affecting the Turnip-Crops. 
131 
With this exception I know of no parasitic insects to keep these 
turnij)-destrojin<T^ maggots in check : I shall therefore now con- 
clude this investigation of their habits and economy by append- 
ing such remedies as have fallen in my way. It often happens 
that very good specifics which may be successfully employed in 
the garden cannot conveniently be extended to the field : such, I 
fear, is the following remedy proposed by Bouche. He says that 
where whole fields of cabbages have fallen a sacrifice to the 
destructive maggots, that the crops are now completely preserved 
by dipping the roots, as they are transplanted, into oil or ley of 
ashes. One of the best modes of diminishing their numbers, 
I doubt not, is to pull up and remove infected plants on the first 
symjitoms of the presence of insects at their roots, which is in- 
staiuly detected by the drooping of the leaves in the sunshine, 
those of the cabbages turning of a faint lead colour, and the tur- 
nip-tops becoming yellow. When this is the case, they should be 
immediately carried away and burnt, and brine or ley of ashes 
may be at once poured into the holes from whence the plants 
have been drawn, to destroy any insects left behind. In other 
instances, where the maggots have made great havoc with the 
cabbages, cauliflowers, and brocoli, gardeners have collected large 
quantities of the brown pupa? from the roots with the hope of 
checking their increase ; and as the transformations of the in- 
sects are in rapid succession, it must have a good effect by giving 
the succeeding crops a better chance of escaping the fate of those 
which preceded them. 
r. Sinclair, in allusion to the turnip-galls, says, " Combina- 
tions of salt and lime were evidently the most effectual, as no 
instance occurred of the bull) being affected below the surface of 
the soil. That portion, however, of it which was above the sur- 
face was affected with galls, the same as in the bulbs grown on 
soils of the same nature, to which no application of manure had 
been applied. On a space of the same soil, to which salt simply 
had been applied the preceding spring, and from which time the 
soil remained fallow, the crop was good. One plant in ten, how- 
ever, was affected with the disease below the surface, as well as 
above it. The salt in this instance had been applied at the rate 
of 8G bushels per acre, and mixed with the surface 4 inches deep : 
it was applied the first week of May, 1818. On one portion of it 
barley and turnips were sown, but they did not vegetate, the dose 
being too great. The season following, however, the crop was 
good." It was observed that the same dressing on a clayey loam 
did not prevent the galls from forming. I apprehend, however, 
that the lime and salt would certainly destroy the different mag- 
gots that we have described, but not the weevils : for it must be 
remembered that the author of the galls is a hard beetle, and its 
ii2 
