302 WHEAT MOW FLY ITS HISTORY. 



Myriads of small pale maggots crawling from the mow of wheat soon after it 



is placed in the barn; the kernels of grain shrivelled and dwarfish. 

 The wheat mow fly, Agromyza Tritici, new species (Plate 2, fig. 1). 



Several years ago a farmer in my neighborhood, soon after 

 gathering his wheat into the barn, found countless myriads of 

 small worms were crawling out of it, literally covering the mow 

 of grain and wandering away from it to every part of the barn. 

 These worms it is evident had just now completed their growth 

 and were crawling about in search of the moist earth, wherein 

 to bury themselves, to repose during their pupa state. It would 

 seem that some cause had made them later than usual in reach- 

 ing maturity; and had the wheat remained in the field a few 

 days longer, they would have escaped from it there, so generally 

 that no notice of them would have been taken, and the fact 

 would never have been known that such an army of insects had 

 had their subsistence upon this crop. 



Alarmed with the numbers of these worms, and fearing they 

 would perhaps wholly destroy the mow of grain, the proprietor 

 had the whole of it threshed immediately. I happened to visit 

 the barn as the threshed grain was being winnowed, when the 

 above facts were communicated to me. The heap of uncleaned 

 grain was literally alive with these worms and the cracks in the 

 floor were filled with them. The kernels of wheat appeared to 

 be shrunk in the same manner as when they have been infested 

 with the wheat midge. I put a number of these worms into a 

 small box, with some of the chaff and grain. Other engage- 

 ments diverted my attention from this subject and it was wholly 

 forgotten until many months afterwards, when, happening to open 

 the box, I found in it quite a number of small flies, which had 

 completed their transformations and perished in their confine- 

 ment. It therefore appears that it is by no means essential to 

 these worms to bury themselves in the moist earth, though that 

 is doubtless their natural habit. But if they can find any cre- 

 vice in the dry barn where they can stow themselves and lie un- 

 disturbed, it is all they require in order to complete their trans- 

 formations. 



The worms, according to my recollection, were much like the 

 little yellow maggots of the wheat- midge, but were of a dull 



