244 QUARTERLY JOURNAL. 



common or clear-winged species, else I should not have failed to 

 have regarded them more particularly. 



All parts of this field of four acres were found to be infested 

 more or less with the wheat-fly, but they occurred most abundantly 

 along one of its sides, in the field adjoining which, wheat had been 

 grown the prece'ling year, which had been considerably injured by 

 this insect. Such a host of destroyers as were here found, and the 

 profusion of eggs that had been already deposited, strongly indicated 

 that it must have commenced appearing in its winged state many 

 days previous to this time. 



The wheat-fly may be met with daily, from the fore part of June 

 until so late at least as the middle of August. Although it congre- 

 gates in swarms about fields of wheat at the time they are in blos- 

 som, it also occurs in a great variety of other situations. It ofter 

 enters houses, upon the windows of which it may be observec 

 dancing along the panes of glass, sometimes in numbers. It ma] 

 also be taken among the grass of pastures, and of alluvial meadow 

 that have never been turned up by the plough. It is sometime 

 found in shady places, particularly along the margin of streams 

 associated with other minute species of Tipulidce in those dance 

 in which swarms of these insects so often engage. One specime 

 was met with on weeds, in the margin of an extensive and dens 

 forest, through which it must have made its way, or over an adjoin 

 ing lake a half mile broad, on the opposite side of which was th 

 nearest cultivated ground. 



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

 maining mostly at rest, or lurking about in the shade furnishe 

 towards the roots of the growing grain. In the twilight of evening 

 becomes active, and continues so perhaps during the entire night ; fc 

 before the morning sunrise it may be seen abundantly upon the win[ 

 though less agile than in the evening, as though it had now becom 

 somewhat wearied, or was rendered sluggish by the coolness an 

 dampness of the night air. Upon cloudy days, also, it resorts bi 

 little to its accustomed retreats. But it is during the evenings whic 

 succeed hot days of sunshine that it appears to be most busy an 

 full of life. If a field infested with them be visited with a lanter 

 at this time, such hosts as were little imagined to exist, will be foun 

 busily hovering about the grain, the most of them with wings an 

 legs extended, dancing, as it were, slowly up and down along tb 



