Colonization, emergence, and survival of Hylurgopinus rufipes and Scolytus multistriatus (Coleoptera: Scolytidae) in insecticide-treated elm wood

Application of 0.1, 0.25, 0.5% (AI) chlorpyrifos, 2.0% (AI) carbaryl, or 0.1% (AI) permethrin to cut elm, either before or after gallery formation, significantly reduced brood production of Scolytus multistriatus (Marsham), the smaller European elm bark beetle, and Hylurgopinus rufipes (Eichhoff), the native elm bark beetle. Bioassays and residue analyses of treated elm, Ulmus americana L., showed that 0.5% (AI) chlorpyrifos was present and active for at least 11 months, thus providing ample time for cut elm to reach a point at which it was no longer suitable for beetle breeding. Application of 0.5% (AI) chlorpyrifos makes possible the long-term storage of undebarked, cut elm in a manner that is compatible with ongoing Dutch elm disease control programs.