October, '17] DUNN: COCOANUT-TREE CATERPILLAR 481 



that do pupate in the trees usually attach themselves to the trunk of 

 the tree or outside wall of the nests, and seldom are found as chrysalis 

 inside the nests or in the pockets formed by the base of the leaves. 



The large numbers that leave the trees seem to select a variety of 

 places in which to pupate, such as beneath the overhang of roofs, under 

 boards on fences, on verandas, trees of different kinds other than 

 cocoanut palms, and in fact they are found in all manner of out of the 

 way places. The principal point that they appear to have in view is 

 a place that is dry and protected from the weather. 



When about to transform to a chrysalis the caterpillar fastens 

 itself to any under or side surface by the posterior end with a webbing 

 of fine silk and hangs head downwards. It seems to require about 24 

 to 48 hours for this transformation. During the first 12 hours the 

 caterpillars hang curled up and slowly contract longitudinally and 

 swell out at the upper or anal end. As the chrysalis forms inside and 

 draws away from the head of the caterpillar skin it leaves the lower 

 head end of the skin empty and collapsed. After about 12 hours 

 or more the larval skin starts to split lengthwise down the dorsal 

 surface and the round portion of the chrysalis beginsUo emerge and 

 by a sharp jerking motion soon endeavors to free itself from the cast 

 skin. This may sometimes be loosened from the chrysalis and fall to 

 the ground, or other times it may hang attached to the webbing of 

 silk, holding the chrysalis to the wall or place of attachment, and dry 

 up. 



After just pupating, the chrysalids often have a light red tinge to 

 their color which gradually darkens as they become more mature. 



The length of the chrysalis stage is from 14 to 17 days. At the end 

 of this period the shell splits and the adult butterfly emerges. 



Out of one lot, consisting of several hundred of these caterpillars, 

 that was collected and placed in separate jars and bred out in the 

 Laboratory, 53 per cent of the adults that emerged were females, and 

 the remaining 47 per cent males. Seventy-eight per cent of the males 

 had a 15-day chrysalis period, and 68 per cent of the females had a 

 16-day chrysalis period. This would tend to show that the males 

 emerge a little earlier than the females. The chrysalids that are late 

 in the season seem to have a day or two shorter period than when 

 pupating earlier in the season. 



For the first few hours after emerging the adult clings to the empty 

 chrysalis case until its wings become dry and straighten out, and it is 

 then ready to begin its existence as an adult. 



Since the eggs begin to form in the females during the chrysalis 

 stage at about the sixth day, the adults emerge with eggs almost 

 fully developed and it only requires copulation to fertilize them and 

 then they are ready to be deposited. 



