378 THE MONTEILY BULLETIN. 



PloAving and sheeping, therefore, result in driving the hoppers else- 

 where for food or shelter during the winter season without actually 

 killing them, at least in any significant numbers. There is nothing to 

 assure the grower, moreover, that his vineyard may not be infested 

 again in the spring from the bordering roadsides and fences, or from 

 neighboring vineyards. For such measures to be appreciably effective 

 it would require a general community effort without considering 

 ■whether this would be the best general practice for the vines. It 

 appears to be a wise procedure to get as much material turned under m 

 the spring as possible. 



Spraying for the Young or Nymphs. 



The young hoppers may be very readily killed by means of a spray 

 applied to the under side of the leaves. The nymphs are readily killed 

 by a spray because they do not fly and hence cannot escape before the 

 spray. The spray also strikes their boclies and the breathing pores 

 directly, whereas with the adults the wings are held roof-like and very 

 completely protect their bodies from the spray material. 



The time to spray for the nymphs is just before the first of them 

 become winged, and this will be during May and the first part of June, 

 depending upon the season and locality. The kind of spray is not 

 important, for several different materials will kill the nymphs. Foliage 

 injury must, of course, be avoided. The material probably be.st answer- 

 mg these requirements are whale oil soap and tobacco. Whale oil soap 

 may be used at the rate of 15 pounds to 200 gallons of water. The most 

 desirable form of tobacco is the commercial black leaf, for it contains a 

 uniform nicotine content. Black leaf 40 may be used as follows : 



1 pint black leaf ; 

 4 pounds whale oil soap ; 

 200 gallons water. 



In the grape sections of the east the final recommendation of the 

 Bureau of Entomology at Washington for the control of this insect is to 

 spray for the nymphs with tobacco. In work carried on with this insect 

 in this State five years ago, spraying was recommended as a successful 

 means of controlling the nymphs ; but it was also stated that many 

 adults are present at the same time which would not be killed by the 

 spray, and that there were also eggs in the leaves that would not be 

 killed. The presence of eggs and adults, which are not affected, is the 

 mo.st serious objection to spraying, although there are enough nymphs 

 killed to materially reduce the numbers of the succeeding generation. 



The canes of the California vines are also pretty long by the first of 

 June, so that the problem of hitting every nymph on the under side of 

 every leaf is not an easy one. Moreover the breeding period seems to be 

 more prolonged here than in the east, where the seasons are definite, and 

 hence there are more eggs and full grown hoppers that are not killed. 



