6 FARMERS’ BULLETIN 121. 
numbers. Every year or two “ new and successful remedies” are sug- 
gested, but when tested on a large scale in badly infested vineyards 
or orchards, these are found unsatisfactory. 
The greatest difficulty encountered is that any application that 
may be made is unsuccessful unless applied almost continuously. 
Poisons that will kill the beetle are not satisfactory when the insects 
are abundant, because of their comparatively slow action. The blos- 
soms have already been entirely destroyed before the poisons have 
taken effect, and the dead beetles are constantly being replaced by 
others that come from the ground or fly from neighboring places. 
Every beetle on a plant may be destroyed one day, but on the day 
following the plant will again be completely covered by them. More- 
over, it is difficult to spray an entire garden so that every bud and 
blossom will be coated with the poison. 
PRACTICALLY USELESS APPLICATIONS. 
The various compounds of copper, lime, kerosene, and pyrethrum, 
hot water, and other so-called sure remedies have failed to give the 
desired results when subjected to a rigid test. Some substances, 
pyrethrum, for example, will stupefy the beetles for a short time, 
but they soon recover and resume feeding. 
Hot water is not effective because of the practical impossibility of 
applying it in a spray or jet at a sufficiently high temperature to kill 
the insects and not destroy the fruit and flowers. 
Decoctions of tobacco and quassia, as well as solutions of helle- 
bore, alum, and a number of proprietary remedies that have been 
tried, apparently have no deadly effect on the rose-chafer. 
USE OF ARSENICALS ON ROSES. 
Paris green has not proved a success against this species, for, while 
it will not discolor the leaves badly, it will damage the flowers. 
Furthermore, repeated applications are necessary. When Paris green 
is added to Bordeaux mixture the combination produces bluish dis- 
colorations and seems to have little, if any, effect as a repellent. 
Arsenate of lead has been tried and found to be more destructive 
than other arsenicals, acting both as a repellent and a poison, but 
it works more slowly. It also has the disadvantage, in the case of 
ornamentals, of leaving a whitish deposit. Arsenite of zinc leaves 
a still thicker and a more permanent white deposit, and if fish-oil 
or similar soap is used as the “sticker,’ or adhesive, this latter 
substance leaves an unpleasant odor. 
It is obvious, therefore, that we can not depend upon any of the 
arsenical group as preventives of injury by the rose-chafer to roses 
and other bright-flowering plants, although on some other plants 
they might be used successfully. Knowing these facts, it is not at 
all likely that the average rose grower could be induced to use any 
of the arsenicals. 
It is possible that a heavy application of arsenate of lead, say 5 
pounds to 50 gallons of either water or Bordeaux mixture, will 
largely protect ornamental plants that are hardy, and this plan 
should be tested by those who are confronted with this pest. Very 
thorough applications should be made on the first signs of the insects’ 
presence and repeated as found necessary. 
