Date of Award:
Master of Science (MS)
Michael J. Jenkins
A field experiment tested the effectiveness of carbaryl and two pyrethroid insecticides, cyfluthrin and esfenvalerate, in protecting high-value Engelmann spruce trees from attack by Dendroctonus rufipennis Kirby. Carbaryl suspension at the 2% registered rate and a reduced rate of 1 % were both effective in protecting Engelmann spruce from attack by D. rufipennis through two pheromone baiting periods and 24 months following insecticide application . Cyfluthrin at 0.025% rate and esfenvalerate at 0.025 and 0.05% rates provided effective protection through one pheromone baiting and 12 months following insecticide application. Only cyfluthrin at 0.008% rate was judged ineffective protection 12 months following insecticide application.
A laboratory evaluation utilizing a 32-h bioassay on D. rufipennis adults determined all three insecticides were toxic by contact. Carbaryl and piperonyl butoxide bioassays testing synergism were inconclusive. The methodology presented provides a means for forest land managers to quantify insecticide toxicity and monitor for resistance development.
Johnson, Karen J., "Effectiveness of Carbaryl and Pyrethroid Insecticides for Protection of Engelmann Spruce from Attack by Spruce Beetle (Coleoptera: Scolytidae)" (1996). All Graduate Theses and Dissertations. 7311.
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