CHEMICAL ECOLOGY Effect of Semiochemical Release Rate, Killing Agent, and Trap Design on Detection of Tetropium fuscum (F.) and Other Longhorn Beetles (Coleoptera: Cerambycidae) JON SWEENEY, 1, 2 JERZY M. GUTOWSKI, 3 JESSICA PRICE, 1 AND PETER DE GROOT 4 Environ. Entomol. 35(3): 645Ð654 (2006) ABSTRACT Release rates of a blend of monoterpenes (spruce blend) and ethanol signiÞcantly affected mean trap catch of Tetropium fuscum (F.), Tetropium castaneum L., and Tetropium cin- namopterum Kirby. Addition of an ethanol lure to traps baited with the spruce blend lure was necessary to attract T. castaneum and T. cinnamopterum and signiÞcantly increased attraction of T. fuscum. The combination of spruce blend and ethanol at high release rates had the highest mean catch of Tetropium spp. and was the only lure treatment that resulted in capture of T. fuscum and T. castaneum (in Poland) in every test block, suggesting it would be the best for detection surveys among the lures tested. The effect of trap design on mean catch of T. fuscum was inconsistent. In one experiment, the larger collapsible cross-vane Colossus trap caught about twice as many beetles as the IPM-Intercept trap, but in two other experiments, mean catch did not differ signiÞcantly. Type of killing agent in the collecting bucket signiÞcantly affected mean catch of T. fuscum. Traps with liquid killing agent (50/50 mixture of propylene glycol and deionized water plus 0.5 ml/liter of Kodak Photo-Flo 200 and 12.5 mg/liter of Bitrex) in the collecting bucket caught more beetles than traps with an insecticidal (dichlorvos) strip. Although any of cross-vane traps tested seem suitable for trapping several cerambycid species, the Colossus trap with liquid killing agent is recommended for use as a detection tool for T. fuscum because it caught similar or greater numbers than the other trap types. KEY WORDS semiochemicals, release rate, killing agent, Tetropium fuscum, Cerambycidae Expansion of global trade and intercontinental human movement during the 20th century have greatly ac- celerated the rate of accidental introductions of non- native species (Sailer 1978, Liebhold et al. 1995). Some of these alien species become invasive, i.e., they es- tablish, proliferate, and spread in their new habitat, and cause signiÞcant ecological and economic damage (Mack et al. 2000, Pimental et al. 2000, Nowak et al. 2001, Simberloff 2002). It is far more cost effective to prevent invasions through international regulatory measures than to effect postentry control (Mack et al. 2000). Once a species has established, its containment and eradication are possible (Hoelmer and Grace 1989, Mack et al. 2000), but probability of success decreases with increasing population size (Sharov and Liebhold 1998, Liebhold and Bascompte 2003). There- fore, early detection of alien invasive species, when populations are small, is critical to the success of erad- ication or containment programs (Liebhold and Bas- compte 2003). The brown spruce longhorn beetle, Tetropium fus- cum (F.) (Coleoptera: Cerambycidae), is a quarantine pest that was discovered near the port of Halifax, Nova Scotia, Canada, in 1999 (Smith and Hurley 2000). In Europe, T. fuscum infests mainly Norway spruce, Picea abies L. Karst., and is considered a secondary pest, breeding in recently felled trees or trees weakened by root rots or other factors (Juutinen 1955). In con- trast to the situation in Europe, T. fuscum seems to act more aggressively in Nova Scotia, where it is infesting and killing red spruce, P. rubens Sarg., white spruce, P. glauca (Moench) Voss, black spruce, P. mariana (Mill.) B.S.P., and Norway spruce (Smith and Humble 2000, Sweeney et al. 2001). In Norway, 5% of T. fuscum–infested trees appeared healthy with green crowns (Juutinen 1955), whereas 67% of T. fuscum– infested spruce in Halifax had green and healthy crowns, with copious resin ßow down the stem (OÕLeary et al. 2003). OÕLeary et al. (2003) found that trees with reduced growth rate and low vigor were more susceptible to T. fuscum than faster-growing trees and concluded the beetle was a threat to spruce forests in North America that were undergoing peri- ods of stress and suppressed growth caused by drought, defoliator outbreaks, or a complex of factors. Because T. fuscum is considered a threat to the health of CanadaÕs spruce forests, and the infestation in Hali- fax represents the only known population of the beetle 1 Natural Resources Canada, Canadian Forest ServiceÐAtlantic For- estry Centre, PO Box 4000, Fredericton, NB, Canada E3B 5P7. 2 Corresponding author, e-mail: jsweeney@nrcan.gc.ca. 3 Forest Research Institute, Department of Natural Forests, 17-230 Bialowiez ˙ a, Poland. 4 Natural Resources Canada, Canadian Forest ServiceÐGreat Lakes Forestry Centre, 1219 Queen Street E., Sault Ste. Marie, ON, Canada P6A 2E5.