224 FOREST ENTOMOLOGY. 



worst year for these caterpillars that he remembered, he passed 

 through a wood composed of Q. sessiliflora in which, though it had 

 been attacked by the caterpillars, they had left off, evidently either 

 poisoned or starved. He also quotes a resident in the Forest of 

 Dean, who, writing in 1881, says: 'It was strikingly evident last 

 summer that the Q. rohur jJedunculata, or old English oak, was 

 attacked by blight (1 caterpillars) more severely than Q. r. sessili- 

 Jfura;' and Mr Baylis, who now has charge of Dean Forest, writes 

 to me on the subject as follows : ' I can confirm the statement that 

 the larva of the green oak moth defoliates Q. pedunculata very much 

 more than Q. sessiliflora, and I think the reason is this : the latter 

 is the first to come into leaf, and the leaf has time to get fairly tough 

 before the caterpillar has reached its most destructive stage, which 

 is about the time that Q. pedimndata is coming into leaf. I have 

 frequently noticed this fact, that the oak with more decided pedun- 

 culate characters is almost invariably attacked rather than the 

 other.' " 



As regards remedies for this species, it is most difficult to know 

 what to suggest, and it therefore affords a very good case in point as 

 showing how difficult it is to cope with a real forest pest on a large 

 scale. 



TORTRIX RIBEANA (Hub.) 



This species is a general feeder on many kinds of trees, and fig. 221 

 on hazel may be taken as a typical example of its injuries. The 

 foliage is often entirely eaten by the larvae of this species. At first 

 they riddle the leaves very much indeed, and take advantage during 

 the day of the uneaten portions of the under side of the leaf for 

 shelter. Finally, they often denude the trees of the entire foliage, 

 and pupate in the soil. 



The larva and moth of this species are often very variable in 

 colour and markings, and as there are several species doing similar 

 damage, it would be well to verify the respective species by hatching 

 out the moths from larvae making injuries on hazel after the manner 

 of the illustration given. 



Penthixa pruniana (Hub.) 



It often happens that isolated specimen thorns on lawns, and also 

 patches of trimmed thorn hedges, show almost complete defoliation 



