24 



were fully developed, larvae were feeding upon the ripening 

 grains, and later on, when the oats were fit to carry, there 

 were quantities of pupa?- imbedded in the grains. 



Larva? of the Frit Fly have also been found in the late 

 autumn upon winter oats and rye, so that the insect is at its 

 work of mischief during the greater part of the year. As late as 

 the end of November in self-sown oats in fields that were badly 

 infested this summer they were seen to be abundantly present. 



DESCRIPTION AND LIFE HISTORY. 



The fly is very small (Plate III. c). It is shiny black 

 with black legs, arid the feet, or tarsi, are yellowish to brownish 

 yellow. The wings are translucent, with brown shades. 

 Taschenberg says that the eggs are reddish, and laid singly on 

 the underside of the leaf. The larva (Plate III. a) is first noticed 

 in the bulb, or crown, upon whose juices it feeds. It is yellowish 

 white, not quite the eighth of an inch long, and without legs. Its 

 head is furnished with formidable hooks, and its tail end with two 

 spiracles. The pupa is reddish brown, somewhat shining, having 

 at its extremity two curious knobs. (Plate III. 6.) It seems, 

 from the fact that larvae were found in the spring in the bulbs, in 

 the joints in the summer, in the oat grains later on, and in young 

 winter oats and rye plants in the autumn, that there is a con- 

 stant succession of broods depending upon the state of the food 

 plants and the weather. Many pupse are can-led into the ricks, 

 and may be taken into the yards and fields in the oat straw, 

 and in the cleanings from the threshing machines. Some of the 

 pupae fall to the ground, and either remain there during the winter 

 or change to flies, which lay eggs on winter oat and rye plants. 



METHODS OF PREVENTION AND REMEDIES. 



No direct remedy can be devised for this attack. The larvae 

 cannot be reached by liquid or powder applications. When it 

 is noticed that oat plants turn red in their early stages, and 

 have a stunted appearance, they should be manured with nitrate 

 of soda or sulphate of ammonia, to force them along rapidly. 

 This should be done in dry seasons especially, when oat plants 

 are usually inclined to stand still in May even when there is 

 no attack of insects. 



To prevent this attack it would be desirable to plough infested 

 oat stubbles soon and deeply after harvest, and not to sow 

 winter oats and rye near infested fields. When threshing oats 

 from infested fields it would be desirable to burn the chaff, 

 cavings, and cleanings. 



PARASITIC FLIES. 



Parasitic flies of two distinct species came from pupae of the 

 Frit Fly placed in a glass-capped case. Five of these came from 

 20 pupa?. 



