532 HYMENOPTEEA. 



in their cocoons, and it is probable that birds also prey 

 upon them when on the trees, both in the slug and the 

 winged states. Professor Peck has described a minute ich- 

 neumon-fly, stated by Mr. \Vestwood to be a species of 

 Encyrtus, that stings the eggs of the slug-fly, and deposits 

 in each one a single egg of her own. From this, in due 

 time, a little maggot is hatched, which lives in the shell of 

 the slug-fly's egg, devours the contents, and afterwards is 

 changed to a chrysalis, and then to a fly like its parent. 

 Professor Peck found that great numbers of the eggs of 

 the slug-fly, especially of the second hatch, were rendered 

 abortive by this atom of existence. 



Ashes or quicklime, sifted on the trees by means of a 

 sieve fastened to the end of a pole, was recommended, by 

 the late Hon. John Lowell, of Roxbury, for the destruc- 

 tion of the slugs ; and it is found to answer the purpose. 

 It is probable that Mr. Haggerston's almost universal rem- 

 edy may prove to be still more effectual. 



The saw-flies, though undoubtedly belonging to the order 

 Hymenoptera, depart from the general characters thereof 

 more than any other insects in it. They are more dull 

 and heavy in all their motions ; they have not the power- 

 ful jaws of the predaceous tribes, nor the long and slender 

 lower jaws and tongue of those that subsist upon honey. 

 They live but a short time, and their food appears to be 

 pollen, the tender parts of leaves, and sometimes the plant- 

 lice and other soft-bodied insects frequenting flowers. In 

 the stiffness of their upper wings, and the heaviness of 

 their flight, they somewhat resemble beetles, and, analogi- 

 cally, may be said to typify the Coleoptera, or, in other 

 words, they may be called the beetles of the Hymenop- 

 tera. They will be found, on comparison, to have some 

 features in common with the crickets, which, with the ear- 

 wigs, are also the representatives of the Coleoptera. Al- 

 though they differ essentially from butterflies and moths, 

 the resemblance of most of then young to caterpillars, in 





