322 ORDER LEPIDOPTERA. 



Aegeridae. 



( See Plate XX vi, figs. 1, 3.) 

 The peculiarilies of the insects of this family are, the translucency of their wings, elon- 

 gate form of body, and the absence or rather deficiency of scaly covering when compared 

 with the SpHiNGiDJE. They bear some resemblance to the Hymenoptera : their antenn» 

 are simple, and often terminated by a small pencil of hairs. The insects are interesting, 

 from the fact that they are highly injurious to trees, especially fruit trees. They are fleshy 

 grubs of a cylindrical shape ( fig. 4), with brown heads and strong jaws ; but unlike many 

 of the larvie of this order of insects, they have no caudal horn. They have the ordinary 

 true six legs, eight ventral feet, and two feet at the extremity of the abdomen. 



The different species feed upon dlfiFerent kinds of trees ; some upon the currant, moun- 

 tain ash, etc. The most destructive one is the .Mgeria exitiosa of Say, which preys upon 

 the peach-tree. The egg is deposited upon the bark near the root, and, when hatched, the 

 young penetrates to the wood, when it either continues its course into the wood, or burrows 

 between the wood and bark : usually, however, it proceeds into the soft wood, sometimes 

 just below the surface of the soil, at other times above. In either case, such is the extent 

 of the injury inflicted, if allowed to maintain possession, that the tree is killed. Probably 

 the peach-trees in this country have suffered more from the ^geria, than from all other 

 insects put together. 



Mgeria exitiosa. (Plate xxvi, figs. 1 - 5.) 



Fig. 5, female ; 1, male ; 4, larva ; 2 & 3, cocoon and pupa. 

 Color steel-blue. Wings of the male transparent, and bordered behind with steel-blue : 

 palpi, feelers, edges of the collar, and shoulders yellow ; smaller than the female. 

 Female, steel-blue : wings steel blue ; hindwings transparent : middle of the abdo- 

 men marked with an orange-colored ring or belt. Expanse of wing, 1^ inch. 

 Mr. Harris remarks that the segeria does not confine its attacks to the peach-tree, but 

 may be found also on the cherry, its larvae being developed in the black knotty branches 

 of the tree. It does not always locate itself at the base of the trunk of the peach-tree, but 

 frequently bores into the limbs, in which case much less injury is done to the whole tree. 

 The infested tree may be discovered by the presence of the dust and cuttings which the 

 larvse throw out around the roots ; but it is often necessary to remove the surface soil, in 

 order to detect their presence. 



The mode that is most successfully pursued for extirpating these insects, is to cut them 

 out with the knife, avoiding the sound parts of the tree as much as possible. A wire thrust 

 Into the burrows may destroy the larvae, without cutting the tree. 



