Taxus, Fletcher Scale Control, Lake Co., Oh, 1984

Taxus media ‘Hicksi’ (0.3 m tall) growing in 3-gal containers and infested with Lecanium fletcheri were used for evaluating effectiveness of insecticides against established first and second stage scale nymphs. Sprays were applied with a KWH backpack mistblower on aperature setting 4 at half throttle for 30 sec to deliver ca. 930 ml of finished spray to each of 4, single-plant replicates. All plants were tightly sheared, necessitating this volume to approach runoff. Sprays were applied 13 Aug under cloudy skies at 24°C with a breeze gusting to 15-20 kph. Samples were taken 20 Aug by collecting 5 infested twigs from each plant and placing them in separate paper bags, transported under refrigeration to the laboratory. Treatment effectiveness was evaluated by determining viability of all nymphs on 25 infested needles, with the aid of a dissecting microscope.