18 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. 



open or gouged out on one side (Figs. 12, 13), and the growth inter- 

 fered with as a result of an attack of these beetles in May or June. 

 The beetles may continue to feed for a month or more. After feeding 

 a couple of weeks egg laying begins, and this takes place at intervals 

 of a week or two, when the clusters of eggs are deposited as already 

 indicated. 



The beetles are very easily jarred from the vine upon the slightest 

 disturbance, and fall to the ground "playing 'possum" and remain 

 quiet for a short time, but soon become active again when left undis- 

 turbed. This habit of readily dropping to the ground offers a means 

 of controlling the insect in this stage. The beetles fly around but 

 little, and will usually be found in the immediate vicinity in which 

 they emerged. The vineyards which were under observation showed 

 that the great bulk of the beetles were confined to a comparatively small 

 area, and reports from the owners indicated that they had been present 

 in these spots for several years. 



In the case of some vineyards, according to statements made by the 

 owners, these beetles have been present for a good many years. In 

 such cases as these there seems to have been some factor in keeping 

 them from becoming excessive and destroying the vines. In one vine- 

 yard near Lodi, where the beetles are said to have been present for 

 many years, they have become especially abundant only during the 

 last year or two. During this period they have also spread more 

 rapidly, and since it has become known that they feed upon the roots 

 as well as the leaves the growers have begun to realize their importance, 

 and remedial measures will be undertaken against the insects. 



CONTROL MEASURES. 



Natural. Probably the most important factor in the way of climatic 

 control of this insect would be unusual rainfall during the winter 

 season. During the winter of 1907, which was a very exceptional 

 one, large areas were covered with water which hitherto were unknown 

 to have been flooded. Where this exceptional amount of moisture pre- 

 vailed and vineyards were covered for a couple of weeks, there were 

 very few beetles during the following season. Except in one or two 

 cases, however, we were not aware of the fact that beetles had occurred 

 in those situations in previous years. But they were, nevertheless, 

 present again in 1908. 



Aside from excessive moisture in the soil, there is little in the way 

 of climatic control that will aid in the fight against the insect, unless it 

 would be in some condition that would be conducive to the development 

 of a fungus affecting the adult beetle. In our interior California 

 weather, however, of May and June there is little hope of anything 



