Annual Report for 1893 of the Zoologist. 
819 
bolic (the latter put in very strong), and it appears to have cleared 
off a very large number.” 
The moth is known to lay its eggs upon the sacks, and it is con- 
sidered that these are a frequent medium for the introduction of the 
pest into mills which have hitherto escaped infestation. 
Various methods of disinfection have been advocated. Baking 
the sacks or subjecting them to steam is not, I believe, practicable, as 
those in general use are of a nature to be greatly injured by such a 
process. M. Danysz subjects them to a sulphur fumigation in a 
closed box. 
Such measures are perhaps desirable, but, seeing that a very few 
eggs or larvre are sufficient to set up infestation in a mill, it seems 
almost hopeless to guard against the possibility of its introduction 
in some way or other, and attention should be chiefly directed 
towards such cleanliness and freedom from litter as shall make it 
difficult for the insect to gain a foothold. 
It is most important that in the building and installation of new 
mills this pest should be reckoned with, and the machinery designed 
with a view to its possible appearance. 
Root Flies. 
During June and July complaints were received of the ravages 
of root-fly maggots. 
These are the larvre of various species of the genus Anthomyia, 
the most common being : 
Anthomyia brassiem, Douche, the cabbage root-fly. 
Anthomyia radicum, Linn., injurious to cabbage and turnip 
roots. 
The species are so similar in appearance and mode of life that 
a separate description is unnecessary. The larvre are white or 
yellowish and legless, and when full-grqwn are not quite half an 
inch in length. They infest the roots of cabbages and turnips, and, 
when full fed, pupate in the surrounding earth, the sober-coloured 
grey fly emerging in about three weeks. Successive generations 
appear throughout the summer. 
Treatment . — It should be remembered that the attack is fostered 
by— 
1. The use of maggot-infested farm-yard manure. 
If the manure is suspected of containing the maggots, it should be 
rendered harmless by the admixture of gas-lime before use. 
2. The too frequent growth of similar crops. 
'Where cabbages are grown for many years in succession the pest is 
liable to become firmly established, and change of crop is imperative. 
Gas-lime, applied with the necessary caution, is the dressing 
which has proved most efficacious against root-maggots. Good results 
have been obtained by dipping roots, at the time of thinning, in some 
3 n 2 
