THE MONTHLY BULLETIN. 163 



DECIDUOUS FRUIT INSECTS. 



The Peach Twig'-borer. 



In a recent issue of the Bulletin a brief description'of the work and 

 appearance of the twig-borer was given, and need not be duplicated here, 

 except to say that the small black-headed larvaj destroy the young buds 

 ;ind shoots in the spring and summer. The lime-sulphur solution, the 

 best spray that we know for this insect, must be applied when the 

 blossoms begin to open. The commercial preparation diluted one part 

 to ten of Avater and applied under a pressure of about 200 pounds, has 

 given excellent results. 



The Peach Borer. 



This pest is fortunately rather limited in its distribution, where it is 

 found in the Santa Clara Valley, Alameda and San Mateo counties; 

 slight infestatiims are also reported from the more southern counties, 

 Ventura and Riverside. It attacks primarily the peaCh, apricot, plum, 

 prune and cherry. The eggs of this moth are laid on the lower trunks 

 of the trees a few inches above the surface of the soil and the newly 

 hatched larvte bore through the bark. The burrows are generally made 

 under the surface of the ground and through exit holes; the exuding 

 gum, indicating the presence of the borer, is forced. The larvae remain 

 in their burrows during the winter months, passing there the resting 

 stage in the early spring. The adults emerge sometime later. Control 

 measures consist in the use of the resistant JMyrobolau cherry-plum as 

 a stock upon which trees are budded or grafted ; protective washes of 

 lome-crude oil mixture, lime-sulphur-.salt mixture, digging out the worms 

 or killing them with a crooked wire. The use of hard asphaltum, grade 

 "C" and "D" applied to the tree trunks, preventing the issuance and 

 entrance of a vast majority of the insects has been advocated by Earl 

 IMorris, Commissioner of Santa Clara County. The warm asphaltum 

 is applied from five to six inches below, and above the surface of the 

 soil with a brush; two coatings are put on. 



The Pear Thrips. 



The description and work of this pest appears in a previous issue. 

 The pear, prune, plum, peach, apricot and almond growers should be on 

 the lookout for these minute active insects and at the time they appear 

 in numbers a thorough high pressure spraying should be applied, hold- 

 ing the nozzle close to the buds and directing the spray into them. The 

 Government formula for this spray consists of three per cent distillate 

 emulsion combined with Black-leaf 40, 1 to 2000 parts of water. 



The Codling Moth. 



Because of the importance of the codling moth as an apple and pear 

 pest, we beg to call attention again to this insect. It is generally knoAvn 

 that wormy apples are the result of the attack by the larvae of this moth 

 and that clean apples are the result of spraying with arsenate of lead. 

 Two applications are necessary on pears and three, as a rule, on apples. 

 The strength of poison to use is 5 pounds to 100 gallons of water. The 

 first spray must be made when the petals are falling and before the 

 calyx cups close. A high pressure in spraying must be maintained and 

 all parts of the tree covered. 



