ENTOMOLOGY. 171) 



injuries suffered from its subjects are unimportant, arid 

 I might say, unknown. The voracious and tyrannical 

 dragon-fly, may perhaps destroy in its fury many species 

 of insects, which are of value to the husbandman ; but as 

 its instinct prom [its it to feed upon many noxious species, 

 it ought perhaps to be regarded as a blessing, rather than 

 a curse. The next genus, Ephemera, the spring-fly, al- 

 though its existence is continued but a day, affords a 

 valuable substitute to many farmers in Europe for manure. 

 Scopoli, the historian of the insects of Carniola, remarks 

 that the peasants in his neighborhood are dissatisfied, un- 

 less they can individually, collect at the times of their 

 appearance, at least twenty cart loads, to strew over 

 their grounds. The Hemerobius, or golden-eye, in its 

 larvae state, is of great value also, in the destruction of the 

 Aphides, or plant-lice. 



The fifth order has four membranaceous, naked wings, 

 and is called Hymeno/itera, from wnen, a membrane. This 

 order has been ranked at the head of the class by some 

 naturalists, on account of their admirable economy. The 

 gall-fly, saw-fly, ichneumon-fly, wasp, bee and ant, 

 are arranged by Linnaeus, in this order of insects. Some 

 genera are extremely injurious, while others are of im- 

 mense value. 



The Cynips, or gall-fly, when its larvae are deposited 

 in unusual numbers upon a leaf, must detract largely from 

 its nourishment : consequently, whole trees may, in some 

 seasons, suffer from their presence. The second genus, 

 Tenthredo, commonly called saw-fly, is the most dreaded 

 insect of this order its vulgar name is derived from the 

 instrument by which it makes an incision, in a leaf; this 

 instrument, is a double saw, which in using, the insect 

 first throws out one, then the other alternately, until a 

 sufficient incision is made; when they are both retracted, 

 and the egg is deposited from between them. Although 

 the larvae of this genus generally feed on the rose, and 

 the willow tree, our grain, vegetables and fruit trees, have 

 been at times, seriously injured. One species of these 

 larvae, which has received the name of slug-worm, and 

 which has been admirably described, its changes and its 

 injuries, by the late Professor Peck, in a volume of the 



