THE FALL WEB-WORM. 



245 



growth and wander about seeking places for transformation from the end of August 

 to the end of September. 



The following general remarks upon the different stages refer to Washington and 

 localities where the same conditions hold: 



The eggs (Fig. 85, 6).— The female moth de- 

 posits her eggs in a cluster on a leaf, some- 

 times upon the upper and sometimes on the 

 lower side, usually near the end of a branch. ,,^^^ 

 Each cluster consists of a great many eggs, y^ 

 which are deposited close together and in reg- '^ 



ular rows, if the surface of the leaf permits it. 

 In three instances those deposited by a single 

 female were counted. The result was 394, 

 427, and 502, or on an average 441 eggs. But 

 in addition to such large clusters, each female 

 will deposit eggs in smaller and less regular 

 patches, so that at least 500 eggs may be considered as the real number produced 

 by a single individual. The egg, measuring 0.4™", is of a bright golden- yellow 

 color, quite globular, and ornamented by numerous regular pits, which give it under 

 a magnifying lens the appearance of a beautiful golden thimble. As the eggs ap- 

 proach the time of hatching this color disappears and gives place to a dull leaden hue. 



The interval between the time of depositing and hatching of the eggs for the first 

 brood varies considerably, and the latter may be greatly retarded by inclement 

 weather. Usually, however, not more than ten days are consumed in maturing the 

 embryo within. The eggs of the summer brood seldom require more than one week 

 to hatch. 



Without check the offspring of the one female moth might in a single season (as- 

 suming one-half of her progeny to be female and barring all checks) number 125,000 

 caterpillars in early fall — enough to ruin the shade trees of many a fine street. 



A 



Fig. 85. — Hyphantria cunea: a, moth in posi- 

 tion on leaf laying eggs, side view ; b, eggs 

 enlarged. 



13 '/ //r'.(>\\\' 





w 



,^ 



Fig. 86. — Hyphantria cunea: a, dark larva, seen from side; &, light larva from above; c, dark 

 larva from above; d, pupa from below ; e, pupa from side ; /, moth. 



The larva (Fig. 86, a, h, and c). — The caterpillars just born are pale yellow with 

 two rows of black marks along the body, a black head, and with quite sparse hairs, 

 When full-grown they generally appear pale yellowish or greenish, with a broad 

 dusky stripe along the back and a yellow stripe along the sides ; they are covered 

 with whitish hairs, which spring from black and orange-yellow warts. The cater- 

 pillar is, however, very variable both as to depth of coloring and as to markings. 

 Close observations have failed to show that different food produces changes in the 



