THE FALL WEB-WORM. 19 



of seven feet by actual measurement. If a nest be torn open, the 

 inmates in a short time repair the breach. 



I have examined the nests upon different kinds of trees to see whether the differ- 

 ence of food produced any variation in the color of the caterpillars, but could dis- 

 cover none. This is the more remarkable as they are not a particularly uniform spe" 

 cies, the insects in the same nest varying from a pale buff or brownish yellow to 

 a dull green, but having in both cases somewhat of a grayish tint, produced by a dense 

 sprinkling over the whole body of minute black points and lines. This intermixture 

 of black is the densest on the upper side, so as to constitute a broad blackish dorsal 

 stripe ; but many individuals are scarcely darker on the back than on the sides. 

 Drs. Harris and Fitch both describe the larva of Hyphantr'ta Itxtor, as having a black 

 head. I have seen a few black-headed individuals in nests both on the apple and 

 the hickoiT, but nearly all of them have heads of a clear amber-brown color. The 

 upper lip and the basal joint of the small antennae are pure white, constituting quite 

 characteristic marks, irrespective of all other variations. There are fire inconspic- 

 uous whitish lines extending the length of the body, one on the middle of the back 

 and two on each side. The upper part of the neck is black or dark brown, divided 

 through the middle by the white dorsal line. There are twelve pale orange or amber 

 colored tubercles on each segment, the two middle dorsal and the lowest lateral ones 

 being smaller than the others. The two larger dorsal tubercles are sometimes black, 

 both in the darker and lighter colored individuals. Each tubercle emits a tuft of long 

 hairs which are usually rusty-white, but in some specimens bright-ferruginous. 



Many kinds of caterpillars conceal themselves, or at least remain 

 stationary through the day and feed only in the evening or night. 

 In this way, no doubt, they escape to some extent the notice of 

 insectivorous birds, which are almost all diurnal in their habits. 

 The caterpillars of which we are now treati-ng are strictly noctur- 

 nal feeders. They remain in the oldest and densest part of their 

 nests through the day, and notwithstanding their long fast, they 

 do not venture out till it is quite dark. In order to witness them 

 at their work I have been under the necessity of examining them 

 by candle light. 



The Fall Web-worms, as these caterpillars are usually called, 

 have not heretofore been regarded as holding more than a third 

 rate rank in the catalogue of noxious insects. Yet, judging from 

 my observations the past season, I should suppose them to be upon 

 the increase. I saw the apple trees much disfigured by them 

 through the middle portions of the Slate, and also in my own 

 neighborhood ; and a correspondent of the American Entomologist, 

 writing from Massachusetts, remarks that they have been unusu- 

 ally abundant in that part of the country. They appear so late in 

 the season, not making much show till alter the first of August, 



