ANDRICUS NODULI. 65 



The larvae pupate in the gall. The imagines emerge during 

 April and May. 



Inquilines,^ Nos. 17, 132. 



This gall is mostly globular in form, but it varies 

 in size, and also in shape from that of a cherry to 

 that of a walnut. It is found generally on bush and 

 scrub oaks. 



" Its whole surface is covered with stiff, stalky, or 

 fibrous projections, which stand out radiately, and 

 terminate in a rusty-red papilla. In section it exhibits 

 a hard texture with numerous egg-shaped cavities ; in 

 these live the larvge, without being separately enclosed 

 in an inner gall " (Mayr). 



Mosley recorded it in 1892 occurring in Whitley 

 Woods, Yorkshire. 



Andricus noduli, Hartig. 

 (Plates XII, IX, div. B.) 



Andricus nodvli, Mavr, Marshall, Adler, Midler, Walker, Moslej ; 

 A. tr ill neat us, Hartig, Cameron. 



English name of gall. — " The Knot Grail." 



Position of gall. — Beneath the bark of twig and in leaf petiole. 



Manner of growth. — Separate, gregarious, glabrous, concealed. 



Colours. — White, very pale green, pale brown. 



Average dimensions of a mature specimen. — Length, 

 2 mm. ; breadth, 1 mm. 



May be sought during the months of June to August. 



Growth is complete by the end of July. 



The typical condition of the gall is unilocular and unilarval. 



The larva pupates in the gall. The imago emerges during 

 August and September. 



Parasites, Nos. 56, 103. Inquilines, Nos. 17, 110, 128, 145. 



Alternate agamic generation : ApMlothrix radicis, Fabr. 



Upon reference to Plate IX, div. B., it will be seen 

 that the autumn-winter condition of twigs and leaf 

 petioles containing many of these galls is very con- 

 spicuous on account of the swollen and nodulose 

 appearance. It is only when many galls close to each 



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