Wednesday, December 13, 2006

Life table development for red oak borer, Enaphalodes rufulus (Haldeman) (Coleoptera: Cerambycidae) in the Ozark Mountains of Arkansas

Larry D. Galligan, lgallig@uark.edu1, Melissa K. Fierke, mfierke@uark.edu1, Damon J. Crook, damon.j.crook@aphis.usda.gov2, and Fred M. Stephen, fstephen@uark.edu1. (1) University of Arkansas, Department of Entomology, 319 Agriculture Building, University of Arkansas, Fayetteville, AR, (2) USDA-APHIS-PPQ, Otis Pest Survey Detection and Exclusion Laboratory, Bldg 1398, Otis ANGB, MA

Construction of life tables is an important component in understanding insect population dynamics. A recent outbreak of red oak borer, Enaphalodes rufulus (Haldeman), a native wood-boring insect, was implicated as a major contributor to an oak mortality event in the Ozark National Forest of northwest Arkansas. Life tables were developed to evaluate mortality for the 2003 and 2005 red oak borer cohorts. Northern red oaks, Quercus rubra L., were grouped into three red oak borer infestation history classes, low, moderate and high infestation. Trees were intensively and extensively sampled to determine densities of phloem-feeding galleries initiated and live larvae for five time periods: active 1, quiescent 1, active 2, quiescent 2, and active 3. A majority of mortality could not be attributed to a specific mortality factor. Known factors included cannibalism, predation by wireworms, carpenter worms, and ants. Other factors included mortality associated with nitidulid larvae, pathogens (e.g., Beauveria bassiana), nematodes, and hymenopterous parasitoids.

Species 1: Coleoptera Cerambycidae Enaphalodes rufulus (red oak borer)
Species 2: Fagales Fagaceae Quercus rubra (northern red oak)