18 BULLETIN 902, U. S. DEPARTMENT OP AGRICULTURE. 
BORDEAUX MIXTURE. 
It lias been known for many years that Bordeaux mixture is an 
almost perfect deterrent against flea-beetles. There is something 
extremely distasteful in it to this class of pests but unfortunately 
it has not been tested thoroughly either alone or in combination 
with arsenicals. It is recommended that tests be made both alone 
and in combination with arsenate of lead, arsenite of zinc, and 
calcium arsenate against this species. The standard Bordeaux 
formula 4-4-50 should be employed. 
NICOTINE SULPHATE. 
Experiments were made with nicotine sulphate at the rate of 3 
oimces with whale-oil soap, 8 ounces, in 8 gallons of water, with the 
result that the beetles were stupefied although not killed. In these 
instances there is abundant proof that the flea-beetles were strongly 
repelled but further experiment is desirable to determine how often 
this preparation should be used, that is, at what intervals. Xaturally 
since tobacco dust has been found successful, nicotine sulphate 
should be nearly as useful if not equally so. 
INEFFECTIVE DETERRENTS. * 
In some regions where the western cabbage flea-beetle is destruc- 
tive, growers dust the infested plants with air-slaked lime, ashes, 
insect powders, soot, or Paris green, but experiments made in Colo- 
rado have demonstrated that beneficial results from these substances, 
which also act as repellents, are of short duration in that State. 
The dry, high winds which prevail there render it difficult to apply 
an even coating of any form of dust or powder or to make such 
material adhere to the lower surface of the leaves where it is usually 
most needed. 
A better coating, however, may be applied to the rough-leaved 
foliage of turnip, radish, and mustard than to the smooth-leaved 
cabbage, and some growers claim that the former class of crops may 
be efficiently protected by dusting with lime. 
TOBACCO DUST. 
A liberal application of finely ground tobacco dusted on the 
infested plants at 3 or 4 day intervals can be depended upon to protect 
radish, turnip, mustard, and similar vegetables from the beetles and 
for use on small areas is one of the most satisfactory control measures 
that can be recommended. 
The accompanying illustration (PI. I, fig. 2) shows a method of 
dusting with an arsenical or deterrent by means of a traction sprayer. 
MAINTENANCE OF THRHTY GROWTH. 
In regions where the western cabbage flea-beetle is a dangerous 
pest the farmer is advised to keep the plants in vigorous condition 
