Evaluation of Relative Speed of Incapacitation of Elm Bark Beetle Insecticides, Laboratory Bioassay, 1993

Branches of Siberian elm were sprayed 17 Aug to point of run-off with insecticides to evaluate their relative speed to incapacitate elm bark beetle adults. High-end labelled rates for foliar application were used for all treatments. Treated branches were collected 23 Aug and 13 Sep and cut twigs placed in petri dishes with beetles. In each trial, elm bark beetles were collected with pheromone-baited Lindgren funnels and placed in groups of 10 in petri dishes and given portions of the treated branches as food. In the first trial 6 replications were used; only 3 were used in the second trial due to declining bark beetle numbers. Mortality and morbidity was assessed at three intervals within 1 DAT. Morbidity was determined as being unable to walk, but still capable of some movement.