80 ON SOME LEPIDOPTEROUS LARV^ 



constantly being enacted in Nature — an insect remarkably 

 well protected from the general perils to which most larvse 

 are exposed, falling a victim to another which is specialized 

 for the express purpose of preying upon it. These little 

 Sesias or Clear wings are very seldom seen or recognised, as 

 they so closely resemble flies and wasps as to be easily 

 passed over ; but the larvse of some of the species are very 

 abundant in certain localities, notably the Currant Clear- 

 wing, which inhabits the twigs of most old currant bushes. 



Any damage of which these larvse may be guilty is quite 

 eclipsed by that which is done to trees by the great larvae of 

 Cossus ligniperda (the Goat Moth), Zeuzera jyyrina (the 

 Wood Leopard Moth), and others. The first mentioned has 

 caused the destruction of many fine trees, nearly all our 

 forest and fruit trees being liable to its attacks. Its formid- 

 able jaws enable it to penetrate very hard wood, whilst its 

 long course of .existence in the larval state, between three 

 and four years, causes the damage done by each individual 

 caterpillar to be very considerable. In some cases seventy 

 or eighty living larvae have been found in one tree, and 

 when this occurs the powerful goat-like smell of the larva, 

 which has earned for it its English name, is very noticeable. 

 There is a story, believed by Barrett to be authentic, of a 

 goat-moth larva which was shut up in a wooden cigar-box 

 and placed inadvertently on a piano, being found inside the 

 instrument next morning ; a clean-cut hole through box and 

 piano showing the path which the larva had taken. It was 

 at one time believed that this caterpillar was the Cossus. of 

 the Romans, and was eaten by them as a delicacy : this 

 belief has given the generic name of Cossus to the insect. 

 It is now generally held, however, that the Roman Cossus 

 was the grub of a large beetle, and it certainly seems onlj- 

 charitable to the Romans to acquit them of fondness for 



