54 THE ENTOMOLOGIST. 



NOTES ON OAK-GALLS IN THE QUERCETUM OF THE 



ROYAL BOTANIC GARDEN, KEW. 



By R. Allen Rolff,. 



Our British oak-galls are necessarily confined to the one 

 species of oak indigenous to the coimtr}^ but where numerous 

 species are growing in close proximity it is not surprising to find 

 that certain galls spread and flourish on other species than our 

 own, namely Quercus Rohur. Such has been the case in the 

 Quercetum here, and a few notes of the same are now offered to 

 the readers of the ' Entomologist.' 



Quercus Rohur, L. — This oak has been split up and made into 

 several species by different authors, but they can only be con- 

 sidered as well-marked varieties. DeCandolle, in his ' Prodromus,' 

 makes two subspecies, — jjefZimcMZaia, fruit-stalked; and sessiliflora, 

 fruit sessile, — arranging the varieties under them in accordance 

 with the presence or absence of a peduncle to the fruit; 

 intermediate forms, however, occur with peduncles of various 

 lengths. Q. pubescens he places under sessiliflora, as the fruit is 

 sessile ; but as there is a pubescent variety with pedunculate 

 fruit, and the amount of pubescence varies on some forms of 

 sessiliflora, I shall treat them as varieties only, enumerating the 

 galls found on each. 



Var. Q. PEDUNCULATA, Willd. 



Neuroterus nurnismatis, 01. — Common. 



N. lenticularis, 01. — Very common. 



N./wnipeymis, Hart. — Generally distributed, and fairly common. 



N. IcBviusculus, Schenck. — I have only found this gall on one small 

 tree ; two leaves are infested, the galls numbering seventy-nine ; two leaves 

 the previous year with nineteen galls. 



N. ostreus, Hart. — Fairly common. 



Spathegaster baccarum, L. — Common. 



Andricus curvator, Hart. — Common. 



A. inflator, Hart. — Not rare. 



A. tenninalis, Fab. — Common. 



Cynips Kollari, Hart. — Common. 



Dnjophanta divisa, Hart. — Not rare. 



D. scutellaris, 01. — Not rare. 



Aphilothrix gemmcB, L. — Fairly common. 



A. autumnalis, Hart. — Two specimens. 



A. callidoma, Hart. — Rare, on a small tree. 



Var. Q. Haas, Kotschy. 

 8. baccarum, L. — Not rare. 

 C Kollari, Hart. — Not rare. 



