ATHALIA SPINARUM. 309 



curled up in a semicircular form inside. On the fifth 

 day it escapes. 



This is about its normal rate of progress if the 

 weather be warm, but if, on the other hand, it be wet 

 and cold, the development is retarded considerably, 

 taking six, seven, or even twelve days, according to the 

 temperature. If the weather be very unfavorable many 

 of them are destroyed. 



When developed, the larva eats its way through the 

 shell, and then through the part of the leaf which 

 encircles the eggs. It eats at first the upper epidermis, 

 the portions eaten out being noticeable as little brown 

 patches, which are " partial perforation of the leaf 

 covered with the round cuticle of the upper surface." 

 When it quits the egg it is about half a line long, and 

 of a whitish colour with a black head. According to 

 Newport it does not eat the egg shell which remains 

 in the cavity. In three days it is double its original 

 length. At this period, according to the same author, 

 if it has to descend to the ground to search for a more 

 suitable leaf or for any other reason, it aids its descent 

 by means of a silken thread which it attaches to the 

 leaf and drops down by its aid. When older it does 

 not possess this faculty. It moults for the first time 

 on the fifth day after leaving the egg. In all it moults 

 three times, each at an interval of from five to seven 

 days before it becomes fully fed and is ready to form its 

 cocoon. 



After leaving the egg the larva is white with two 

 black dots on the head; but soon the body becomes 

 darker and the head quite black. When the larva is 

 about fully grown the head is narrower than the second 

 segment, shining black, and covered with a few short 

 hairs. Each of the body segments is divided into 

 several folds, and smooth and shining, without any 

 hairs. The upper part to the spiracles is black, on 

 each side is a longitudinal slate-coloured spot ; then a 

 row of black, mostly double oblong spots. The legs 

 are slate-coloured ; the abdominal legs are black 



