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furrow should be ploughed just in front of them. A log dragged 

 along the furrow will kill the larvae. Grass and other vegetation 

 of no value should be sprayed with a mixture of Paris green and 

 water, 21b. to 50 U.S. gals. Growing grasses and forage crops should 

 be sprayed with 1 lb. lead arsenate in powder form, or 2 lb. in paste 

 form, to 50 U.S. gals, water. When maize is infested, the following 

 poison mixtures are recommended : 50 U.S. gals, water and 2 lb. 

 powdered arsenate of lead, or 4 lb. paste ; or 1 lb. Paris green and 

 2 lb. freshly slaked lime ; or 1 lb. arsenite of zinc and 1 lb. freshly 

 slaked lime. White arsenic must never be used on plants, as it 

 scorches them. Poison bait scattered over the fields is very efficacious. 

 For this purpose, 50 lb. bran is mixed with 1 lb. Paris green or 2 lb. 

 lead arsenate, and 2 U.S. gals, molasses and 6 chopped lemons are 

 added. 



Brooks (F. E.). Orchard Bark-beetles and Pinhole Borers, and how 

 to control them. — JJ . S. Dept. Agric, Washimjton, D.C., Farmers' 

 Bull. no. 763, 29th November 1916, 15 pp., 18 figs. [Received 

 27th February 1917.] 



A brief account is here given of the principal bark-beetles attacking 

 fruit trees and their control. Scolytus rugulosus, Ratz., is found both 

 in orchards and on wild fruit trees and always attacks weak or 

 unhealthy trees. In the northern States there are two generations 

 annually, while in the South there are probably three or four. The 

 adult beetle enters the trunk by making a round hole and burrows 

 parallel with the grain of the wood, depositing eggs as she goes. The 

 larvae burrow between the bark and sapwood, at right angles to the 

 main burrow. After feeding for 30 to 36 days they pupate in specially 

 constructed cells just beneath the surface of the sapwood. The 

 adults gnaw through the bark, making small round exit holes. In 

 healthy trees, a flow of gum from the wounds made by the adults 

 will often prevent the development of larvae, but as the tree is 

 weakened, the gum ceases to flow and leaves the tree open to the 

 depredations of the beetles. Natural enemies of this species include 

 the Chalcid, CJieiropackys colon, L., and other Hymenoptera, as well 

 as woodpeckers. 



Phloeotribus liminaris, Harr. (peach-tree bark-beetle) chiefly 

 attacks peach, cherry and sometimes plum trees. There are two 

 generations, which overlap, all stages of the insect being found at 

 one time. The adult burrows across the grain of the wood, depositing 

 eggs in httle pockets in the burrow. The larvae bore at right angles 

 to the main burrow and after about 30 days pupate within the bark, 

 whence the adults emerge after a few days. Both these species can 

 be checked by clearing away all damaged or unhealthy branches 

 and so hmiting the breeding-places. A thick coat of whitewash 

 should be applied to the trunks three times in the year, in early 

 spring, midsummer and autumn. A pint of crude cresylic acid added 

 to each 10 gallons of whitewash is an improvement and a handful 

 of salt to each pailful renders the mixture more adhesive. The 

 whitewash will not kill the insects already in the trees, but will check 

 oviposition and preserve the health of the tree. This has been found 

 the cheapest, simplest and most effective method of control. 



