Cecidomyia bursaria. 



These pretty little galls may invariably be found wherever 

 Glechoma liederacea is growing. Seldom will any considerable 

 patch of this plant be free from attack. One needs to look 

 closely at first in order to see them, although they are neither 

 hidden as regards their position on the leaf, nor so inconspicuous 

 as might be imagined. When removed from their surroundings 

 they are very distinctive. During growth they are the same 

 colour as the leaf, and consequently are not easily discerned. 

 When nearing maturity many specimens show a reddish tinge 

 at the apex ; but when mature they all turn a dull brown 

 colour, and very soon afterwards fall to the ground, leaving 

 small circular holes in the leaf During their vigour they are 

 not easily removed from the leaf without tearing away a portion 

 of it also. Looking at the underside of the leaf, the position of 

 the galls may be determined by depressions, each of which is 

 surrounded by a slightly lighter shade of green. The surface of 

 the gall is thickly covered with short hairs, each of which, 

 when viewed under magnification, is seen to be growing from 

 the apex of a conical swelling. A single cylindrical-shaped 

 larva occupies each gall. The interior of the gall is quite 

 smooth, but at its base a large number of long, pointed 

 hairs appear. 



The illustration is of specimens gathered at Hastings by 

 the author. 



