176 ORDER DIPTERA. 



is, that in reaping or harvesting the grain, the straw is cut above the place where the larvse 

 or e^p are usually found ; and it would be well, in all cases where the fly is found, to 

 cut the straw higher than customary. Now if the stubble is turned under for the next crop, 

 a large proi^rtion of the eggs will mature, and the succeeding wheat-plants will form a 

 habitation for the forthcoming August brood ; but if the stubble is first burned, the eggs 

 will be destroyed, or but few will escape. The objection to this summary remedy is, that 

 it also destroys those little insects that prey upon the hessian-fly. I deem this a very light 

 objection, for the fire will destroy hundreds of eggs where the enemy of the fly would 

 devour one. Burning off the stubble, then, must be ranked among the best palliative means 

 for saving the wheat-crop. 



There are also two remedies having relation to the habitudes of the wheat itself, and to 

 its varieties. It appears to be established by observation that some varieties are less subject 

 to injury than others, or indeed that some are nearly fly-proof : this is one of the earliest 

 facts on record, and all experience hitherto has fully sustained it ; the straw of these 

 varieties being too siliceous to allow of a ready lodgment and home for the larva of the 

 fly. The other remedy here alluded to, rests on the practicability to push forward and 

 mature the plant sufficiently to give it strength to resist efifectually the injuries the stem 

 receives from the maggot in its flaccid state. High cultivation should be called to our aid 

 here, and it undoubtedly will prove a very efiicient safeguard : its efl'ects are twofold, as 

 exhibited in an augmentation of the power of the plant to resist injury, and in the produc- 

 tion of a better crop ; so that the remedy is not entirely lost, even if it does not succeed 

 in the way we wish. 



Objections have been made to the first two remedies above proposed : for instance, by 

 late sowing, the grain is liable to be winter-killed ; but would not this risk be greatly 

 diminished, or even obviated entirely, by drilling in the grain 1 The burning of the stubble 

 is objected to, because it destroys the parasites of the fly ; but this, as I have said before, 

 is scarcely an objection ; while for the utility of the remedy, we have the testimony of 

 Harris, Herrick and Hanaus, the latter of whom originally proposed it, and the two 

 former are entitled to the highest consideration as observers and men of science. 



Of the numerous applications to the grain crop, for the purpose of killing the insect 

 directly, I have no faith. Rolling the seed in plaster ; steeping it in various salts ; sowing 

 lime, etc. over the field of young wheat, are beneficial remedies in an indirect way : they 

 give vigor and strength to the plant, and hence are useful as palliatives. 



Cecidomyia tritici. Wheat- fly. 

 This species is very distinct from the hessian-fly : its habits sufficiently show this dif- 

 ference ; and the remedies which are in some degree palliative in the case of the hessian- 

 fly, are valueless against the Cecidomyia tritici. Among its peculiarities, some of the most 

 remarkable are that it deposits its eggs in the wheat-head, and undergoes its metamorphoses 



