Control of Colorado Potato Beetle with Hag 107 and MK 936 Sprays on Potatoes, 1982

‘Russet Burbank’ potatoes were planted on Apr 20 in Ritzville silt loam soil pH 6.2, organic matter 1.6%, at Yakima, WA. An established infestation of Colorado potato beetle (CPB) was present at the time of insecticide application. HAG 107 and MK 936, a streptomycete-derived insecticide, were applied with a 2-row 4-flat fan nozzle, portable boom CO2powered sprayer at 50 psi in 50 gal of water per acre on Jul 21. Each plot was 2 rows (34 inch) wide and 25 ft long. Each treatment was replicated 4 times in a randomized complete block design. The potato crop was sprinkler irrigated with 0.75 acre inch applied on Aug 4 and again on Aug 9 (13 and 19 days post treatment). The number of dead and live CPB per sq m of soil surface per plot were counted on Jul 22 (1 day post treatment). The number of CPB adults and larvae on the plants of 2 m of row were counted on Jul 22 and Jul 27 (1 and 6 days post treatment). The percent of plant defoliation per plot was recorded on Jul 21, 27 and Aug 11 or 0, 6 and 21 days post treatment.