Control of Sanninoidea exitiosa graefi (Hy. Edw.) on Apricots

Abstract

Studies were conducted on the control of the western peach tree borer, Sanninoidea exitiosa graefi (Hy. Edw.), in apricots with both soil fumigants and trunk sprays from 1955 through 1958. Results were first evaluated by caging the trees to trap emerging adults, later by counting empty cocoons or papal eases, and finally by strike counts in the early fall. The last-mentioned method was found to he the most practical. In the soil fumigation trials paradichlorobenzene, propylene dichloride, and tetrachloroethane gave good results. Ethylene dichloride was the least effective in these trials. Tetrachloro- chance although it killed borers, was extremely phytotoxic. Trunk treatments were made during the 1957 and 1958 sea- Soon. In 1957 Thiodan® (6,7,8,9,10-hexachloro-1,5,5a,6,9.9a,hexah, Hydro-6,9-methaono-2,4,3-benzodioxnthiepin-3-oxide) a no endrin Applied three times at monthly intervals gave good control. DDT was also effective, and three was little difference, between treatments at monthly or bimonthly intervals. The addition of a sticker to DDT did not improve its performance. Whitewash, applied to trees in late May, did not prevent borer attack. In 1958, Thiodan and endrin gave excellent control whether treated four times at monthly intervals or twice at bimonthly intervals. Guthion® (O,O-dimethly , s-(4-oxo-1,2,3-henz- triazine-3-methyl) phosphorodithioate) was effective at monthly intervals hut less so at bimonthly intervals, DDT was not so good as the above compounds, hut gave commercial control when applied four times at monthly intervals. A single treatment of dieldrin in June did not provide satisfactory control.