OF EPPING FOREST. 14! 



Gall. 



Appears on the imder-surface of the oak leaf (diameter 

 2-3 mm.) Colouv : Yellowish to reddish. Shape : Irregular to 

 circular, cup-shaped and pointed in the centre ; few or no hairs 

 present. Numerous on the leaf. 



Imago. 



Colour : Black. Thorax and Head : Smooth 'and shining. Abdomen : 

 Compressed and elongate. Ajitenticc : Dark brown, 2 basal joints may be 

 yelloA\ish. Legs : Dark brown. Apices of all the joints yellow. Wings : 

 Hyaline. 



(2.) Sexual Generation IIa. Neuroterus albipes 

 (Schenck). Inquiline. Synevgus apicalis (Htg.) 



Gall. 



Appears on the margins of the leaves, causing indentations, 

 and in some cases stunting them. Shape : Oval, may be some- 

 what pointed at the apex. Sessile on the leaf margin. Colour : 

 Yellow to yellowish green. 



Imago. 



Colour : Black. Antennce : Brownish. Basal 4-5 joints yellow. Third 

 joint slightly curved in the male. Thorax: Smooth and shining. Ahdoinen : 

 Shining and compressed. Ovipositor : Testaceous. Legs : Usually very light 

 yellow in colour. Coxae and bases of femora dark. Wings \ Hyaline, nervures 

 pale. 



Account of Generation Cycle. 



The Neuroterus laeviusculis galls fall to the ground, like 

 N. lenticularis, in the Autumn. Moisture is also necessary for 

 them if they are to reach maturity. 



Asexual flies emerge from them as a rule about the end of 

 March. These insects prick the oak buds at the end of March 

 or the beginning of April ; the resulting galls, N. albipes, which 

 are small and hard, appear in May. 



From the galls of N. albipes, sexual flies emerge at the end of 

 May, though often not until June. These flies oviposit on the 

 under-surfaceof the young and tender leaves, and in about three 

 weeks the galls of Neuroterus laeviusculis again appear. 

 OCCURRENCE IN EPPING FOREST. 



The Neuroterus laeviusculis gall often has the edges curled over, 

 and may be very irregular in shape, in many cases bearing a 

 great resemblance to Neuroterus fumipennis. First appearance 

 noted August 12th. This gall was not so common as the 

 preceding. Neuroterus albipes, however, was very abundant, the 

 first appearance I noted being on May i8th. This gall I found 

 in a variety of situations, both on the petioles and on the leaves 

 themselves, causing them to become indented and to curl up. 



