74 Studies on Life-history of Bombycinp. Moths. 



longer than the body is thick; the shortest ones are of the sarnc 

 color as the longest. The spiracles are pale, surrounded with a 

 narrow black ring. The piliferous tubercles are pale, but mostly 

 speckled with dark at the origin of the hairs. 



The larval stages of Leucarctia acr^a (Drury). 



It feeds voraciously on plantain leaves, and makes a great quan- 

 tity of frass. The eggs were laid June 19th, at Brunswick, Me., 

 the larvae hatching June 25th, in the morning, their first act, after 

 breaking out, being to devour the shell. 



Egcj. — Diameter 0.6- 7 ram. Hemispherical, rather high, white, 

 with a coarsely pitted surface as seen under a triplet; under a 

 •^-inch objective the deep pits arc seen to be closely crowded, and 

 surrounded with smooth swollen polygonal edges; the pit itself 

 being rounded. The larva eats away the upper half of the shell, 

 the edge being scalloped, each scallop representing the cut made by 

 the jaws. 



Larva, stage I. — Length slightly over 2 mm. The body is pale 

 or somewhat dusky flesh-colored, without any reddish tint. The 

 head is shining black, large, wider than the body. The prothoracic 

 shield is well-developed, crescent-shaped, contracted in the middle, 

 the surface on each side gibbous ; dark chestnut. The piliferous 

 warts are rather large and quite convex. The two dorsal tubercles 

 of 2d and 3d thoracic segments bear tu'o hairs, the lateral ones 

 bearing each two hairs.. The abdominal dorsal tubercles all bear 

 but a single long spinulated hair, exce[)t the lateral ones, which 

 bear two small short hairs of unequal length ; all the subdorsal 

 warts bear but a single hair. Some of the hairs are nearly as long 

 as the body. The double dorsal row of small warts are rather 

 peculiar. The thoracic legs are chestnut, the abdominal ones of a 

 dusky flesh color. There are 2 sets of ungues on each abdominal leg. 

 It moulted June 30th to July 2d, the duration of the stage being 

 about 5 or 6 days. 



Stage II. — Length 5 mm. The head is, after it has fed a few 

 days, narrower than the body, chestnut-black; the clypeal and 

 labral region pale flesh The body is pale greenish, with yellowi.'^h 

 tints. The prothoracic ])late is now divided into halves. The 

 tubercles are dark, the hairs blackish '^1 he ilorsal and subdorsal 

 warts bear usuall}^ five hairs, one very long, the four others shorter 



