708 
life; and it is unlikely, unless in rare cases, that 
the brood is ever lost in consequence of a want 
of synchronism in the maturity of the insect and 
the plant which is to form the nursery for its 
young.” Still, though the whole brood may 
never be cut off by anachronism between the 
plant and the insect, the numbers of it may there- 
by be very materially diminished; and though a 
farmer, in any infested district, or after any 
disastrous season, ought never to rely solely or 
mainly upon the producing of such an anachro- 
nism as a preventive, he may at least regard it 
as an auxiliary of sufficient possible Sed 
to be worthy of his attention. 
Remedies or preventives directed inimediately 
against the life or operations of the perfect fly 
were recommended by Kirby as most likely to 
prove successful. “ By a set of experiments first 
made upon a small scale,” says he, “ the intelli- 
gent farmer may possibly find out some method 
that will prevent this insect from laying its eggs 
in his wheat. These should commence as soon 
as the ear begins to quit the foliwm vaginans or 
hose; and they ought to be continued till the 
germen is impregnated, or, to use the rural 
phrase, the wheat is off the blossom. Perhaps 
fuigations of gobacco or sulphur, if made when 
the wind is favourable, might render the ear 
disagreeable to this insect.” But either fumiga- 
tions of anypguch kind, or medicated aspersions, 
or any oth née Be plications which might be sug- 
gested, in order to he made on a sufficiently ex- 
tensive scale to produce decided effect, would 
probably cost almost as much trouble and ex- 
pense as they could be worth, and might also 
deteriorate the market value of the wheat or 
even impart to it deleterious properties. 
dies or preventives directed against the matured 
larve or the pupe have been suggested by some 
distinguished savans on the assumption that 
they burrow in the ground, and by others on 
the assumption that they principally or wholly 
continue attached to the harvested corn. “It 
is possible,’ says Mr. Duncan, “that Mr. Gor- 
rie’s plan of ploughing the wheat stubbles, and 
having what is called a skim-coulter attached, of 
such a construction as would cut and lay about 
an inch of the surface at the bottom of the fur- 
row, would bury many of the pupz at such a 
depth as to render their resurrection improba- 
ble. But grass and clover seeds are so often 
sown with wheat, that this method can seldom 
be practised, even if there was more inducement 
to follow it than there really is, without deviat- 
ing from the ordinary rotation. The same ob- 
jection will apply to Mr. Poppy’s suggestion of 
burning the wheat stubble on the land; but 
when this can be done, it promises to be a highly 
useful expedient. When the stubble is short 
and scanty, the conflagration may be assisted by 
straw, or other inflammable matters, (such as 
dry furze,) brought for the purpose. If it is 
rank, as is usually the case in Suffolk and some 
Reme-. 
WHEAT-FLY. 
other southern counties where the reapers scarce- 
ly bend their backs in cutting the crop, the fire 
will be sufficient to heat the whole surface of the 
ground, and in all probability will destroy the 
greater part if not the whole of the pupe, heat 
being speedily fatal to them.” But the probabi- 
lity is that a large proportion of the larve which 
live to become pupe remain attached to the har- 
vested corn till separated from it by the process 
of thrashing, and that they are afterwards con- . 
veyed, in mixture with the chaff-dust, either 
directly or indirectly to the ground, and there 
pass in spring or in early summer into their pupa 
state ;sothat a method of prevention recommend- 
ed by Professor Henslow, for separating the chaft- 
dust and afterwards carefully collecting and burn- 
ing it, may be by far the most efficient of all the 
methods hitherto proposed, and certainly is the 
cheapest and easiest. He says, “It occurred to 
me that, if a wire-gauze sieve were placed before 
the winnowing-machine in a sloping position, so 
as to allow the chaff to fall upon it and then roll 
from it, the pupe would pass through, and might 
be caught with the dust in a tray placed below 
the sieve. I have put this to the test of experi- 
ment, and find it answer perfectly. Two pieces 
of wire-gauze were placed together at an‘angle, 
sloping like the roof of a house, and the chaff 
readily fell off on each side to the floor, while 
dust and pupe passed through. Ifa simple con- 
trivance of this kind formed an appendage to 
every winnowing-machine in the country, what 
myriads on myriads of the pupe might be col- 
lected and destroyed!” 
Some natural enemies of the wheat- midge, 
however, keep it powerfully in check; and, in 
particular, three species of ichneumons, “ minute 
benefactors of our race, sent in mercy by Heaven, 
know how to introduce their eggs into its larva, 
thus preventing the mischief they would other- 
wise occasion, and saving mankind from the 
horrors of famine.” One of these ichneumons, 
Encyrtus inserens, is black and shining, and about 
half the length of the wheat-midge; another, 
Hurytoma penetrans, is black, with a brassy lus- 
tre, the abdomen glossed with blue, compressed, 
and truncated behind; and the third and most 
important, Platygaster tipule, is a minute black 
midge-like fly, with the legs and the base of the 
antennz red,—the male quite black, and rarely 
seen,—the female of a pitchy colour, with a 
sharp ovipositorial point at her tail, exceedingly 
abundant and active in all infested fields in the 
months of July and August. “Superficial ob- 
servers who have noticed the larve of the wheat- 
midge in the ears,” remarks Mr. Sidney with 
particular reference to the Platygaster tipule, 
“have mistaken the ichneumon, which they 
have observed amongst them, for the parent of 
these larvee, and have consequently condemned 
it as the origin of the very ills it is destined 
to diminish. This affords another instance of 
the folly of hasty conclusions, and of the false 
