386 INSECTS INJURIOUS TO VEGETATION. 



to be a species of Enajrtus, 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 destruction of the slugs ; 

 and it is found to answer the purpose. It is probable that Mr. 

 Haggerston's almost universal remedy may prove to be still more 

 effectual. 



The saw-flies, though undoubtedly belonging to the order Hy- 

 raenoptera, 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 powerful jaws of the predaceous 

 tribes, nor the long and slender lower jaws and tongue of tnose 

 that subsist upon honey. They live but a short time, and their 

 food appears to be pollen, the tender parts of leaves, and some- 

 times the plant-lice and other soft-bodied insects frequenting flow- 

 ers. In the stiflhess of their upper wings, and the heaviness of 

 their flight, they somewhat resemble beetles, and, analogically, 

 may be said to typify the Coleoptera, or, in other words, they 

 may be called the beetles of the Hymenoptera. They will be 

 found, on comparison, to have some features in common with the 

 crickets, which, with the earwigs, are also the representatives of 

 the Coleoptera. Although they differ essentially from butterflies 

 and moths, the resemblance of most of their young to caterpil- 

 lars, in form and in habits, is very striking and remarkable. 

 Hence the saw-flies plainly show the relation existing between 

 the orders Lepidoptera and Hymenoptera, and serve closely to 

 connect them together. 



The next piercing insects to be described belong to the family 

 of Urocerid^, or horn-tails, so called because they have a 

 horny point at the end of the body. The Germans call them 

 wood-wasps. Their antenna are slender, and thread-like, or ta- 

 pering. They have a large head, convex before, and flat behind 



