REPORT OF THE SOCIETY 125 



The above figures were obtained from moths confined on apple branches 

 by means of large cheese cloth bags. The total number of eggs laid by the 

 individual female probably ranges from forty to one hundred and fifty. 

 The usual number is in the neighbourhood of one hundred. 



The life of the adult budmoth is very short. The female dies shortly 

 after she has deposited her eggs. When males and. females of the same age 

 were mated in confinement the males usually died before the females. 



Development of the Eggs. — The eggs generally hatch in eight or nine 

 days; the writer in the course of his investigations has observed the develop- 

 ment of many batches of eggs and in one case only was the period of deve- 

 lopment slightly under six days. The longest period observed for their 

 development was ten and one-half days. 



Development of the Larva. — The larva in hatching eats its way out of 

 the egg shell, which it immediately abandons. It if hatches on the upper 

 side of the leaf it crawls round to the under side. The newly hatched 

 larva feeds for a very short while before beginning to spin its tube of silk, 

 almost invariably next the midrib or some other large vein. The tube is 

 enlarged as the insect grows; the excrement of the larva and the hairs from 

 the leaf are added to the silk. 



It is difficult to follow the development of the larva because of its 

 habit of feeding concealed in a tube. In order to obtain material for study 

 the writer mated several pairs of budmoths on a potted apple and placed 

 the latter outside the window of his laboratory so that conditions might 

 be as nearly natural as possible. In this way 150 larvae which all 

 hatched on the same day were obtained, and a few of these were removed 

 each day for study. 



The larvae hatched on July 9th; at this time they were 1.03 mm. long 

 and the diameter of the heads was .228 mm. The first moult took place 

 on July 14th. The diameter of the head was then .304 to .342 mm. and the 

 length 1.9 mm. The second moult on July 20th increased the diam^eter of 

 the head to .39-. 437 mm. and the length of the body to 3.04 mm. On July 

 26th there was a third moult, and some of the larvae moulted for the fourth 

 time on August 13th. It was thus possible to follow the insect through the 

 first four instars during the summer and to ascertain the duration of these 

 instars which was as follows: — first instar, 5 days; second, 6 days; third, 

 6 to 8 days; fourth, 18 days. 



It was more difficult to determine the number of moults in the spring 

 and so the method described by Dyar and previously used by Slingerland 

 in determining the number of moults in the bud moth was employed. It 



