Electrophysiological and behavioral responses Dendroctonus frontalis and D. terebrans (Coleoptera: Curculionidae) to resin odors of host pines (Pinus spp.)

Semiochemicals for management of the southern pine beetle (Coleoptera: Curculionidae: Scolytinae): successes, failures, and obstacles to progress

“…However, due to difficulty in obtaining this material, this component has changed to a 2:1 combination of host monoterpenes alpha-pinene and beta-pinene, which typically are the two dominant resin monoterpenes of the southern pine beetle's preferred hosts (Mirov 1961). alpha-Pinene and beta-pinene individually are synergists of the aggregation pheromone (Staeben et al 2015;Munro et al 2020); however, the superiority of this particular compound pairing and ratio has not to our knowledge been demonstrated. Inclusion of additional host odour components (e.g., 4-allylanisole; Munro et al 2020) and adjustment of their enantiomeric composition (e.g., favouring the ()-enantiomer of alpha-pinene (Staeben et al 2015)) might further increase lure potency.…”

“…The most common trap design used operationally for southern pine beetle detection and monitoring is the 12-or 16-unit black multiple-funnel trap (Lindgren 1983). However, a range of trap designs (e.g., funnel, slot traps, and cross-vane traps) have all proven effective for trapping the beetle (Moser and Browne 1978;McCravy et al 2000;Munro et al 2020). McCravy et al (2000) found Theyson slot traps (Niemeyer et al 1983) to be similar in effectiveness to 12-unit funnel traps for trapping southern pine beetle; however, to our knowledge, multiple-funnel traps have not been directly compared to other designs.…”

“…Southern pine beetles also produce nonmonoterpene attraction inhibitors acetophenone and 2-phenylethanol (Sullivan 2005;Sullivan et al 2007a). Other sources of anti-attractant semiochemicals for the beetle include host tree species (e.g., resin constituents 4-allylanisole and myrcene; Hayes et al 1994;Munro et al 2020) and nonhost tree species (Dickens et al 1992;Sullivan et al 2007a;Shepherd and Sullivan 2013).…”

“…Synthetic lures, including the recommended operational lure for southern pine beetle, may lack important, undiscovered attractive semiochemicals produced by mass-attacked trees. Since the 2000s, investigation of undiscovered semiochemicalsboth attractants and attraction inhibitorsfor the southern pine beetle has been aided by coupled gas chromatography-mass spectrometry and gas chromatography-electroantennographic detection, in particular (Sullivan 2005;Shepherd and Sullivan 2013;Niño-Domínguez et al 2015;Niño-Domínguez et al 2018;Munro et al 2020). Using this latter method, compounds within odour blends isolated from natural sources are separated and assayed individually for their capacity to stimulate the antenna of the target insect (Bjostad 1998).…”

“…Gas chromatography-electroantennographic detection is a rigorous means for detecting olfactory stimulants (ostensibly the only compounds capable of being semiochemicals) within such mixtures, and subsequent behavioural bioassays can be limited to just a subset of compounds. To date, the method has been used to screen for southern pine beetle olfactory stimulants produced by emerged beetles, attacking beetles, attack entrances, frass, and host resin (Sullivan 2005;Shepherd and Sullivan 2013;Niño-Domínguez et al 2015, 2018Munro et al 2020). The sensitivity and thoroughness of this chemical-detection approach has enabled identification of dozens of olfactory stimulants, and thus potential semiochemicals, for the beetle.…”