TORTRIX V1RIDANA. 



338 



2. Tortrix viridana, L. (Oak Leaf-roller), 

 a. Description. 



Moth with wing-expansion of 18 to 22 mm. ; fore-wings 

 uniformly light green, and hind-wings light grey; whitish 

 fringes to all the wings. 



Caterpillar 15 mm. long, with 10 prolegs, at first greenish 

 grey, afterwards dull green, with head and anal flap hlack, 

 with warts on the back. Pupa 11 mm. long, slender and 

 black. 



c 



f 



Fig. 169. Tortrix viridana, L. 

 a Moth, b Caterpillar suspended by a thread, c Pupa. 



I). Life-history. 



The moth flies during daytime at the end of June and 

 the beginning of July. The eggs are laid singly or in little 

 clusters on the already bitten buds of the oak, and pass the 

 winter there. The caterpillars appear in April and May, and, as 

 pupation approaches, spin threads by which they let themselves 

 up and down from the branches ; they pupate usually at the 

 beginning of June, on the twigs of the trees which have 

 been attacked, generally in the upper leaves, which they roll 

 together, and also in bark-cracks. 



Generation annual. Everywhere tolerably common, and 

 sometimes present in enormous numbers. Very destructive 

 to foliage in oak-forests in the south of England. 



