Cotoneaster, Efficacy of Selected Pesticides Against an Aphid, Lake CO., OHIO, 1990

Cotoneaster growing in 3-gal (11.7 liter) containers at a nursery in Lake Co., OH, was used to evaluate efficacy of selected pesticides against aphids. A COa compression sprayer at 30 psi with a single Teejet SS8004 flat-fan nozzle was used to apply treatments to run-off. Two tests were conducted at separate nurseries in Lake Co. In the first test infested plants were selected at random and placed in groups of 4, single-plant replicates per treatment. Only one application was applied 3 Jul under sunny skies, 27°C, and 16-24 km/h winds. In the second test infested plants were selected at random and placed in groups of 5, single-plant replicates per treatment. Two applications were made. The first application was 18 Jul under sunny skies, 29°C, and 10-15 km/h winds and the second application was to selected plants 30 Jul under sunny skies, 25°C, and 10-15 km/h winds. Plants received over-head irrigation every other day or as needed. Treatments in tests 1 and 2 were evaluated 7 and 10 DAT, respectively, by removing four, 10-13 cm long branch tips from each of the 4 or 5 replicates. Samples were placed in plastic bags and transported, in coolers, to the laboratory. All samples were processed by passing them through an aphid brusher 6 times to dislodge aphids to a rotating glass plate coated with Tween-20. Dislodged aphids were counted with the aid of a binocular dissecting microscope.