15 



Life cycle of Tortrix viridana, L. 



By Alfred Sich, F.E.S. Beail Maij 12th, 1915. 



The common little green moth, Tortri.v riyidaua, L., is usually 

 such an abundant insect that entomologists can obtain all specimens 

 required without the slightest difficulty. No one therefore has pre- 

 viously had any need to breed this species, much less to rear it from 

 the egg. Consequently, when in 191-1 some questions were asked as 

 to its life-history, with the idea of combating its ravages, no definite 

 answers were forthcoming. It being then the middle of May, and 

 therefore too late to examine the earlier stages, a number of larvie 

 and pupae were collected, and from these a supply of ova were sub- 

 sequently obtained. Fortunately these hatched in the Spring of 

 1915, before the young larviE appeared in the open, so that the be- 

 haviour of the captives gave a key to the habits of the larvae in their 

 natural state. It was then not a great difficulty to find them on 

 the trees and to discover how they passed the rest of their lives. 

 The only point still left undiscovered is the position on the tree 

 where the eggs are laid. There is little doubt, however, that this 

 must be on the bark of the branches. There was no opportunity ia 

 1915 of watching the females in the act of ovi position. Such an 

 opportunity would, of course, settle the matter. Oak is no doubt 

 the chief foodplant of this species, and for that reason, as well as on 

 account of the abundance of the insect on this tree, no other kind of 

 tree was taken into consideration. 



In the South of England the moth flies in June. The males may 

 be seen in numbers on the wing around oaks in the late afternoon. 

 They soon lose their vivid green colour and become very bleached. 

 While the males are flying the females may be seen sitting on the 

 upper surface of the oak leaves. Their more restful habits enable 

 them to retain their colour for a much longer period. The males 

 seek the females among the foliage and, judging from captive speci- 

 mens, it seems probable that the moths remain together for several 

 hours, and that occasionally a moth of either sex will pair more than 

 once. In my opinion there is no doubt that the eggs are laid on the 

 bark of the branches of the oak, but I have not yet succeeded in 

 finding any eggs of this species in nature. They are not laid on the 

 leaves nor on the twigs of the first or second year's growth. 



The dulness of the newly-hatched larva lends colour to the sug- 

 gestion that it may have to travel along the dark oak twigs before 



