498 INSECTS INJURIOUS TO VEGETATION. 



wort ( Tephritis Asteris). Its body is about one fifth of an inch 

 long; it is of a light yellowish brown color, with paler legs; 

 the wings are broad, rounded at the tip, and clouded with brown 

 in large spots, forming three wide, irregular bands across them. 

 Many of the smallest flies, belonging to several other groups, 

 are placed near the end of the order. One of them has a head 

 like a hammer-headed shark, short and very wide, with large 

 globular eyes on each side of it. This little insect has been 

 found in considerable numbers, flying near the ground, on the 

 edges of banks. It is the Sphyracephala hrevicornis of Mr. 

 Say, and is figured and described in the third volume of his 

 " American Entomology." The w^ell-known cheese-maggots 

 are the young of a fly (Piophila casei), not more than three 

 twentieths of an inch long, of a shining black color, with the 

 middle and hinder legs mostly yellowish, and the wings trans- 

 parent like glass. Some minute flies, belonging to a family 

 called OsciNiD^, are found to be very injurious to wheat, rye, 

 and barley, in Europe. One of them {Oscinisfrit), a shining 

 black fly, with yellowish feet, and measuring about one tenth 

 of an inch in length, lays its eggs in the blossoms of barley, 

 the grains of which afterwards perish in consequence of the 

 depredations of the maggots of this fly; and Linnffius states 

 that a tenth part of the produce of the barley in Sweden is 

 thereby annually destroyed. The larvae or maggots of Oscinis 

 lineata, Chlorops pimilionis, Chlorops glabra, and other flies 

 allied to them, live within the lower part of the stems of wheat, 

 rye, and barley, thereby impoverishing the plants, and causing 

 them to become stinted in their growth. They are rather 

 larger insects than the frit-fly, and they have black and yellow 

 stripes on the thorax. It is highly probable that some of these 

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

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

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

 diflferent 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 scientifically examined and described. From 

 the somewhat vague accounts that have been given of them, 



