412 The Moths and Butterflies 



pillars, trusting to the uncomfortable mouthful of hairs they offer their 

 bird enemies, travel conspicuously about in the open with a characteristic 

 nervously hurrying gait. Thus the Arctians become familiar to collector 

 and observer. 



The woolliest woolly bear is the larva, sometimes called "hedgehog," of the 

 Isabella tiger-moth, Pyrrharctia (Isia) Isabella (PI. VII, Fig. 3), common all 

 over the United States ; it is covered with a stiff furry evenly shorn coat black at 

 either end and red-brown in the middle, and is commonly seen in the autumn 

 traveling rapidly about in open places. It hibernates in larval stage under 

 loose bark or logs or sidewalks, and, after a brief activity in the spring, pupates 

 within a slight cocoon made up of silk and its own brown and black hairs. 

 The moth which issues soon is dull orange with the front wings variegated 

 with dusky and spotted with black; the hind wings are lighter and also 

 black-spotted; it expands 2 inches. The caterpillars feed on various plants, 

 sometimes becoming destructive, when in sufficient numbers, to black- 

 berry and raspberry bushes and to nursery stock. Lugger says that they 

 are especially susceptible to attack by muscardine, a parasitic fungus disease 

 much feared by silkworm-growers. "Hedgehogs" killed by muscardine are 

 found stiffly attached to their food-plants with a whitish powder over the 

 body at the base of the dense hair covering. 



The yellow bears, common caterpillars on the leaves of vegetables, 

 flowering plants, and fruits, distinguished by their dense but uneven coat 

 of long creamy-yellow, light or even dark brown hairs, are the larvae of the 

 beautiful snowy-white miller-moth, Spilosoma mrginica. The wings bear a 

 few (two to four) small black dots, and the abdomen is orange-colored 

 with three rows of black spots. The larvae pupate in the fall in cocoons 

 composed almost wholly of their own long barbed hairs, and the moths issue 

 in the spring. There is usually a second brood each year. This moth is 

 kept in check by many parasites, few other insects having to contend with 

 so many of these insidious enemies of their own animal class. 



The most destructive member of the family is the fall web- worm, Hyphan- 

 tria cunea, which makes the large unsightly silken "nests" in various trees, 

 both wild and cultivated, so familiar in late summer and autumn. The eggs 

 are deposited in regular clusters of 400 or more on the plum-leaves, and the 

 hatching pale-yellow larvae spin small silky web-nests close together which 

 finally get included in one large one. The full-grown larvae are pale yellow- 

 ish or greenish with a broad dusky stripe along each side; they are covered 

 with whitish hairs which rise from black and orange-yellow warts. They 

 often hang from the nest or branches by a long silken thread. They pupate 

 in crevices of the bark and other sheltered places on the ground, passing 

 the winter in this stage. The milk-white moths, sometimes with small 

 black spots on the wings, sometimes unspotted, issue in late spring or early 



