Quarterly Report of the Hon. Consulting ^Entomologist. 367 
pushing on the crop. The following observation, however, given by 
Mr. James Fletcher, Consulting Entomologist of the Dominion 
of Canada, in his ofi&cial return in the Government Reports of 
the Experimental Farms of Canada, page 167, is well worth con- 
sideration : “ but the most satisfactory remedy was a kerosene 
emulsion.” This so-called emulsion is a mixture of boiling soap- 
suds, or soft-soap suds, with kerosene, churned or violently stirred 
until the ingredients unite •, but as I have scarcely met with anyone 
in this country who could do this properly, though it is one of the 
commonest American remedies, I would suggest purchase of a very 
similar soft-soap mixture, which may be bought in solid form ready 
for diluting. This was specially prepared for some bad insect 
attack in Mauritius, on the property of one of my correspondents, 
by Messrs. Morris and Little, of Doncaster, and is sold under the 
name of Anti-pest, and I believe it to be a very good application. 
Mr. Fletcher also states that when the caterpillars appear early 
in the season before the cabbage head begins to form, Paris green 
and flour, one part of the former to fifty of the latter, may be 
dusted on the plants, but that the kerosene emulsion would pro- 
bably be the best remedy, as the fluid would drop on those which fell 
to the ground, even if they were not touched by the spray on the 
leaves. Paris green, if used in powder, may be weakened down to 
a safe rate of application by plaster of Paris, in proportion of 50 lb. 
of the plaster to 1 lb. of the green (the same proportion as is men- 
tioned for flour), or gypsum may be used. A safe and simple 
method of application on a small scale is to put the powder in a 
box, with one end covered with wire gauze, or finely perforated. 
The box being fixed at the end of a stout stick, about three feet 
long, is a convenient implement for distribution. The bearer, by 
striking the handle with another stick, causes the powder to fall 
evenly, and if he is careful to walk to windward of his work there 
is little danger of his inhaling the powder. But looking at the 
poisonous nature of the application, it appears to me that where it 
is sent broadcast into the air by machine power, there is great 
danger of its being inhaled both by men and horses, and though the 
method may be safe, I should not myself like to recommend it. 
Sucli different proportions are given for different kinds of 
leafage that it is impossible to say how much powder would be 
needed for an acre, but for dressing potatoes 3 lb. of green to about 
36 lb. of flour is one amount given, so that the above recipe of 50 lb. 
of flour to 1 lb. of green (the strength advised for Diamond-back 
caterpillars early in the season) would presumably dress a good deal 
more than one acre of infested seedlings. 
The method of use and proportion of Paris green in solution, 
and also names and descriptions of various kinds of spraying 
machines, are already before the public ; but I shall have pleasure 
in giving every information in my power. 
It maybe some assistance in identifying the Diamond-back moth, 
to remind readers that this little grey moth takes its name from 
having a row of spots or saw-like markings down the hinder edge of 
B B 2 
