238 



OAK. 



The gall of the Neuroterus lenticularis is distinguishal:)le 

 from the four other kinds of Spangle Gall found in Britain by 

 its somewhat larger size, and also by being raised in the 

 centre and hairy. It sometimes occurs in great quantities on 

 the backs of Oak leaves, but rarely to an extent to cause 

 serious damage. 



In the above short notes I have not alluded to the varia- 

 tions of form which may exist, or may be supposed to exist, 

 in alternate generations of various of the Ci/nijndce, as these 

 are rather points of curious speculation than serviceable for 

 general use. 



Oak Leaf-roller Moth. Tortrix viriiiana, Linn. 



Tortrix viridana : Moth ; caterpillars hanging by their threads, slightly 

 larger than life ; rolled Oak-leaf. 



The caterpillars of this moth cause serious injury from time 

 to time in our Oak woods and forests, especially in the south 

 of England, by feeding in such vast numbers on the young 

 leaves as to strij) the trees of their foliage, and thus retard the 

 growth of the first shoots, and injure or entirely ruin the 

 acorn crop of the season. 



The eggs are laid during the summer or autumn of the 

 year preceding the attack of caterpillars, either on or in the 

 leaf buds, or on the boughs (opinions differ as to the precise 

 spot) ; but in the following spring, when the Oak leaves are 

 appearing, the caterpillars hatch, and sometimes swarm in 

 myriads over the infested trees on many acres of ground. 



The caterpillars are at first greenish grey, or lead-colour, 

 afterwards dull green, with head and tail-patch black, and 



