268 INSECTS INJURIOUS TO VEGETATION. 



camp* lackey caterpillars of Europe, for which they have been 

 mistaken. From the first to the middle of June they begin to 

 leave the trees upon which they have hitherto lived in company, 

 separate from each other, wander about awhile, and finally get 

 into some crevice or other place of shelter, and make their co- 

 coons. These are of a regular long oval form, composed of a 

 thin and very loosely woven web of silk, the meshes of which are 

 filled with a thin paste, that on drying is changed to a yellow 

 powder, like flour of sulphur in appearance. Some of the cater- 

 pillars, either from weakness or some other cause, do not leave 

 their nests with the rest of the swarm, but make their cocoons 

 there, and when the webs are opened these cocoons may be seen 

 intermixed with a mass of blackish grains, like gunpowder, ex- 

 creted by the caterpillars during their stay. From fourteen to 

 seventeen days after the insect has made its cocoon and changed 

 to a chrysalis, it bursts its chrysalis skin, forces its way through 

 the wet and softened end of its cocoon, and appears in the winged 

 or miller form. Many of them, however, are unable to finish 

 their transformations by reason of weakness, especially those re- 

 maining in the webs. Most of these will be found to have been 

 preyed upon by little maggots living upon the fat within their 

 bodies, and finally changing to small four-winged ichneumon 

 wasps, which in due time pierce a hole in the cocoons of their 

 victims, and escape into the air. 



The moth of our American lackey-caterpillar is of a rusty or 

 reddish brown color, more or less mingled with gray on the mid- 

 dle and base of the fore-wings, which, besides, are crossed by two 

 oblique, straight, dirty white lines. It expands from one inch and 

 a quarter, to one inch and a half, or a httle more. This mothf 



* The castrensis, oi camp-caterpillar, has a narrow broken white line on the top 

 of the back, separating two broad red stripes, which are dotted with black ; the 

 sides are blue, with two or three narrow red stripes ; the head and first ring are 

 not marked with black dots ; there is no wart on the top of the eleventh ring; and 

 the belly is white, marbled with black. 



t A short but very accurate account of this insect may be found in the late Pro- 

 fessor Peck's *' Natural History of the Canker Worm," printed at Boston, among 

 the papers of the " Massachusetts Society for promoting Agriculture," in the year 

 179G. Professor Peck seems to have been aware that it was not identical with 

 the JVeuslria, but he forebore to give it another scientific name. It is figured, in 



