DISEASES AND PESTS OF PLANTS. 55 



Control. In order to prevent injury from this insect, it is necessary to prevent 

 the larvae from reaching the underground portion of the tree. This is accomplished 

 by encircling the trunk at the ground with a flexible soil-covering mat which must 

 be impenetrable to the borers and impenetrably sealed to the tree. Mr. W. M. Scott, 

 late State Entomologist of Georgia, and Mr. E. B. Blakeslee, of Washington, D.C., 

 have both adopted the same method of control as the result of continuous indepen- 

 dent experiments. 



The following is a summary of Mr. W. M. Scott's method as described by him 

 at a meeting of the American Association of Economic Entomologists : Tar-felt mats 

 16 inches in diameter are used. Cut a hole in the centre of each mat to conform to 

 the diameter of the trees, and slit from the hole to the outer edge. The soil is first 

 mounded somewhat around the tree and the protector placed over the mound. The 

 slit edges are lapped and glued together with a viscous material, and the protector 

 is sealed to the tree with the same material, completely filling all openings, so that 

 it is impossible for the borers to reach the soil without crawling away from the tree 

 beyond the outer edge of the protector. The viscous material for effecting an absolute 

 sealing to the tree is an essential feature of the protector. Mr. W. M. Scott has 

 applied for a patent on the sealing medium he used ; Mr. Blakeslee has found the use 

 of tanglefoot successful. 



THE PEACH-TWIG BORER (Anarsia Uneatella). 



This insect is of considerable importance in the peach-growing sections of British 

 Columbia. The insects hibernate in the form of immature larvae in cells just under 

 the bark, the top of the cells extruding from the bark and covered with frass. These 

 cells are built in the crotches of the trees. In the first warm days of spring, when 

 the buds are opening, the larvae leave their cells and commence feeding on the buds, 

 and, later, frequently bore down the young terminal twigs a distance of 2 or 3 inches, 

 killing them, and thereby injuring the trees. Later in the season larvae enter the 

 fruit, making it unmarketable. If left unchecked extensive losses will result. Peach- 

 orchards close in, which have been cut up into town lots, have been observed to be 

 a great source of infestation. By actual count one seven-year-old peach-tree on a 

 neglected unoccupied lot was found to have 9G per cent, of the fruit infested. Prunes 

 are also attacked. There are several broods each year. More information is 

 required both on the life-history of this insect and its control. 



Control. The remedies at present recommended are the dormant spray of lime- 

 sulphur, 1 part to 10 parts of water, applied just before the buds open. Care must 

 be taken to thoroughly saturate the crotches of the trees. During the last week of 

 July an application of arsenate of lead, 3 Ib. to 50 gallons of water, might be applied, 

 particularly on the fruit ; this will prevent a large percentage of the larvae from 

 entering the fruit. 



THE COTTONY MAPLE-SCALE (Pulvinaria innumerabilis) . 



This scale has been unusually numerous both in the Lower Okanagan country 

 and at the Coast the last two years. It is usually kept well in check by natural 

 enemies. Should a severe infestation occur, endangering the health of shade-trees, 

 control methods should be adopted to protect the trees and also prevent migration 

 to orchard trees. This insect is single-brooded. The young scales hatch from June 

 to early July, according to locality, and settle on the twigs of maple and other shade- 

 trees, and occasionally on fruit-trees. 



Control. Forty-per-cent. nicotine sulphate, 1 part to 1,000 parts of water, plus 

 5 Ib. of whale-oil soap to each 100 gallons of solution. Apply in the early spring 

 with a power-sprayer. In orchards they should be well controlled with the usual 

 spring application for aphides. 



THE RASPBERRY-ROOT BORER (Bertibecla marginata). 



This insect is beginning to appear in injurious numbers in British Columbia. 

 The adult insect is a clear-winged moth bearing some resemblance to a wasp. The 



