REPORT OF COMMITTEE ON PUBLICATION 177 



by the spray, and which will deposit their full quota of eggs. For the Fresno 

 section of this State in average years, the time of spraying will be from 

 about May 20th to June 10th. The criterion to go by for each year and 

 locality is to begin spraying as soon as some of the nymphs are in the last 

 nymphal stage. 



THE CALIFORNIA GRAPE ROOT WORM. 

 Adoxus obscurus Fourcroy. 



This pest of the vine occurs in more or less restricted localities in the 

 San Joaquin and Sacramento valleys between Merced and Marysville. It 

 also occurs in the Sonoma Valley, but is not known as a pest on the grape 

 elsewhere in California. This insect injures both the roots and the growing 

 parts of the vine above ground. The most evident indication of infestation 

 of this beetle is in the narrow chain-like strips which are eaten out of the 

 leaves. The beetle also gouges out parts of the petioles, pedicels, berries and 

 shoots. The larva does injury under ground by eating off the small rootlets 

 or by gouging out strips of the bark of the larger roots. In cases of serious 

 injury by this larva, most of the little rootlets will be eaten off and a large 

 part of the bark of the larger roots. Vines thus affected show a stunted 

 condition, the canes fail to attain a normal growth, and in severe cases the 

 vine may be killed outright. 



The adult beetles appear in May and June, having emerged from the 

 ground where they have been since the previous year and where they have 

 passed through the larval and pupal stages. This beetle begins at once to 

 feed upon the parts of the vine above ground as already indicated. After 

 feeding for a couple of weeks, egg laying begins, the eggs being deposited on 

 the inner bark or in crevices, usually beneath two or three layers of the old 

 bark. They are laid in clusters of from four or five to twenty-five or thirty. 

 Upon hatching, the young larva crawls or drops to the ground and makes its 

 way to the roots where it begins at once to feed. It continues feeding 

 throughout the growing period of the vine, lies more or less dormant during 

 the winter, and comes to within eight or ten inches of the surface in the 

 spring for pupation, finally transforming to the adult and emerging from the 

 soil about the first of May of the following year. 



The adult beetle is very readily jarred from the vine and thus they may 

 be captured on a screen or tray provided for the purpose. This is particu- 

 larly applicable where the infestation is restricted to small areas in a vine- 

 yard. It requires, however, to be repeated several times because new beetles 

 keep emerging from the soil for a month or more. Where the infestation is 

 general over a vineyard, the most satisfactory treatment is to spray the 

 vines with a poison such as arsenate of lead. Here again the application 

 may be required to be repeated because of the new growth continually 

 appearing on the vine. 



CUT WORMS. 



Cut worms do more or less damage in certain sections every year, but 

 in occasional years they become very abundant and do serious injury. 1914 

 was one of the years in which they occurred in great numbers in a large 



