94 Second Report on Economic Zoology . 
in contact with them, no harm is done. On the rest of the land I 
should give a dressing of nitrate of soda at the rate of 2J cwt. to 
the acre. 
“ I am not quite certain as to the species attacking your land, until 
I hatch out some of the flies, but in two of our commonest kinds it 
is noticed that the grubs come on to the surface at night, especially 
on warm damp nights.' When this takes place much benefit to grass 
land has been derived by rolling of a night. Of course this means 
extra expense, but it has often amply repaid the extra cost of labour 
in attacks on grass land. Certainly try rolling and bush-harrowing 
when the flies appear and use nitrate of soda. 
“ Although rape meal (or dust) keeps the grubs away from the 
roots, it nevertheless does harm in the end, for it, undoubtedly, 
attracts the insects wherever it is placed. 
“ Bisulphide of carbon is highly inflammable and the fumes are 
poisonous to man, so must be used with care.” 
Corrosive sublimate was experimented with and where the land 
was thoroughly soaked with a solution of 1 oz. in 6 gallons of water, 
many, but not all, of the leather-jackets were killed. As these larvae 
feed on roots, not earth, we must not expect the same benefit to be 
derived from its use as in earthworms. 
The worm -killer referred to by Professor Hall is made as 
follows : — 
Mercury perchloride . . . .10 lbs. 
Hydrochloric Acid . . . .4 lbs. 
Water . . . . . .6 lbs. 
To dilute for use, use \ oz. fluid to three gallons of water 
(= 1 in 1000). For worms on lawns it is an excellent remedy. 
The secretary of the club wrote again in May and in this com- 
munication stated as follows : — 
“ We had thought of trying a small piece of ground with lime and 
gas water. The ground where the damage was done is undulating 
and we find that the higher parts have still some grass left whilst 
the lower parts are bare.” 
Lime, unless put on hot, would not do much good. 
These pests are always worse in damp low-lying parts of fields, etc. 
In some cases, damp areas which are, or rather were, always infested 
have been freed from these pests by drainage alone. The flies seek 
moist soil in preference, so fly to low-lying patches where the 
moisture collects. 
