418 INSECTS INJURIOUS TO VEGETATION. 



species, or other Oscinians, with similar habits, may be found in 

 the stems of wheat aad other, grains in this country, and perhaps 

 also in the ears. Several kinds of small flies, evidently different 

 from the Hessian and wheat flies, have often been observed here, 

 in fields of grain, when the plants are in flower ; but their history 

 has not yet been investigated, and the insects have not been scien-, 

 tifically examined and described. From the somewhat vague ac- 

 counts that have been given of them, it is evident that they are 

 much too large for any of the parasitical insects which attack the 

 larvae and eggs of the Hessian and wheat flies ; and they appear 

 sometimes to have been mistaken for the latter. In an extract 

 from a paper by Mr. Worth, on the Hessian fly, mention is made 

 of a pale yellow worm (maggot), about three sixteenths of an inch 

 long, having been found by him within the stalks of wheat near 

 the root, where its presence was detected by a swelling of the 

 part attacked. This was probably the larva of one of the Oscin- 

 ians. A careful examination of all the insects that inhabit our 

 fields of grain is very much wanted. 



The various insects, improperly called bot-bees, are two- 

 winged flies, and belong to the order Diptera, and the family 

 CEsTRiD^, so named from the principal geYius in it. Bot-flies 

 do nt)t seem to have any mouth or proboscis ; for although these 

 '.parts do really exist in them, the opening of the mouth is ex- 

 tremely small, and the proboscis is very short, and is entirely con- 

 cealed in it ;-so that these insects, while in the winged state, do 

 not appear to be able to take any nourishment. They somewhat 

 resemble the Syrphians in form and color, and in the large size of 

 theirheads ; but the eyes are proportionally small, and there is a 

 large space between them. The face is swollen or puffed out 

 before. The antenna are Very short, and almost buried in two 

 little holes, close together, on the forehead.- The winglets are 

 large and entirely cover the poisers. The hind-body of the fe- 

 males ends with a conical tubcj^bent under the body, and used for 

 depositing the eggs, which the insect lays whilst flying. The lar- 

 vae, or young of bot-flies live in various parts of the bodies of an- 

 imals. They are thick, fleshy, whitish maggots, without feet, 

 taoering towards the head, which is generally- armed with two 

 hooks ; and the rings of the body are surrounded with rows of 



