268 [Senate 



by the plow. It is sometimes found in shady places, particularly along 

 the margin of streams, associated with other minute species of Tipu- 

 lidcB in those dances in which swarms of these insects so often engage. 

 One specimen was met with on weeds, in the margin of an entensive 

 and dense forest, through which it must have made its way, or over 

 an adjoining lake a half mile broad, on the opposite side of which was 

 the nearest cultivated ground. 



The fly during the sunshine of day moves about but little, remaining 

 mostly at rest or lurking about in the shade furnished towards the 

 roots of the growing grain. In the twilight of evening it becomes 

 active and continues so perhaps during the entire night;" for before the 

 morning sunrise it may be seen abundantly upon the wing, though less 

 agile than in the evening, as though it had now become somewhat 

 wearied or was rendered sluggish by the coolness and dampness of the 

 night air. Upon cloudy days, also, it resorts but little to its usual 

 retreats. In short, it appears to be only the direct rays of the sun which 

 it avoids, for if a tree be standing in an infected wheatfield, the fly may 

 be met with in its shade, on the wing and depositing its eggs at mid- 

 day. Hence those parts of a field shaded by trees or an adjoining 

 wood, have been repeatedly observed to be severely devastated or even 

 entirely destroyed, when the other parts of the same field have been but 

 moderately injured. 



But it is during the evenings which succeed hot days of sunshine 

 that the fly appears to be most busy and full of life. If a field infested 

 with them be visited with a lantern at this time, such hosts as were 

 little imagined to exist, will be found busily hovering about the grain, 

 the most of them with wings and legs extended, dancing, as it were, 

 slowly up and down along the ea.rs, intently engaged in selecting the 

 most suitable spot where to deposit their eggs. This being found, the 

 insect alights, and standing upon the outer glume or chaff of the ker- 

 nel, curves its abdomen so as to bring the tip in contact at right angles 

 with the surface of the glume. It now toils industriously to insinuate 

 its ovipositor through the scale, which is not accomplished till after a 

 considerable exertion. Sometimes even, the scales having probably 

 acquired too much maturity and hardness to be pierced by the tiny 

 stinger which the fly protrudes, it is foiled in its efforts, and, as if 

 vexed at its ill success, spitefully jerks its wings apart and darts away. 

 This occurrence, however, is rare. And having penetrated with its 



