40 FIRST REPORT ON ECONOMIC BIOLOGY. 



When present in large numbers they do much damage to foliage 

 trees and will also attack fruit trees. 



LlFE-HlSTORY. 



The moth makes its appearance about the middle of June, and 

 the female deposits her eggs on the underside of the leaves in groups 

 varying in number from twenty to sixty. Owing to their large size 

 they are somewhat conspicuous. When looked at from above they 

 are seen to be rounded and pearly-white, while towards the base they 

 are greenish, and flat beneath. 



In ten or twelve days the larvae hatch out, and undergo the first 

 moult about ten days later. In early life they are gregarious, after a 

 time they separate, but throughout this stage they are always met with 

 in groups. From the middle to the end of September they generally 

 become full-fed, when they commence to descend the trees, either by 

 falling or crawling. They pupate immediately beneath the tree 

 usually in the soil, but may often be found beneath fallen leaves, and 

 remain in this stage until the following June. 



The pupa is a deep mahogany-brown, smooth, glossy, about an 

 inch long, and provided with two spines at the apical or pointed end. 

 It is not enclosed in a cocoon. 



PREVENTIVE AND REMEDIAL MEASURES. 



Shaking or jarring the infested boughs has been recommended 

 (Ormerod), but except in their young state they are difficult to 

 dislodge. In September I found it almost impossible to move them. 

 Before jarring, tarred bands of hay should be placed around the trunks 

 so as to prevent the larvae ascending again. 



A good plan is to spread a few spadefuls of gas lime around the 

 trees at the end of September, when they commence to descend the 

 trees prior to pupating. Fowls turned on to the land about this time 

 will also destroy both larvae and pupae. 



The large size and bright colouring of the larvae render them 

 very conspicuous, and on small trees hand-picking is very effective. 



For fruit trees spraying with arsenate of lead should be carried 

 out. 



