The role of lanierone in the chemical ecology ofIps pini (Coleoptera: Scolytidae) in California

Abstract

Five doses of lanierone (2-hydroxy-4,4,6-trimethyl-2,5-cyclohexadien-1-one) were tested with one dose of enantiomerically pure [99.4% (4R)-(-)] ipsdienol (2-methyl-6-methylene-2,7-octadien-4-ol) for activity as an aggregation pheromone ofIps pini (Say) in California. The response ofI. pini to 1 mg/day ipsdienol + 20 μg/day lanierone was significantly greater than the response to ipsdienol alone, but the response pattern did not demonstrate a clear dose-response relationship. The response to the highest dose of lanierone (2 mg/day) was significantly lower than the response to ipsdienol alone. Ipsdienol attracted significantly moreI. pini than a male-infested log. Lanierone did not alter the percentage of maleI. pini responding to ipsdienol alone. Neither sex ofI. pini orDendroctonus brevicomis LeConte from California produced detectable amounts of lanierone, but myrcene-aerated maleD. brevicomis produced 97.8%-(4S)-(+)-ipsdienol. The black-bellied clerid,Enoclerus lecontei (Wolcott) (Coleoptera: Cleridae) was attracted to lanierone when released with ipsdienol. Neither compound was attractive when released alone, proving synergism for the kairomone of this predator. Lanierone did not influence the response of the predatorsTemnochila chlorodia (Mannerheim) (Coleoptera: Trogositidae) andEnoclerus sphegeus (F.) (Coleoptera: Cleridae), which were attracted to all treatments containing ipsdienol.Tomicobia tibialis Ashmead (Hymenoptera: Pteromalidae) responded in significantly greater numbers to the male-infested log than it did to ipsdienol or ipsdienol + 20 μg/day lanierone.

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

“…The responses of I. pini to the enantiomers of ipsdienol have been reported from other North American locations (Raffa and Klepzig 1989;Herms et al 1991). In northern Minnesota, (+/−)-ipsdienol along with lanierone would be an effective pheromone to monitor the populations of I. pini (Teale et al 1991;Seybold et al 1992Seybold et al , 1995Miller et al 1997).…”

“…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).…”

Spatial Displacement of Release Point can Enhance Activity of an Attractant Pheromone Synergist of a Bark Beetle

“…In addition to synergists and inhibitors, bark beetles may also utilize "multifunctional" semiochemicals that are attractive or synergistic at low release rates but inhibitory at high ones (Rudinsky 1973;Borden et al 1987;Schlyter et al 1987a;Seybold et al 1992;Erbilgin et al 2003). Furthermore, bark beetle responses to certain attractive semiochemicals decline at very high release rates (Seybold et al 1992;Ross and Daterman 1998;Miller et al 2005).…”

“…Furthermore, bark beetle responses to certain attractive semiochemicals decline at very high release rates (Seybold et al 1992;Ross and Daterman 1998;Miller et al 2005). Semiochemicals possessing such a parabolic dose-response curve should possess a single, optimally-attractive release rate; therefore the attractive activity of a bait exceeding this optimum dose could conceivably be enhanced by displacing it from the target (e.g., a trap), thereby effectively reducing its dose both at and downwind of the target.…”