VINEYARD SPRAYING AGAINST ROSE-CHAFER. 59 
made to control the rose-chafer by the same means and more or less 
experimentation along this line has taken place. 
_Cage experiments with arsenical poisons against the beetles seemed 
to indicate that a large amount of arsenic was necessary to kill them. 
At a date previous to the general use of arsenate of lead heavy appli- 
cations of arsenicals in some instances resulted in serious injury to 
the foliage of grapevines. This injury was caused by heavy appli- 
cations of London purple, Paris green, and arsenite of lime, which 
are some of the more caustic forms of arsenicals. With the placing 
upon the market of reliable and properly-made brands of arsenate of 
lead, however, an arsenical is now available which can be used in 
large amounts without injury to the foliage of the vine. Hence there 
is now practically no danger of injury by arsenical burning, and in 
addition to this the arsenate of lead has a much greater adhesive 
quality than the other arsenicals previously mentioned, thus render- 
ing its poisoning effect of longer duration. 
In the field experiments against this pest during the past season, 
arsenate of lead was used in combination with Bordeaux mixture and 
in most instances at a strength of 5 pounds of arsenate of lead to 50 
gallons of the spray liquid. 
Experiments were undertaken in three vineyards covering 4 acres 
of grapevines on the farm of Page Bros., at North East, Pa., 4 acres 
on a vineyard owned by fhe Prospect Park Fruit Farms Co., and 3 
acres on the farm of Mr. C. F. Hirt. Since this pest breeds outside 
the vineyards it is well-nigh impossible to predict, beforehand, either 
the extent of the infestation or the portions of the vineyard most 
likely to be infested, although the latter condition may be deter- 
mined to some extent by close observations of local conditions over 
several seasons, and since it is desirable that the first feeding of 
the invading beetles shall be upon poisoned blossom-buds and foliage 
this necessitates the application of the first spray on or about the time 
the first beetles appear. Thus at the time of selecting a vineyard for 
experimental work the extent of infestation likely to occur during the 
season is quite problematical. The only thing to be done is to select 
vineyards reputed to suffer annually from invasions by this pest. In 
two of the experiments, those in the vineyard of Page Bros. and of 
Mr. C. F. Hirt, the first application was made before the grape 
blossom-buds had opened and before the beetles appeared. 
The plat arrangement in the Page vineyard was as follows: 
| | 
Rows. Bordeaux mixture. | eae Molasses. | Water. 
| Pounds. | 
Bauer MNOUMOSF Reams 4 cc cise /56s ae seh oc ae bain! baleiieglionessucs. soc 50 gallons. 
12 | Lime, 3 pounds; copper sulphate, 3 pounds... .---. 5 | 1 gallon= = -<-2-= - 50 gallons. 
GU SCE. Tos ec 2 Se es ee De Se Eee ee ee ee 
16 | Lime, 3 pounds; copper sulphate, 3 pounds... ----- HI NONGseaseee aes -| 50 gallons. 
