REPORT OP COMMITTEE ON PUBLICATION 179 



be checked to a considerable extent by spraying very heavily with a strong 

 poison spray, thus killing thenr where the vines are already infested. 



GRASSHOPPERS. 



The most serious injury done by grasshoppers is where outbreaks of 

 these insects occur, coming in from surrounding uncultivated lands. Vine- 

 yards most likely to be subject to this attack, occur in new sections where 

 there is considerable pasture land in the vicinity. The eggs of the grass- 

 hopper are laid in the ground in the late summer or fall in uncultivated land. 

 These eggs remain in the ground during the winter and hatch in the follow- 

 ing spring. 



Grasshoppers may be controlled by a poisoned bait, by spraying heavily 

 a few rows along the border of the field, by the hopperdozer, by burning 

 waste areas, and by the introduction of turkeys into the vineyard. A com- 

 bination of two or more of these measures may be used to fit particular cases. 

 Of the methods used to directly protect vineyards, poisoned bait is probably 

 the most common. 



GRAPE LEAF FOLDER. 



Desmia funeralis HUb. 



This insect occurs in scattering numbers over a wide section of Cali- 

 fornia, but important injury is done only in restricted localities and during 

 occasional years. The insects may be detected in a vineyard by the char- 

 acteristic rolling of the leaves. One edge is rolled up rather tightly to about 

 one-half way across the leaf, making a tube less than the diameter of a lead 

 pencil in which the larva lives. The leaf is always rolled on the under side. 

 The larvae feed by eating off the free edge of the leaf in the interior of 

 the roll, so that they are always protected by the outer layers of the rolled 

 portion. The insect hibernates as a chrysalis, appearing and laying eggs 

 upon the vine in the spring. There are apparently two generations of the 

 insect during the year in California. This same insect is a more or less 

 important pest of the vine in the Eastern States, but there its habits are strik- 

 ingly different from that of California. In the East the leaf is simply folded 

 over on the upper surface and the edge is sewed down by strands of silk, 

 while in California the leaf is very distinctly rolled. As a general rule the leaf 

 folder does not occur in numbers sufficient to warrant treatment, and the 

 only treatment applicable would be the application of an arsenical spray just 

 after the eggs are hatching and before the rolling of the leaves occurs. 

 Once the leaf is rolled the insect is completely protected from the spray 

 and the only way to rid the vine of them in that stage is to pick them off 

 or crush them within the roll. 



HAWK MOTH LARVAE. 



These larvae, while occurring in occasional numbers, are of little con- 

 sequence as a pest except once in a great while when outbreaks of them 

 occur and they do serious injury to small areas of vines. These larvae are 

 very large worms similar to those which attack tomatoes and tobacco. The 

 insect hibernates in the pupal or chrysalis state and while in the ground, 

 may be distinguished as a large cylindrical object of a dark brown color. 

 a.bout the middle of May they emerge from the ground and deposit their 



