59 
OAK. 
Oak Leaf-roller. Tortrix viridana, Stephens. 
Tortrix viridana. 
Moth; caterpillars hanging by their threads, slightly larger than life ; 
rolled oak-leaf. 
The Oak leaf-rollers are small caterpillars which do injury some¬ 
times over a great extent of woodland by feeding on the leafage of the 
Oak when young and tender, to such an extent as to strip the trees, 
and consequently greatly retard the year’s growth. 
The caterpillars hatch (at the time the Oak leaves begin to appear) 
from eggs which have been laid in the previous season. They are at 
first lead-colour or greenish grey. When full-grown they are about 
half an inch long, of a dull green, with dusky spots. They have the 
power of letting themselves down by silken threads, and may be seen 
in hundreds swinging in the air in infested trees, until they are either 
eaten by birds or return up their threads to the leafage. When full- 
fed—that is, towards the end of May—they turn to chrysalids either 
in tubes, which they have formed by rolling up the tip of the leaf and 
spinning it with threads into a kind of cylinder, or, if leafage fails them, 
to roll up or spin together, they wander away and turn to chrysalids 
in crannies of the bark of the trunks or boughs. From these 
chrysalids small moths of the shape figured above, with light green 
fore wings and hind wings of a brownish or silver-grey, come out 
about the end of June. 
Mr. W. J. Allsebrook, writing early in the summer from Wollaton, 
Nottingham, mentioned that large numbers of the Oak trees in the 
surrounding woods were denuded of their foliage by severe attack of 
green leaf-rolling caterpillars. He noted further that the caterpillars 
produced very pretty green moths, and that the trees were full of 
