274 
On the Wheat Midge. 
some degree apparent as the insect selects the opportunity of depositing 
them when the ear of the wheat is onlv partly exposed, and, in almost 
every instance, before it is fully developed ; as during that period it will 
be fouud moist and clammy : for, although some flies may be seen upon 
the wheat -ears that have been some time exposed, it rarely happens that 
maggots are produced, and then only whilst a certain degree of atmos- 
pheric moisture is found to prevail ; it is from this circumstance that 
the ears of the wheat are found infected on one side only, and invariably 
upon that side that first appears. The time selected by them is from 
four to six o'clock, or sunset, and from six to eight o'clock in the 
morning ; during those periods they may be seen, — if prevalent, from 
one to five or six upon nearly every ear of wheat in the act of depositing 
their egois, with their heads uppermost and their ovipositors inserted 
between the chaff of the wheat. 
In some seasons the flies are found prevalent only upon the early 
wheat, and in others upon the later wheat, and it rarely happens that 
both are attacked extensively in the same year. 
In some years the ichneumon flies prevail, and the eff"ects of the wljeat- 
midge are, in some degree, frustrated by them ; but in warm and dry 
seasons, wheat comes rajjidly into ear, and soon advances into so forward 
a state as to preclude injury from their attacks; whilst, on the other 
hand, in moist, cool, and backward seasons, it comes more slowly into 
ear, giving the flies greater opportunity of extending their mischief; 
and this is one of the operating causes why wheat is more productive in 
eatly and dry seasons, than in late and moist ones. 
I have this year inspected the wheat (whilst coming into ear) 
minutely, and have, up to this time, seen fewer insects than in previous 
years ; upon investigating a field this evening (June 8th) more than 
one half of the ears of wheat are fully developed. I have not seen 
altogether more than three or four flies, and those diminutive, and appa- 
rently but just produced from the chrysalis ; in the same space (if 
investigated) last year, a thousand would have been found, as scarcely 
an ear could be then found with a less number than five or six flies at 
one time upon it. 
I am led to conclude, from these observations, that in early seasons 
the wheat comes into ear before the flies are produced, and that the 
later wheat in such seasons only is attacked; and that invariably the 
very early wheat is not so liable to be attacked as the later ; that the 
flies in ordinary seasons are in greatest number from the 10th to the 
20th of June, and rarely seen at all in numbers before that time ; and that 
probably the warmth of the season may vary the time of their coming into 
life, so as either to anticipate or succeed the earing of the wheat in par- 
ticular districts. From the habits of the insect it is to be inferred that it 
cannot travel far, and that those flies produced in situations where wheat 
was grown the preceding year would perish, unless a succeeding crop of 
wheal should be grown so as to enable them to perpetuate their species 
in the succeeding year. 
I address these observations to the Council, hoping that the subject 
may be thoroughly investigated under its direction ; for although, 
with our jjresent knowledge, but little chance appears of mitigating the 
