131 



duction would relieve the orange-grower of the necessity of so much ex- 

 penditure to bring about the same result. Just as we employ cats to 

 kill off mice and ferrets to kill rats, so in economic entomology it be- 

 hooves us to encourage the entomological enemies of our insect foes, 

 especially in cases like the present, where there is a feasible method 

 promising good lesults in the introduction. 



THE HESSIAN FLY. 



(Ceeidomyia destructor Say.) 



This is a fragile midge belonging to the Diptera and to the family 

 Cecidomyidfe, and you will get a very fair idea of its general color and 

 appearance by recalling the common mosquito. It is one of the insects 

 most destructive to Wheat, Rye, and Barley. At the j)resent season it 

 is found in what is known as the flax-seed or jiuparium state. This is 

 the hardened larval skin inclosing the quiescent larva and ultimately 

 the pupa. These puparia are more or less hidden in the base of young 

 wheat plants and the perfect flies issue as soon as we get settled spring 

 weather, and in fact are issuing in southern latitudes at the present 

 time. The sexes are easily distinguished by the simpler antenna of 

 the female as compared with those of the male, by the more robust ab- 

 domen and extensile ovii:)08itor. She deposits her eggs between the 

 ribs of the blades generally near the base ; the young larvfe hatching 

 therefrom suck the substance of the stalk and imbed themselves more 

 or less fully within it. There are two broods annually, and in southern 

 latitudes a tendency to a third one. Few insects have more often been 

 treated of or more fully written about than this, and an added inter- 

 est has lately been given to it because of its recent introduction into 

 England. The species has long been known to occur upon the conti- 

 nent of Europe and the prevailing belief has been that it was intro- 

 duced therefrom into the United States during the Eevolutionary war 

 by Hessian troops. It was first announced in England some two years 

 ago by Miss. E. A, Ormerod, consulting entomologist of the Royal Ag- 

 ricultural Society, and it has proved more or less injurious and rapidly 

 extended during the past two years, so that at the present time it is 

 found on most j>ortions of the eastern coast extending up into Scotland. 



In North America the species has constantly, since the first announce- 

 ment of its appearance on Long Island, spread farther and ftirther west 

 with the westward movement of the center of wheat culture, so that at 

 the present time it may be said to extend over nearly the whole wheat 

 area of the United States, except perhaps the extreme northwestern 

 and the southwestern limits, where the excessive dryness of the atmos- 

 phere, in the one case, and the excessive heat of summer, in the other, 

 have proved, so far, obstacles to its successful multiplication. For a 

 long time it was unkuow n on the Pacific coast, but during the past three 

 years it has been quite injurious in parts of California. 



