THE METAMORPHOSIS OF THE SPHINGINA. 95 



are bereft of scales, except upon the nervures, upon the margin, 

 and in some scattered spots. With the essential character of the 

 Lepidoptera, they have almost the physiognomy of the Hymcnop- 

 tera, or bee tribe. 



It is rather curious to notice how the insects of one order 

 mimic those of another with which they have no family con- 

 nection. The strangest part of the matter is, that the habits of 

 the SesiidcB are not in the least like those of the very violent- 

 tempered insects whose uniform they wear. 



The SesiidcB, although moths, fly in the hottest sunshine, and 

 often rest on trees and shrubs, in order to lay their small round 

 eggs. The caterpillars have an elongate, and almost cylindrical 

 body, and they live in the interior of the trunks of trees, of 

 branches, roots, and even in some fruits. Pale, and almost with- 

 out the least colour, like beings which never see the light, 

 there is no difficulty in determining that they are wood-eating 

 larvae. 



One of these wasp-like moths is called the bee-shaped Sesia 

 {Sesia apifonnis), and it may be seen flying to and fro amongst 

 the poplars by the river side, or running with much agility upon 

 their trunks. This moth, which is classified by Mr, Stainton 

 under the genus Sphecia, lays its eggs on the bark of poplar 

 trees, low down and near the ground. When the caterpillars 

 are hatched they gnaw the bark, and each endeavours to pene- 

 trate the tree by excavating a tiny gallery. The larvae live a 

 long time, and drill holes of a considerable size, doing much 

 harm to the trees. They are enabled to do this quietly and 

 efl*ectually, for instead of only living for a few weeks before 

 their metamorphosis into the chrysalis, and having jaws fitted 

 for browsing the tender shoots and leaves, their caterpillar life 

 lasts two years, and their masticating apparatus is strong, and 

 admirably fitted for its purpose. It is very remarkable that 

 they should only flourish upon those trees which have been 

 injured ; and it would appear that the abundance of the sap of 

 perfect and healthy poplars is too much for the excavators. 

 An examination of the caterpillar proves how admirably it is 

 adapted for its peculiar method of life, and how perfectly help- 

 less it would be upon a tender succulent plant. The legs are 



