1572 



ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 



small, and more tlian one borer may be 

 found in tbe same burrow. As fresb cast- 

 ings can nearly always be found at tbe 

 opening tbe larvae evidently clean house 

 every day. This mixed with the gum 

 nearly always indicates where burrows 

 can be found. When full fed the larvae 

 leave the main part of their burrows, seek 

 places where the adults can escape, form 

 cocoons out of silken threads and chewed 

 bark or pieces of soil, line them with silk 

 and pupate. The cocoons are elongate 

 oval in shape and about an inch in length. 

 Pupation usualy takes place about June 

 1, the pupal stage lasting about four 

 weeks. 



Eemedies and Preventhes 



At Cornell, where a four-year test of 

 eighteen or twenty preventives was tried, 

 the best preventives were: gas tar daubed 

 on the bark, waste tobacco stems and 

 leaves wrapped around the tree, tarred or 

 other paper wrapped about the trunk. 

 Relative value in the order named. At 

 Corvallis good results were obtained by 

 use of whitewash and Paris green and 

 thick Bordeaux and Paris green. 



There are two chief difficulties in the 

 digging out method. 1. At whatever peri- 

 od one does the work, there will be many 

 small larvae which will be undiscovered, 

 thus necessitating for the best results that 

 one go over the trees two or three times 

 during the season. 2. It necessarily does 

 more or less injury to the tree. Accord- 

 ing to Cornell results, however, this is the 

 only satisfactory method that can be used, 

 and should be supnlemented with one of 

 the preventive methods. 



The United States Bureau of Entomol- 

 ogy now recommends three formulas 

 which are being used in various parts of 

 the country against borers. They should 

 be applied just after worming. 



''Formula No. 1 — The lime-crude-oil 

 mixture; place about fifty pounds of rock 

 lime in a barrel and slake with ten or 

 fifteen gallons of warm water; while the 

 lime is boiling, slowly pour in six to eight 

 gallons of heavy crude oil and stir thor- 

 oughly. Add enough water to make the 

 whole a heavy paste. The wash should be 

 applied immediately with a heavy brush. 



"Formula No, 2 — The lime-sulphur-salt 

 mixture. Place about twenty-five pounds 

 of rock lime in a barrel and slake with 

 warm water. Add two quarts of sulphur 

 and two or three handfuls of salt while 

 the lime is still boiling. This wash is 

 heavy and is applied with a brush. 



"Formula No. 3 — Lime, coal tar and 

 whale-oil soap Unslaked lime fifty 

 pounds, coal tar one and one-half gal- 

 lons, whale-oil soap twelve pounds Slake 

 the lime in warm water and add the gas 

 tar while the mixture is boiling; dissolve 

 the soap separately in hot water and add 

 this to the lime solution. Add enough 

 water to make a heavy paste.'* 



Asplialtum Treatment for Peach Tree 

 Borer 



'^ In a recent bulletin of the California 

 station E. L. Morris calls attention to 

 the use of hard asphaltum, grades "C" 

 and "D," for the control of the peach 

 tree borer. This material was applied 

 early in the spring to badly infested trees 

 from which the borers had been dug. 



It was found that thick, heavy coating 

 prevented both the issuance and the en- 

 trance of about 95 per cent to 98 per cent 

 of the insects, the degree of eflaciency de- 

 pending upon the thoroughness of the 

 application. Asphaltum does not pene- 

 trate, crack, deteriorate, or bind the tree, 

 since it yields to the slightest pressure. 

 Four years of experimenting have not 

 shown the least injury. 



The material is applied warm with a 

 brush from five inches below to five inches 

 above the ground. It is easier to apply 

 two or more coatings than to try to put 

 on more at one time than will adhere firm- 

 ly. The first coating will harden very 

 quickly and the second can be applied 

 without loss of time. Two coatings are 

 generally sufficient unless the bark is very 

 rough. But in any case a thick, uniform 

 covering is absolutely necessary for the 

 best results. 



Borers are seldom uniformly distrib- 

 uted over an orchard. Small blocks of 

 trees here and there may be badly in- 

 fested and the most of the orchard com- 



*U. S. Department Agriculture Farmers Bul- 

 letin 517. 



