84 SOME INSECTS INJURIOUS TO TRUCK CROPS. 
the hop flea-beetle. Being more adhesive, this mixture, when sprayed 
upon the plants, sticks more firmly to the leafage than Paris green, 
and is also very much less likely to produce scorching or burning; 
indeed, it has been used at T pound to 10 gallons of water on some of 
the hardier plants, such as potato, without injurious effects. This is, 
however, not advisable, owing to the extra cost, provided that a 
weaker solution will accomplish the object. Moreover, scorching is 
apt to follow its use at this rate on some plants, especially when these 
are exposed to the direct rays of the sun. The adhesiveness is still 
further enhanced by the addition of about the same amount by 
weight of resin-fishoil soap as of the arsenical employed. Mr. Wil- 
son reported that arsenate of lead, applied at the rate of 4 pounds to 
40 pounds of Bordeaux mixture, was inadequate, yet Mr. Quayle re- 
ports that used at the rate of 5 pounds to 50 gallons it will kill a 
large number of the beetles, although many take to the new growth 
that is constantly appearing, or apparently carefully avoid those 
places on the foliage that have a good coating of poison. The failure 
of these two arsenicals must be attributed, in large part, to unsuitable 
spraying apparatus; either of these applications should kill insects 
on hops, as they have both been found effective, according to Fletcher, 
against this same beetle on rhubarb in the Northwest Territory and 
Manitoba. 
Dry Paris green. — Mr. Thos. Cunningham reported that very 
little impression was made by an arsenical spray in the region just 
mentioned, but stated that Paris green dusted on the plants seemed to 
produce better results. It was applied by means of a Leggett powder 
gun. Even then some trouble was experienced; in fact, as the 
arsenical dust or so-called " dust spray " struck the vines the " fleas " 
hopped to the ground. " In all my experience with insecticides," he 
says, " I have never seen anything which will approach the fleas in 
resistant power." 
Paris green spray. — Paris green, being the most readily obtainable 
insecticide, was advised by this Bureau when information as to 
remedies was requested. When properly prepared and applied, 
according to the directions furnished in Farmers' Bulletin No. 127, 
this insecticide should have no deleterious effect on the hop or other 
plants affected. It was advised that other food plants growing in the 
vicinity, such as rhubarb, turnips, and weeds, should be sprayed with 
the solution. 
Regarding its efficiency in hop fields Mr. John Wilson, in a report 
to the late Doctor Fletcher, stated that when applied at the rate 
of from 4 to 8 ounces, in combination with Bordeaux mixture, made 
according to the 1 1 4 formula, or in 40 gallons of water, it was not 
successful. 
