270 Transactions. 



■5th stadium : Spiracles oval, brown. Subsegmentation on abdominal seg- 

 ments. 1 to 7. Pile thick but very minute. Body of equal width through- 

 out, slightly flattened dorsally and ventrally. The head is medium-sized, 

 somewhat square in shape ; clypeus small and distinct, possessing 4 minute 

 setae ; either cheek has 7 setae, the area included by the eyes bears 4 with 

 a 5th more remote ; mandibles serrate, with 5 points. 



Development of Larval Markings. 



1st stadium : General colour light green. Head light green with light- 

 brown mouth parts ; eyes black. Has a conspicuous brown spiracular 

 line. Tubercles light-coloured. 2nd stadium : Broad medio-dorsal stripe 

 of dark green. Spiracular stripe dark brown to black. 3rd stadium : A 

 light-brown stripe extends from either side of the base of the clypeus to 

 the top of the head, but they are some distance from the central facial 

 suture. 4th stadium : A very narrow white subdorsal line appears on either 

 side of the broad medio-dorsal stripe. Cheek-stripes ochreous and very 

 conspicuous ; while a third short thick stripe occupies the central portion 

 of the clypeus. The tubercles are still light in colour, excepting iv, which 

 is included in and is of the same colour as the spiracular band. 5th stadium, 

 (full-grown) : General colour green, ventral surface light. The narrow 

 white subdorsal stripes are margined on either side by a pinky area. 

 Tubercles black. Head-markings very strong, as in last stadium, the facial 

 markings extending across the prothorax, where they are black. Suranal 

 plate and upper portion of anal prolegs black. Before spinning the whole 

 body assumes a rosy hue. 



Variation in Larva and Imago. 



The Larva. — Here there is not much variation, chief instances being the 

 absence of the spiracular lines and cheek-stripes, and in the coloration of 

 the tubercles. There appears to be a variety which is, when full-grown, 

 larger (1^-in. to \\'m. in length), greener in colour, and not having such 

 marked subdorsal lines. This may be explained sexually. 



The Imago. — A certain amount of variation occurs in size and colour, 

 some specimens being brighter in the shades of brown than others. 



Table of Periods. 



Period of incubation from fifteen to twenty-two days, or longer. 

 1st stadium: fifteen days; length on hatching, ^ in. 2nd stadium : thirteen 

 days ; length after 1st moult, -jfe in. 3rd stadium : thirteen days ; length 

 after 2nd moult, -jfc in. 4th stadium : twelve days ; length after 3rd moult, 

 ^r in. 5th stadium : twenty-one days ; length after 4th moult, -^ in. 

 Larva, full-grown, fin. to ljin. in length; length before pupating, h in. 

 only ; duration of spinning, about two days ; duration of larval life within 

 the cocoon, four to five or more days ; duration of pupal existence, fifty 

 days (winter months). 



Habits. 



The young larvae on hatching do not eat the empty shells, but almost 

 immediately start climbing. At first they are very active, and able to crawl 

 long distances, betaking themselves to the innermost leaves of the cabbage- 

 tree, where they are wont to congregate together on the upper but inner 

 surface of the loose outer leaves forming the heart spike of the tree. Through- 

 out the first four stadiums their method of feeding is to scoop long channels 



