Scots Pine, Pales Weevil and Northern Pine Weevil Control, Carroll Co., Ohio, 1980

A stand of Scots pine Christmas trees, partially harvested in 1979, was used to evaluate efficacy of selected insecticides as stump treatments to limit reproduction of regeneration weevils. Three, 5-stump replicates arranged in a randomized complete block design were treated April 24 when the temperature was 16-18°C with clear skies and a slight breeze. Tordon was applied to only 5 stumps scattered throughout the stand. Hudson compression sprayers were used to apply ca 180 ml of finished spray to each stump. On May 4, additional stumps were treated in the aforementioned manner at the same location to evaluate 2 rates of Furadan 4F. In this case, 20 consecutive stumps in a row were treated with each rate (=4, 5-stump reps/trt.). Stumps were sampled Aug 8-Nov 7 by stripping bark to first lateral roots and counting larvae and depressions in the xylem that indicated presence of chip cocoons. No attempt was made to distinguish chip cocoons of the 2 weevil species.