144 



FOREST ENTOMOLOGY. 



season they may be found in the Midlands about the end of May, 1 

 but more commonly in the middle of June. At the same season of 

 the year as we find the spangle gall, two or three other species of 

 Neuroterus may be found. 



2. Neuroterus fumipennis (Htg.) 



Gall on the under side of oak leaves, circular in outline, smaller in 

 size and brighter in colour than the spangle gall (fig. 135) ; but the 

 principal difference is that the spangle gall is raised in the centre and 



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Fig. 135. Galls of Neuroterus 

 fumipennis. 



Fig. 136. Galls o/Spathegaster tricolor. 

 (Drawn by P. J. Brown.) 



the outer edge lying flat on the leaf, whereas the species in question 

 has the outer edge of the gall raised and slightly depressed in the 

 centre. Thus the individual galls somewhat resemble a saucer. 



According to Adler, larval development does not begin until March 

 (by the time Neuroterus lenticularis has hatched), and the flies appear 

 about the end of May. The same authority says this fly is easily 

 distinguished from all the other species of Neuroterus. Size 2 mm. 

 Thorax dull black ; base of abdomen orange ; legs, including the 

 femora, orange ; wings, especially at the tips, smoky. 



1 May 27, 1895, in Cheshire. 



