22 
account for this only by supposing ‘that these heads were just be- 
ginning to be protruded from their sheaths as the operations of the 
fly were closing for that year ; and hence confidently inferred that 
if that wheat had been sowed a few days later, it would have es- 
caped entirely, or a few days earlier, it would have been entirely 
destroyed. By a reference to my Farm Book, I find this crop was 
sowed April 26th, and cradled August 10th, but no note was taken 
of the time when it was in blossom. I must confess, however, that 
my observations the present scason have greatly diminished my 
confidence in the time of sowing as securing the crop from injury. 
Though I did not see the fly abroad until the 16th of June, it was 
then present in such swarms, and had already deposited its eggs so 
profusely, that I think it must have commenced appearing quite 
early in that month. It, moreover, continued to be abundant, until 
about the middle of July, and specimens were occasionally met 
with a month longer. Certainly if it is usual for it to be spread out 
over such an extent of time, it will be vain to rely upon the time of 
sowing, to insure a crop against its ravages. Some observations in 
the foreign accounts also throw light upon this subject. Mr. Shirreff 
says, in 1829 the fly appeared June 21st; ‘‘and from the vast numbers 
of them then seen, it is probable a few of them may have been in 
existence some days previous.” ‘Their eggs were seen June 23d, and 
must therefore have been deposited on the evening of the 22d. ‘‘ The 
flies were observed depositing eggs on the 28th, and finally disap- 
peared on the 30th of July, thus having existed through a period of 
thirty-nine days,” and depositing eggs during thirty-seven of these 
days. I know not how Mr. S. could be certain that the fly had dis- 
appeared for the season on the 30th of July, for his account is 
dated the first day of August. For a few days only after their first 
appearance, he tells us, they frequented the couch-grass as well as 
the wheat. Was not this because there was not at that time a suffi- 
cient quantity of wheat in bloom to accommodate the number of 
insects that were then out? And Mr. Markwick distinctly states 
that it was after the grain had been harvested, that he found the 
larve in the wild oats. Were not the parent flies then obliged to 
resort to this plant, because all the wheat had become mature ere 
they had completed depositing their eggs ? These facts certainly 
make it appear as though the fly is often abroad before the wheat 
commences blossoming, and continues till after it becomes mature. 
