CONTROL OF THE GRAPE-BERRY MOTH. 35 
applied at this time is especially apt to collect at these places again, 
at which point it may be most effective later. It also covers the 
berry, and since there is comparatively little growth following this, 
it remains over the larger part of the surface until it is weathered off, 
or for about two months. Thus it remains effective during the period 
when the greater part of the second-brood larvae hatch. As shown 
by the single-spray applications in 1916, this second spraying is prac- 
tically as effective against the second-brood larvae as is one applied 
three weeks later, just as they are beginning to hatch. 
Larvae which succeed in entering the first berry may be poisoned 
upon moving to a second. Larger larvae seldom consume enough 
poison to prevent their entering the grape berry, but may be found 
dead in the berry a day or two later, whereas those that have reached 
the fourth stage are seldom susceptible to poison in the amounts in 
which it is to be found, after weathering, on sprayed grapes. 
If this schedule is followed closely, the places on the grape berry 
at which the majority of the larvae would normally enter should be 
well covered with poison, and the surface of the berry as a whole will 
be covered for a longer time than by two sprayings applied at any 
other time. If the first application were made earlier, before the 
falling of the grape blossoms, most of the poison would be lost with 
the shedding of the floral parts, and the application would be com- 
paratively ineffective. If the second application were made earlier, 
while the berries were still growing rapidly, it could not cover the 
surface of the berries permanently nor could it collect at the points 
where the berries would touch, and while it might destroy more of 
the first brood, it would be almost entirely ineffective against the 
second. Hence no variation in the time of these two applications is 
advisable. 
Relation of Different Grapevtne Training Systems to Spraying. 
The system of pruning and training a vineyard must be largely 
determined by horticultural considerations. Nevertheless the dif- 
ferent systems greatly affect the facility with which the grapes may 
be sprayed and in other ways are related directly to the control of 
insect pests. To determine the relation to grape-berry moth con- 
trol of five of the more important systems, a small block in Mr. A. P. 
Bartlett's vineyard was used in 1916. In all of the other spraying 
experiments the vines had been trained according to the Chautauqua 
system. This block was trained by the owner especially for this 
experiment according to the Four-cane Kniffin, Munson, LTmbrella, 
High-renewal, and Chautauqua systems. 
As there may be many who are not f amiliar with all of these vine- 
training systems the following brief descriptions have been compiled 
from the papers of Husmann (15) and Gladwin (14). 
