Each caterpillar 

 then spins around itself a silken cocoon, which is attached 

 to some convenient shelter, commonly the leaves of the 

 food tree. Inside these cocoons, the caterpillars change to 

 chrysalids, and three or four weeks later again change to 

 the peculiar whitish moths, with a tuft of brown hairs at 

 the end of the body of the females. This tuft gives the 

 insect its common name. 



These moths appear in June, and lay eggs in clusters of 

 two or three hundred each on the leaves, generally near 

 the ends of the branches. During the latter part of the 

 summer these eggs hatch into small caterpillars, which 



