Scots Pine, Pine Needls Scale Control, Carroll Co., Ohio, 1980

Abstract

Abstract Pinus sylvestris 2-3 m high growing in a Christmas tree plantation were used to evaluate effectiveness of selected insecticides against crawlers. Infested trees were selected and sprayed May 23, using a KWH backpack mistblower delivering ca 500 ml of finished spray per each of 4, single tree replicates/ treatment. Ambient temperature during application was 24-26°C with cloudy skies and a slight (5-7 kph) breeze. Treatment effectiveness was evaluated 6 days post-treatment by removing several crawler-infested needle fascicles from each tree and placing them in coin envelopes. Samples were transported in an air conditioned vehicle to the laboratory where mortality counts were made using a binocular microscope and counting the number of dead and alive settled nymphs of the first 100 encountered. On May 30, different trees were selected and treated with the most promising insecticides used on May 23. Application and evaluation were conducted in the aforementioned manner, except 3, single tree replicates were used. Sprayed and unsprayed check trees were sampled Jun 5.