222 PROTECTION AGAINST INSECTS. 



b. Life-history, etc. 



The ? lays her eggs one by one on the under surface of unde- 

 veloped beech leaves, etc., biting holes for the purpose under 

 the epidermis, near the mid-rib. The larva hatches in the 

 month of May and bores in the leaf-parenchyma either 

 towards the terminal point of the leaf, or sideways, forming a 

 winding tunnel which continually increases in size till it 

 becomes a large patch. The parts which have been eaten, at 

 first whitish, become finally brown. Pupation takes place 



Fig. 86. Beech-leaf attacked by O.fagi, Gyll. (Natural size.} 

 a Commencement of larval mine by a gallery, which widens at b into an irregular 

 space, c Pupa in a bladder-like cocoon, d Holes of various sixes gnawed by the 

 beetles. 



near the border of the leaf, between the upper and lower 

 epidermis of the area which has been eaten by the larva. 



In June the beetle emerges, and passes the winter under 

 the dead leaves on the ground. 



When the larvae of this insect are abundant, the foliage of 

 the beech trees appears reddish-brown, just as if it had been 

 frozen by a late frost. 



The beetle shortly after emergence has been known to feed 

 on various substances ; for instance, fruit (cherries, raspberries, 

 gooseberries), cauliflowers; it also pierces the capsules of beech 

 nuts, causing them to open before the seed is ripe. In the 

 early summer it riddles the beech leaves with small holes, and 

 gnaws the female flower-buds. 



