78 Studies on Life-history of Bombycine Moths. 



middle of the body (abdominal segments 2 to t) are much paler, being 

 of a brown flesh-color, though with no reddish tint ; among the pale 

 flesh-brown hairs are a few scattered black lateral and dorsal ones. 

 The tubercles are large, bearing nun)erous hairs. The head is uni- 

 formly of a pale horn color. 



On June 30th, the colors of the black and of the tawny-brown 

 hairs are now respectively more pronounced and dissimilar, so 

 that we have indicated the differences in color between the reddish 

 abdominal segments 2-7 and the bluish hairs of the rest of the body, 

 characteristic of the mature larva. A dorsal pale indistinct stripe 

 is present. 



Stage IV. — Length 15 mm. A specimen bred from the oak is 

 now almost exactly like the adult. The head is dark chestnut, and 

 the five succeeding segments are black; the tubercles and hairs of 

 the hinder edge of the 2d abdominal, and the whole of the three 

 succeeding segments (3-6) scotch-snuff reddish-brown or tawny, 

 exactly as in the full-fed larva, while the 8th to 10th segments are 

 black with black hairs and tubercles. On the 2d thoracic segment 

 are a few reddish hairs. A few hairs in front and on the hinder 

 end are nearly or quite twice as long as the others, which in general 

 are about two-thirds as long as the body. The thoracic feet are 

 black; the abdominal feet dark, with the plantaa flesh-colored. This 

 caterpillar remained alive and without molting till the 8th of 

 September. I saw several full-grown larvae September 8th. 



It appears from the above-stated facts that the characters of the 

 mature larvae, i. e., the dense hairs, those on the 3d-6th abdominal 

 segments being reddish, are indicated in stage III, and completely 

 appear in stage IV. 



The freshly-hatched larva of Spilosoma virginica (Fabr.). 



Eggs laid May 20th and hatched June 2d to 4th; mostly dead, 

 but one or two hatching June 5th. 



Larva just hatched. Length 2 mm. Body pale greenish; head 

 large, slightly wider than the body, dark chestnut-brown ; the two 

 .sides full and swollen, with a pale suture between. All the pilifer- 

 ous warts dark chestnut, conical, very distinct, contrasting with the 

 pale greenish body. Hairs blackish, very long, some of them over 

 one-half as long as the body. A faint crescent-shaped prothoracic 



