266 OUR INSECT FRIENDS AND FOES 



upon the trunk and main branches of the trees. 

 The caterpillars vary a good deal in colour 

 during their growth, and also when full grown. 

 Just after emerging from the egg they are 

 yellowish-green, with a faint white stripe along 

 the back ; while later they may be green, greyish, 

 or greenish-grey, or blackish. They are very 

 typical in their movements, taking firm hold 

 with the front legs, and then drawing the back 

 part of the body up to the front legs, so that the 

 insect's body is formed into a loop ; the front 

 legs then let go their hold upon the twig, the 

 caterpillar stretches its body forward along the 

 branch, and, grasping it, again brings the hind 

 part of its body close forward. The insect thus 

 proceeds by a series of loops, and it is from this 

 peculiar and characteristic mode of progression 

 that the larvae of the Winter Moth, in common 

 with the larvae of other Geometers, are popularly 

 known as " Loopers." 



Many are the insect foes of our forest trees, 

 some attacking the foliage, others the roots, 

 trunk, bark, and branches, so that no part of a 

 tree can be said to be safe from the ravages of 

 some winged or creeping insect. Very often 

 during April one may see numbers of tiny 

 beetles about a sixth of an inch long, of various 

 dusky shades of blackish-brown, and with 

 stout, rather oval-oblong bodies crawling about 

 on the ash trees. If we watch one for a little 

 time, we shall be able to see that it is busily 

 engaged in boring a hole in the bark of the tree, 

 and in a very short time it disappears from view. 

 This is the Ash-bark Beetle (Hylesinus fraxim), 



