8 SOME INSECTS INJURIOUS TO TRUCK CROPS. 
develops in the spraying solution but is not freed in the dust applica- 
tion, and, again, the dust does not adhere to the leaves as well as 
does a liquid application. If arsenate of lead is the insecticide 
chosen, its adhesive qualities increase its value since it adheres much 
longer to the foliage in wet weather than has any other mixture yet 
tested, thus making frequent applications unnecessary. 
In the case of newly cleared land, which is frequently planted in 
potatoes as the first crop, it may be necessary to use a hand sprayer, 
or even a dusting bag, as the presence of tree stumps (PI. IT) seriously 
interferes with the effective use of power sprayers, but where possible it 
is desirable to make use of large machines for spraying, thus lessening 
the cost of application and increasing to a greater degree the efh- 
ciency of the remedial measures. The cost of a good power sprayer, 
properly equipped for effective work on potatoes, varies from $75 to 
$125, which amount would easily be saved in the space of one season 
by the increased yield in the potatoes treated, where a sufficient 
number of potatoes is grown to justify the employment of a power 
sprayer. As experiments have shown that treatment at least three 
times during the growth of the vines is well repaid by the increase in 
yield, a means of covering the planted areas rapidly and effectively 
is highly desirable, and the larger spray outfits are well adapted to 
this work. 
CONCLUSION. 
In conclusion, it is suggested that at least three thorough applica- 
tions of Paris green, or arsenate of lead, with Bordeaux mixture be 
made, the first applied about the time that the first eggs begin to 
hatch and the later applications at intervals of about three weeks. 
By this method the beetles should be easily controlled and the injury 
therefrom almost entirely obviated. 
