38 BRITISH GALLS 



caused by the presence of the larvae of Neuroterus tricohr. 

 These galls are whitish, and covered with erect white hairs. 

 They appear in June, and mature in July. The wasps 

 emerge towards the end of that month, and prick the under 

 surface of the leaf. The cupped spangle galls result 

 (Fig. 4, 6; a magnified section is seen at Fig. 15). This 

 gall is sometimes confused with that of N. laeviusculus, but 

 there should be no difficulty in diagnosis if the sections are 

 carefully compared. The wasps which emerge are known 

 as Neuroterus fitmipennis. Adler observes : " They are very 

 active little flies . . . continually running from side to 

 side and flying from one shoot to another." 



There is an attractive-looking gall which sometimes 

 resembles a large ripe cherry, which appears in September 

 on the under surface of Oak leaves (Plate XXII., Fig. 6). 

 It is noteworthy that in 1910, which was not a favourable 

 year for Oak galls, it was very abundant in many districts ; 

 I noted it in enormous numbers on fallen leaves in Woolmer 

 Forest. Its vivid tints are chiefly seen in bright summers ; 

 in the dismal summer of igio the great majority were 

 yellowish-green. The colour is retained for a considerable 

 time after the leaf has fallen and withered (Fig. 7). The 

 wasp that emerges from it is the Dryophanta* folii (Fig. 8). 

 It usually bores the canal for emergence some time before 

 leaving its home, the outer skin of the gall remaining 

 unbroken. It oviposits in the adventitious buds at the 

 base of the trunk. According to Adler, only one egg is laid 

 in each bud. The gall which results is small, 2 to 3 mm. 

 long, of a beautiful dark violet colour, with a velvety 

 appearance (Fig. 5). These galls appear about the end of 

 April, and the wasps emerge towards the end of May. 

 They are the Dryophanta Taschenbergi, and were at one time 

 placed in the genus Spatkegaster. 



Fig. 3 on the same plate shows the under surface of an 

 Oak leaf with two striped pea galls and three common 

 spangle galls. The striped pea gall is easily identified by 

 * Dryophanta = Diplolepis of modern German authorities. 



