186 LEAF-MINING INSECTS 



mines Scirpus while Pachyschelus is a miner on Quercus, 

 Lespedeza and Trifolium. The Curculionidae confine 

 themselves to woody plants. The Chrysomelidae mine 

 chiefly in herbaceous plants although Zeugophora and 

 Chalepus occur for a large part as miners on the woody 

 plants. Microrhopala is found entirely as a miner on 

 asters and goldenrods. 



The larvae of Coleopterous leaf-miners parallel those of 

 Lepidoptera, without attaining quite so high a degree of 

 specialization. The body becomes flattened, with bulging 

 lateral expansions of the abdominal segments. The legs 

 dwindle or disappear, and the head becomes wedge-shaped 



Fig. 56. Heads of two mining leaf-beetle larvae. A, Chalepas; B, 

 Zeugophora. 



— depressed, with thin, flat mouthparts forming the front 

 margin of the wedge. The mouth swings upward to a 

 horizontal position and the frons extends to rearward be- 

 tween the side pieces of the epicrania. The latter are pro- 

 longed backward into the front of the prothorax where 

 strong muscles attach to them. By means of these the 

 head in feeding is moved up against fresh leaf tissue, while 

 the body is held stationary on its paired supports. Thus 

 movements of the head forward and backward (in and out 

 of the front of the prothorax) guide the jaws into position 

 favorable for food-getting. The accompanying drawings 



