DISPERSAL OF TOMICUS PINIPERDA (COLEOPTERA: SCOLYTIDAE) FROM OPERATIONAL AND SIMULATED MILL YARDS

Abstract

AbstractThe pine shoot beetle, Tomicus piniperda (L.), is an exotic pest that is regulated by federal quarantines in the United States and Canada. Mark–release–recapture experiments were performed with infested logs coated with fluorescent powder to determine if overwintering beetles in logs would leave a mill yard if infested logs were transported to sawmills in uninfested areas. Overwintering T. piniperda adults were marked with powder as they emerged in spring. Dispersal studies were conducted in four simulated mill yards and five operational sawmills to determine whether T. piniperda would colonize only the log pile in which they overwintered, fly to nearby log piles, or disperse beyond the mill yard. Each simulated mill yard was composed of 36 uninfested red pine logs, Pinus resinosa Ait. (Pinaceae), and 12 α-pinene-baited funnel traps set up to 100 m from a central release pile of six uninfested red pine and nine infested logs of Scotch pine, Pinus sylvestris L. At the five operational sawmills, baited funnel traps were set up to 400 m outside of each mill yard. Overall, 482 T. piniperda galleries were found on the experimental logs recovered from the four simulated mill yards combined. Tomicus piniperda adults dispersed and attacked the most distant logs at 100 m from the release point in the simulated mill yards. Likewise, adults were captured in baited funnel traps at distances up to 230 m in simulated mill yards and 250 m around operational sawmills. Although numbers of recaptured T. piniperda were generally low, in all cases some adults dispersed outside the mill yards despite the presence of abundant suitable breeding material. Therefore, logs containing overwintering adults pose a risk of spreading T. piniperda if not processed prior to initiation of spring flight.