164 



Fulton (B. B.). Tne Fruit-tree Leaf-roller. Report on Progress 

 of Investigations. — oyd Crop Pest & Horiic. Kept.. 1915-20, 

 Oregon Agric. Expt. Sta., Corvallis, 10th January 1921, pp. 82-88, 

 4 figs. 

 The fruit-tree leaf-roller [Tortrix argyrospila] was first observed 

 to be destructive in Oregon in 1912, and rapidly became one of the 

 most injurious fruit pests of the State, sometimes defoliating whole 

 trees and spoiling two seasons' crops by preventing the formation 

 of fruit buds. While apple is the preferred food, cherry, plum, prune 

 and pear trees are also attacked, but seldom peaches. The oblique- 

 banded leaf-roller [T. rosaccana] is frequently associated with T. 

 argyrospila, but has not been known to do any serious damage. T. 

 argyrospila passes more than nine months of the ytds in the egg-stage 

 attached to the bark of the tree, and hatches when the buds are in 

 the cluster stage, the young larvae generally entering the blossoms 

 and webbing the stamens together. Later, they fasten the leaves 

 together to form a nest. Pupation occurs within the web, the moths 

 beginning to appear from late June to mid- July, according to the locality, 

 the species occurring in all parts of the State. Seven different para- 

 sites have been bred from this leaf-roller, and a soldier-bug is an 

 active predator, but these enemies are not a sufhcient check. The 

 most successful remedy as yet tried is a spray of heavy miscible oil, 

 8 gallons to 100, applied after the buds show green at the tip 

 and before the blossom cluster buds begin to spread. 



Robinson (R. H.). Chemical and Physical Properties of the Arsenates 

 of Lead.— 5r^ Crop Pest & Horiic. Kept., 1915-20, Oregon 

 Agric. Expt. Sta., Corvallis, 10th January 1921, pp. 89-94, 

 1 plate, 1 fig. 



The results of various tests with different commercial brands of 

 lead arsenate are given. All those tested were practically the same 

 in chemical composition, safe in use and probably equally efficient. 

 The present investigation into the phj^sical properties indicates that 

 there is an appreciable difference in the size of the particles, in the 

 proportion of large and small particles, and their suspension qualities. 

 The addition of a spreader seemed to cause further sub-division of 

 clusters of arsenical particles and to hold them in suspension for a 

 long time. An efficient spreader should also cause the drops to 

 flatten out and spread over a larger area. Only spraying tests in the 

 field will prove whether the addition of a spreader increases the efficacy 

 of an arsenical spray. 



LovETT (A. L.). The Pear Thrips {Taeniothrips inconsequens, Uzel). 

 — 3rd Crop Pest & Hortic. Kept., 1915-20, Oregon Agric. 

 Expt. Sta., Corvallis, 10th January 1921, pp. 95-102, 6 figs. 



Taeniothrips inconsequens (pear thrips) was first observed in de- 

 structive numbers in Oregon in 1919, though it had probably been 

 introduced some years previously. An account of its life-historj'-, 

 habits, food-plants and the injury it causes is given [R.A.E., A, iii, 

 461. etc.]. Many spraying tests were planned for 1920, but owing 

 to climatic conditions this thrips was not numerous, and spraying 

 was impossible or of little value. Until thorough trials have been 

 made in Oregon, it is proposed to adopt the spraying practices followed 

 in British Columbia, and a spray calendar on these lines is appended. 



