Scots Pine, Control of Summer Generation Crawlers of a Pine Needle Scale, Carroll Co., OH, 1981

Pinus sylvestris (2-2.5 m high) growing in a Christmas tree plantation were chosen for evaluating toxicity of an experimental pyrethroid Insecticide against crawlers of the summer (= July) generation. Infested trees with newly hatching crawlers were sprayed Jul 22, using a KWH mistblower operating at maximum rpm's to deliver ca. 946 ml of finished spray to each of 4, single-tree replicates per treatment. Ambient temperature was 21°C with partly cloudy skies and a 6-8 kph breeze. Settled first instars, crawlers, and eggs were present during spraying. Treatment effectiveness was evaluated Aug 4 by collecting infested needle fascicles and inspecting them with the aid of a binocular microscope in the field for living and dead settled first instars. Counts were made from at least 3 fascicles; the first 100 settled nymphs observed were used for analysis.