Co lour- Changes in Leaves 395 



Sycamore (Acer pseiido-platanus) . 

 First changing to yellow, then brown. In its' ally the 

 common maple [A. campestve) the golden yellow tint is very 

 pronounced and more quickly assumed. (For markings 

 induced by parasitic fungi see other frames). 



Group II.— CHANGES INDUCED BY INSECT PARASITES. 

 (1) Leaf Miners. 

 Holly {Ilex aquifolium). 

 Holly leaves mined by the larva of a minute fly [Chvomatomyia 

 ilicis) which burrows beneath the upper cuticle and causes the 

 familiar reddish blotches. The corresponding lower surface 

 bears a very slight yellow discoloration. Apparently no harm 

 results to bushes attacked by this fly. 



Oak. 



Oak leaves mined by the larvae of a species of Lithocolletis (a 

 genus of leaf-mining moths) causing more or less oval whitish 

 spots on both surfaces. All members of the genus make very 

 similar mines in leaves of various trees and pupate in them. 

 Bees and beetles (infrequently) and flies also mine leaves. 



Bramble. 



Bramble leaves mined by the larvae of Nepticula aurella, a 

 minute golden-brown moth. The burrow begins as a mere 

 thread and widens as the grub increases in size. Commonly 

 seen on leaves of young brambles. The leaf is usually reddish 

 around the burrow. 



Beech. 



Beech leaves which have assumed the brown tint of autumn 

 but retain isolated patches of green. Each patch is occupied 

 by a living larva or pupa. In the upper series may be seen 

 the hairy tubular galls of Hermomia peligera, a minute fly. 

 Below are the mines of two small moths ; on the left the 

 serpentine burrow of Nepticula titigrella, on the right the oval: 

 mine on the underside of the leaf of Lithocelletis- faginella.: . 



