CALIFORNIA FRUITS: HOW TO GROW THEM 



The most notable of these because of its evil work in the central 

 part of the State, and because the grub destroys the roots of the vine 

 causing it to be called the "grape root worm, and the beetle riddles 

 the leaves and young fruit. It is Adoxus vitis and a special study of 

 it has been made by Professor H. J. Quayle of the University Ex- 

 periment Station, the results of which are published in Bulletin 195 

 of the station. The beetle is about one-fifth of an inch in length and 

 is black or brown. It can be killed by spraying or dusting the fol- 

 iage with lead arsenate. 



INSECTS UPON BARK OR SURFACE OF LEAVES 

 OF FRUIT 



Leaf Lice. Leaves of fruit trees, especially the apple and plum, 

 are sometimes almost covered with lice or aphides of different colors, 

 from light green to black, some individuals having wings and some 

 wingless. Available remedies for all these leaf lice are the kerosene 

 emulsions and other mixtures which will be given later as summer 

 washes for scale insects, with a spray nozzle which sends spray 

 upwards, so as to reach the under sides of the leaves. Very often 

 these pests are apparently cleared out by lady-birds and other insects 

 which devour them. 



Thrips. Very minute insects infesting buds, leaves and blos- 

 soms of pears, prunes, cherries, peaches and many other trees and 

 plants. The attack on leaves and buds causes them to wither and fall 

 off. Indeed complete defoliation may follow their attack. When 

 thrips infest fruit blossoms the essential parts are eaten off by the 

 insects and the attacked blossom sets no fruit. Much damage is done 

 by the insect and thorough investigation has been pursued by several 

 investigators of the Bureau of Entomology of the U. S. Department 

 of Agriculture, and by the California Experiment Station. Early 

 results indicate that the insect is capable of control by spring spraying 

 with several insecticides, preparation and application of which is 

 given in detail in California Experiment Station Circular 223 (No- 

 vember, 1920), and should be carefully studied. 



The first application should properly be made when the thrips are 

 coming from the ground in maximum numbers and before the cluster 

 buds are too far advanced. This period in the San Jose district is 

 early in March, but it of course differs for the several varieties of 

 fruits. An effort should be made to kill all adults in an orchard be- 

 fore March 15, when practically all thrips are out of the ground and 

 when egg-laying on the stems of leaves or bloom begins. 



Spraying can be done with safety to opening buds, but should not 

 be sprayed on trees in full bloom, and its use can be resumed imme- 

 diately after the blossoms have fallen, and later on the foliage for 

 adults and larvae. 



The necessity for spraying will depend upon the number in a 

 blossom. As the blossoms are barely opening the thrips should be 

 shaken out of a few blossoms on white paper. If only two or three 



