Tlie recent appearance of the Hessian Fly. 
725 
Canada, to whom I submitted specimens of injured straw and 
of the " flax seed " pupae ; and with regard to the developed fly, 
by the equally skilled opinion of Mr. R. H. Meade, of Man- 
ningham, Bradford, well known for his investigations regarding 
the determination of species of diptera, to whom I submitted 
the specimen. 
The details by which this attack is to be kept in check must 
differ according to circumstances, — but the principles are 
these : — 
Destroy the flax-seed pupae, if this can be done by cutting the 
crop high, and burning the infested stubble. If this cannot be 
done, destroy the pupae, where and how this can be managed, by 
taking care that the straw is so treated that the flax-seeds 
cannot develop in the manure ; and if for certain prevention, 
the chaff also should be similarly treated ; for though if used as 
food the pupae in it may thus be destroyed, yet it is possible that 
they may have developed to flies, and be spreading evil on all 
sides, before the chaff is consumed. The plan of what is called 
in America, " bait," is extremely likely to be of service ; this 
is, where bare barley-stubbles are not collected and burnt, to 
leave them untouched for about six weeks from harvest ; thus 
all of the Hessian flies which have developed, will, in all proba- 
bility have laid their eggs on the young plants sprouted from 
self-sown corn ; and, by turning sheep on, the eggs will be de- 
stroyed by means of the sheep eating the leaves, and such 
maggots as have established themselves at the centres of the 
plants, will (if they escape being cleared by the sheep) be 
destroyed by means of the plants that feed on them being rooted 
up and killed by careful cultivation following the sheep. Sheep 
having fed in autumn or spring, either wheat or barley which 
had been attacked, the land would be improved by nitrate of 
soda, or some other stimulating dressing following. 
Dressings of lime, or of soot and lime, or anything else 
obnoxious to the maggot, are eminently desirable where attack 
shows, as may very frequently be the case on young barley- 
plants in clover-stubbles. Such materials, properly applied, 
run down in solution to where the maggot is sheltered, and 
while they are bad for it, they are very beneficial to the 
clover. 
All applications, measures of cultivation, &c., suitable to 
secure a healthy and hearty growth are of service, as thus (in 
case of the attack from flies now developing), the young plant 
will push on good shoots after the time for egg-laying has 
passed, and, — in the case of the attack of the April and May 
brood, which deposits at the first or second joint of the growing 
