188 LEAF-MINING INSECTS 



by Miss Helen Reed of the head of two little leaf-beetle 

 miners show the differences in extension backward of the 

 f rons and of the hind angles of the epicrania, and the flatten- 

 ing and widening of the mouthparts that are the signs of 

 progressive adaptation. Figure 56 shows greater backward 

 extension of the frons. 



The mines of the Coleoptera are chiefly of the blotch type. 

 Often the mine is blister-like, making a large pocket within 

 the leaf. Dibolia makes long tortuous mines which seldom 

 become blotched except when many larvae are mining in 

 the same leaf. Hippuriphila and Phyllotreta make short 

 linear or serpentine mines while Orchestes starts as a linear 

 mine but later changes to a blotch-mine. 



FAMILY BUPRESTIDAE 



In this great family of metallic wood-boring beetles, 

 there are known leaf -mining members of five genera. About 

 half a dozen species of the large European genus Trachys 

 have long been known to be leaf -miners. One species of 

 the Old World genus Aphanisticus, A. consanguineus, mines 

 the leaves of sugar cane in Java. Several species of the 

 cosmopolitan genus Pachyschelus are miners, but all are 

 very insufficiently know r n. Certain species of Brachys, 

 Pachyschelus and Taphrocerus, have been carefully studied 

 in North America, and these will serve to illustrate the 

 family. We select one that is a miner in leaves of oak, one 

 in Desmodium and another in bulrush. 



Life History 



The egg. The eggs are laid singly upon the surface of a 

 leaf. They are soft, and when covered with a transparent 

 secretion that overspreads them, they settle down upon the 

 surface in a low dome-shaped form. Often they are further 

 covered and hidden by lumps of excrement. In hatching 



