39 



the egg, which is of course destroyed. The minute eggs of the 

 parasite are laid inside those of the moth, and hatch there. Dr. 

 Riley mentions three other species of parasites upon tlie web- 

 worm. 



Halesidota carycc, Harr. 



Tiie caterpillars of this moth arc sufficiently abundant to entitle 

 them to a popular name, but I do not know that they have anv. 

 Their general appearance is not very unlike that of the next species, 

 though they are less gaily colored. They are thickly covered with 

 white hairs in tufts, while along the back there are eight black tufts 

 and smaller tufts of longer black hairs at the ends of the botlv. 

 The head and underside of the body are black. These caterpillars 

 feed upon w^alnut, sumach, ash, elm and perhaps other trees. 

 They are sometimes very common and sometimes rare. They are 

 about an inch and a half long when grown. In the last of sum- 

 mer they leave the trees, go to the ground to hide under stones or 

 in crevices. Here they make a hairy cocoon in which they spend 

 the winter. The next June the moths come out. They are rather 

 prettily marked. They are about two inches across the spread 

 wings. The color is light yellow and the front wings are dotted 

 and marked with brown, and there are three irregular rows of 

 almost or quite transparent white spots across them. The hind 

 wings are very delicate and thin, and bear no markings. 



THE TUSSOCK MOTH. 



This insect, Orgyia leucostignia., S. and A., has done much 



Figure 29. 



Latva of Orgyia leucostigma, S. and A. 



damage to the elms in some places. The caterpillar, figure 29, 

 is one of the prettiest we see commonlv. Like the lar\'a of the 



15 



