62 GUIDE TO INSECTS. 



female of Attdabus curculionoides (57) cuts oak leaves across the 

 middle, leaving the mid-rib intact. The terminal half then falls 

 back and is neatly rolled into a closed cylinder within which an 

 egg is placed. The larva lives and feeds within this shelter, 

 eventually falling to the ground to pupate. Rhynchites betulce (59) 

 treats birch leaves in a similar way, but the cell is sugar-loaf shaped 

 instead of cylindrical. 



Scolytidce, are small beetles which bore into trees, the larvae of 

 most of them feeding upon the soft layer immediately beneath the 

 bark. The borings of several species of Scolytus are shown. The 

 female drives a tunnel just beneath the bark and along it places her 

 eggs at regular intervals. Each little grub upon hatching proceeds 

 immediately to eat its way into the same layer, the tunnels increas- 

 ing in diameter with the growth of the inmates, but always keeping 

 separate, so that they become more and more oblique towards the 

 end of the colony. Curious and beautiful patterns are traced in this 

 way upon the surface of the wood. Certain other Scolytidaa live 

 socially within cavities in tree trunks, feeding upon fungi which 

 grow within the cavities and are even said to be cultivated by the 

 beetles. 



The Longicorns are wood feeders, attacking forest trees in every 

 part of the world. They sometimes emerge from wood which has 

 been in use for some time, and in which the larvae have been con- 

 cealed. Parts of the batten of a claret cask pulverised by Hylotrupes 

 lajulus are shown, together with specimens of the beetle. Two other 

 species shown sever small branches by gnawing a circular groove 

 around them. This is done by the female when laying her eggs. 

 The cut branch snaps off at the incision and the larva feeds within 

 it as it lies upon the ground. In a model against the East Wall are 

 shown branches of poplar attacked by Saperda populnea, the female 

 of which lacerates the bark with her mandibles and deposits an egg 

 at the injured spot. The larva enters the wood and feeds within the 

 swelling produced. 



The Ghrysomelidce are chiefly leaf feeders, and*some of them, like 

 the Colorado Potato Beetle (Doryphom IQ-lineata), are very serious 

 pests. That species, although it has been accidentally imported into 

 this country and the Continent, has hitherto not succeeded in estab- 

 lishing itself permanently. The Mustard Beetle (Phocdon cochlearice), 

 a common British species which destroys the leaves of mustard, is 

 shown in a model. Most of the members of this family possess 

 offensive juices which protect them from the attack of insectivorous 



