THE WHITE-SPOTTED TUSSOCK MOTH. 



263 



towns, parks, gardens, and orchards than in forests. As this insect has 

 recently been studied by Professor Riley and his assistants, I repro- 

 duce their results: 



The eggs. — Daring the month of Juue, and more especially late in fall and through- 

 out the winter, glistening white objects may be seen on the trunks and the larger 

 branches of trees, or in the corners of the fences near by, or on bunches of dead leaves 

 hanging on the tree (see Fig. 102 a). Upon examination these masses will be found 

 to be glued on to a cocoon of dirty gray color, and to consist of numerous perfectly 

 round, cream-white eggs, which are partly covered by a glistening white froth or 



-<e 



Fig. 102. — Orgyia leucostigma : a, female ou cocoon; 6, larva; c, female pupa; d, male pupa; e, male. 



Riley del. 



spittle-like matter. In one of these egg-masses which we received from Kansas we 

 have counted as many as 786 eggs, while from another mass we obtained upward 

 of 400 young caterpillars. 



The young caterpillars scatter all over the tree soon after hatching. When dis- 

 turbed they make free use of a fine silken thread, which they spin, and by which 

 they let themselves down. The fall-grown larvae are often seen to change quarters 

 and travel from one branch to another or from one tree to another. Their rather 

 quiet way of moving contrasts strongly with the nervous movements of the Fail 

 Web-worm. 



In the latitude of St. Louis, Mo., and Washington, the eggs begin to hatch about 

 the middle of May, and the newly-born caterpillar, not quite 3 millimeters in length, 

 is of dull whitish-gray color, with the under side paler, the upper side being covered 

 with rather long hairs and tufts of a dark-brown color. In two days from hatching 

 small orange spots begin to appear along the back, and on the seventh day the first 



'EiG. Wi. — Orgyia leucostigma: female caterpillar. Riley deJ. 



molt takes place, to be followed at intervals of six days each by the second and third 

 molts. The changes that take place during this time in the appearance of the cater- 

 pillar are remarkable, and after the third molt it is a beautiful object and of striking 

 appearance (Fig. 103). 



Larva. — The head and two little elevated spots situated on joints 9 and 10 are 

 bright vermilion red; the back is velvety black with two bright yellow subdorsal 

 lines, and another yellow line each side along the lower sides. The whole body is 

 thinly clothed with long pale-yellow hairs, originating from small wart-like eleva- 

 tions. Four cream-colored or white dense brushes of hair are in a row on the middle 



