THE CANADIAN ENTOMOLOGIST. 47 



on the 2nd, 3rd, 4th and 5th segments, exist small blue tubercles tipped 

 with double spines. On the 1 2th segment, alternating with dorsal and lateral 

 rows, there are four blue tubercles, with a circle of six black spots near 

 their base, and a circle of four spines and one central on the dorsal 

 tubercles, and a circle of four spines on the laterals. In line with the 

 dorsals, two blue tubercles with five black spines, two of which in some 

 cases have nearly disappeared. 



True legs, greenish yellow, with black incurved claws ; pro-legs, green- 

 ish-yellow. 



Spiracles narrowly eUiptical, with pearly centres and black margins. 



Antennas, cream-colored, tipped with brownish, and having two dark 

 kidney-shaped spots near their base. Upper lip, pearl-colored and deeply 

 cleft; lower lip, similarly colored; palpi, short, hairy, and marked with dark 

 brown blotches ; jaws, pearly at base, and dark broAvn for the anterior 

 two-thirds. 



General color above, greenish blue; on the sides, pea-green, and of the 

 same color below. 



In many cases, the lateral and sub-lateral tubercles are a beautiful 

 pearl color, which appears to be due to the character of the food, for it 

 is a noticeable fact that the majority of the caterpillars which exhibit this 

 color-change, are found feeding upon the leaves of the common plum 

 (Pncmcs domestica). 



July 2 1 St — The larvae commence to spin their cocoons. This requires 

 a period ranging from three to four days. While the operation is in pro- 

 gress, a slight incision is made through a cocoon, which is instantly 

 repaired. Three times is the experiment performed, and as many times is 

 the cocoon mended. But the fourth time the caterpillar seems to take 

 no notice of the rent^ or, even if it does, it is unable to make good 

 the damage by reason of the lack of necessary material. The cocoon 

 being completed, the remaining efforts of the larva are spent in the rup- 

 ture and separation of the epidermis, which is eventually thrust into the 

 lower part of the cocoon. This is effected in about six days. The 

 process is precisely similar to that which takes place in moulting. 



Caterpillars in confinement, particularly in empty boxes, become 

 exceedingly restless, and wander about for several days, as if in quest of 

 something. This is especially noticeable in larvae which utilize the leaves 

 of the plants upon which they feed for cocoon purposes Where the box 



