Synergism of Turpentine and Ethanol as Attractants for Certain Pine-Infesting Beetles (Coleoptera)

Abstract

Responsesof seven species of pine-infesting beetles to traps baited with either turpentine, ethanol, turpentine and ethanol released from separate dispensers,or a 1:1solution of turpentine and ethanol released from one dispenser were assessedin three fieldexperiments. The weevil species, Pachylobius picivorus (Germar), and the cerambycid pine sawyer, Monochamus carolinensis (Olivier), were attracted to turpentine and were unaffected by the addition of ethanol. The ambrosia beetle, Xyleborus affinis Eichhoff, responded to ethanol alone but was not attracted to turpentine, nor did the presence of turpentine significantly affect its response to ethanol. The remaining four species displayed responses to turpentine that were enhanced by the addition of ethanol, but in different ways according to the method of deployment. Hylobius pales (Herbst) weevils and M. titillator (F.) sawyers displayed greatest attraction to turpentine and ethanol whether they were released from side-by-side dispensers or as a solution from one dispenser. The black turpentine beetle, Dendroctonus terebrans (Olivier), displayed the highest response to turpentine and ethanol in solution. The ambrosia beetle, X. pubescens Zimmermann, responded in low numbers to turpentine or ethanol deployed singly, but displayed an enhanced response (20-fold increase) to turpentine and ethanol deployed side-by-sideand an even greater response (60-fold increase) to a solution of turpentine and ethanol. Reasons for increased responses by some species to a solution of turpentine and ethanol over the two released separately are not clear; they may lie in different dosagesor evaporation rates of volatilesin the field. Laboratory analyses of trapped headspace volatiles from dispensers containing only turpentine and those containing a solution of turpentine and ethanol revealed no differences in the amounts of four principal monoterpene hydrocarbons (a-pinene, camphene, }3-pinene,and limonene) released over time. The synergistic effect of turpentine and ethanol for some speciesand not others may point to ecological differences between species with regard to the condition of preferred host material.

Host-Tree Chemistry Affecting Colonization in Bark Beetles

“…Ethanol, probably released by microorganisms in decaying woody tissue (Graham, 1968;Moeck, 1970;Cade et al, 1970) and stressed plants (Kimmerer and Kozlowski, 1982), is attractive to a wide variety of species of bark beetles (Moeck, 1970(Moeck, , 1981Magema et al, 1982;Montgomery and Wargo, 1983;Kohnle, 1985;Klimetzek et al, 1986;Schroeder 1987Schroeder , 1988Schroeder and Eidmann, 1987;Phillips et al, 1988;Volz, 1988;ChCnier and Philoghe, 1989;Schroeder and Lindelow, 1989;Byers, 1992a). Primary alcohols other than ethanol have not been reported as being attractive to scolytids.…”

“…a-pinene, myrcene, terpinolene, P-pinene) (Fig. 5.4) and turpentine are also attractive to a large number of bark beetle species (Byers et al, 1985;Byers 1992a;Phillips et al, 1988;Schroeder, 1988;Chtnier and Philoghe, 1989;Schroeder and Lindelow, 1989;Miller and Borden, 1990;Phillips, 1990;Hobson et al, 1993). Synergism between ethanol and various monoterpenes (or turpentine) is also of widespread occurrence (Nijholt and Schonherr, 1976;Kohnle, 1985;Vitt et al, 1986;Phillips et al, 1988;Volz, 1988;Schroeder, 1988;Chtnier and Philogbe, 1989;Schroeder and Lindelow, 1989;Phillips, 1990).…”

“…5.4) and turpentine are also attractive to a large number of bark beetle species (Byers et al, 1985;Byers 1992a;Phillips et al, 1988;Schroeder, 1988;Chtnier and Philoghe, 1989;Schroeder and Lindelow, 1989;Miller and Borden, 1990;Phillips, 1990;Hobson et al, 1993). Synergism between ethanol and various monoterpenes (or turpentine) is also of widespread occurrence (Nijholt and Schonherr, 1976;Kohnle, 1985;Vitt et al, 1986;Phillips et al, 1988;Volz, 1988;Schroeder, 1988;Chtnier and Philogbe, 1989;Schroeder and Lindelow, 1989;Phillips, 1990). These compounds are not only important for primary attraction to plants, but also may play a role in enhancing the bark beetles' response to aggregation pheromone (Bedard et al, 1969(Bedard et al, , 1970Pitman et al, 1975;McLean and Borden, 1977;Borden et al, 1980Borden et al, , 1981Paiva and Kiesel, 1985;Byers et al, 1988;Miller and Borden, 1990).…”

Application of Semiochemicals to Assess the Biodiversity of Subcortical Insects following an Ecosystem Disturbance in a Sub-boreal Forest

“…In many cases, semiochemicals were first identified from western North American bark beetle species (Silverstein et al 1966Wood et al 1967;Furniss et al 1972;Baker et al 1977;Birch et al 1980;Bowers et al 1991;Hobson et al 1993;Borden et al 1996;Camacho et al 1998;Holsten et al 2000), and baits in other regions of the continent often are based on these research results. In addition to targeting specific species, semiochemicals also can be used to assess the diversity of predators and commensals that exploit the attractants of subcortical insects as host-finding kairomones (Dixon and Payne 1980;Phillips et al 1988;Chénier and Philogène 1989;Seybold et al 1992;Raffa 2000, 2005;.…”

“…Finally, few studies have explored the full range of subcortical forest insects by using traps baited with semiochemicals. Most semiochemical studies have focused on either single subcortical species (e.g., Bedard et al 1980;Borden et al 1996); their associated predators (e.g., Seybold et al 1992;; or on a small subset of subcortical insect families (e.g., Phillips et al 1988;Chénier and Philogène 1989;Miller and Rabaglia 2009).…”