affecting the Corn-Crops. 
501 
the maggots of one attacking the corn when the ear is formed, 
but yet concealed iti the sheath, doing the greatest mischief in 
some instances, for not only are the ears not ripe at harvest-time, 
but they are either abortive or the grains are shrivelled and worth- 
less, and what is equally detrimental, the lateral shoots are rendered 
useless, owing to the advanced period of the season. The follow- 
ing, or second brood, deposits its eggs in the autumn-sown corn 
as late probably as the middle of October^ in open weather. It is 
true that from the attacks of this brood the central shoot perishes 
in the spring. This, however, only retards the growth a little; 
for the lateral shoots being strengthened, and having time to grow 
and produce ears, it appears that in some instances little or no bad 
consequences followed ; and it may be that even a more abundant 
crop has been produced under such circumstances. 
It is deserving of notice that white wheats are most palatable 
to these larva;, and I believe are generally preferred by noxious 
insects. When therefore it is stated that the Chlorops sometimes 
prefers rye and barley to wheat, it may be owing to its being red 
wheat, but at present this has not been substantiated. 
Of the two species belonging to the genus Oscinis, there seems 
to be no evidence of their producing two broods in a year. The 
lan'ae of the Swedish species (O. pumilionis) were small at the end 
of April, thev changed to pupa; at the end of May, and the flies 
were produced in the middle and end of June. Our British species 
( O. vastator) was found in the lurva state in May and June, to- 
wards Midsummer they changed to pupee, and the flies were 
hatching, during three weeks or upwards, in July. This is de- 
cidedly the most destructive species that has fallen in our way. 
With regard to the successive transformations of these insects, 
it is positively stated that the eggs are laid at the base of the 
leaves which sheath the ear, by the first or summer brood, and it 
may be presumed that the autumnal eggs are similarly deposited. 
To detect and destroy such atoms is impossible : the only remedy, 
at this period, would be to anticipate the female flies, and kill them. 
Whether it would be possible to attract the flies to any spot by 
white painted boards, or any liquor that would poison them, has 
not been ascertained. To drive the flies away by ammonia, gas- 
water, or other vapours, I should not think feasible ; but I doubt 
not that dusting the young corn-plants with soot or lime, on the 
first intimation of the fly in the autumn, would prevent the depo- 
sition of the egfgs. 
The maggots, or larvae, of the summer brood live between the 
stem and the sheath above ground : those of the autumnal brood 
appear to be close to, if not below, the surface. The former could 
not be affected by any application, I should imagine ; but strong 
liquid manures possibly might annoy the others. Hard frosts, 
2 L 2 
