OF EPPING FOREST. 



153 



Andvicus testaceipes. Not plentiful. I found galls both on the 

 petiole and mid-rib of the leaf. 



First appearance noted, June 15th. 



(12.) Agamic Generation. II. Andricus corticis (Linn.) 



Inquiline. Synevgus incrassatus (Htg.). 



Gall. 



Found on the oak trees in places where the bark has been 

 injured, as when a branch has been sawn off or broken by- 

 wind. The gall is covered over in a thin sappy yellowish 

 rind, which afterwards falls off and leaves the gall exposed. The 

 larval chamber is sunk deep in the wood, the upper half, which 

 projects, being shed at maturity. The punctured rims then 

 plainly mark the presence of the galls. 

 Imago. 



Colour: Brownish black. Anfe?iitae : Dark brown, base reddish. Thorax'. 

 ]\Iay be sHghtly hairy, dark brown and smooth. Abdomen : Lighter in colour 

 than the thorax. Legs : Reddish brown. 



(12.) Sexual Generation. IIa. Andricus gemmatus 

 (Adler). 

 Gall. 



Small, only 2 mm. in length. Appears in the leaf axil or 

 growing from axillary buds. The apex of the gall only may 

 appear. I have found this gall on the leaf as well as in the bud, 

 when the shape is oval, the rind smooth and thin, and the apex 

 may be narrower. Green to brown m colour, though I have 

 sometimes found it quite red. Often it is very similar in appear- 

 ance to N. albipes. I have also found it attached to the 

 petiole of the leaf. 

 Imago. 



Colour : Black, shining. Antennae : Brownish black, base paler. Thorax : 

 Dull black. Abdo7nen : Dark, with brownish red ventral surface, Legs : 

 Yellowish red. Base of femora dark, but much lighter in colour in the male. 



Account of Generation Cycle. 

 The flies emerge from the A. corticis galls in April and May, 

 and lay their eggs deep in the bud. The resulting gall. A, 

 gemmatus^ appears in June, and the insects emerge in July or 

 August. I have never seen the insects of the sexual generation 

 engaged in ovipositing. This takes place in injured parts of the 



