Antennal olfactory responses of black turpentine beetle,Dendroctonus terebrans (Olivier), to bark beetle pheromones and host terpenes

Abstract

Electroantennograms (EAGs) were recorded from male and female black turpentine beetles,Dendroctonus terebrans (Olivier), exposed to bark beetle pheromones and host terpenes. The dose-response curves indicated similarities in the receptor mechanisms for both sexes for each compound. Antennal sensitivity was greatest toendo-brevicomin, which correlates with the importance of the compound in the behavior of the beetles. At above-threshold concentrations, EAGs were greatest toendo-brevicomin and frontalin, suggesting a large population of antennal receptors for these compounds. A large population of receptors would be expected for compounds that play such a significant role in this beetle's behavior. Beetles were also shown to have receptors that respond to theIps pheromones, ipsenol, and ipsdienol.

Electrophysiological responses of Dendroctonus armandi (Coleoptera: Curculionidae: Scolytinae) to volatiles of Chinese white pine as well as to pure enantiomers and racemates of some monoterpenes

“…Electroantennogram recordings EAG recordings were made using Ag-AgCl glass capillary electrodes filled with Ringer's solution (Barbosa 1974;Delorme and Payne 1990). The antennae were left on the head because they are very short, and it is hard to remove them without causing serious damage.…”

“…The remaining EAG procedures were similar to that of previous studies (Dickens et al 1985;Whitehead 1986;Delorme and Payne 1990;White and Hobson 1993;Shepherd et al 2008). A Pasteur pipette with a test compound was inserted into a small hole in the wall of a steel Mean EAG as a percentage of the standard (±SE) of male (M) and/female (F) D. armandi elicited by 12 compounds at different concentrations.…”

“…Myrcene is a kairomone for the mountain pine beetle, Dendroctonus ponderosae Hopkins (Billings et al 1976;Conn et al 1983;Libbey et al 1985;Borden et al 1987), and b-phellandrene increases the attraction of the pine engraver, Ips pini (Say), to its aggregation pheromone, ipsdienol (Miller and Borden 1990). The electroantennogram (EAG) response to host and non-host volatiles of bark beetles in the genus Dendroctonus has been well researched for a number of species, such as D. pseudotsugae Hopkins, D. terebrans (Olivier), D. ponderosae Hopkins, D. valens LeConte and D. brevicomis LeConte (Dickens et al 1985;Whitehead 1986;Delorme and Payne 1990;White and Hobson 1993;Shepherd et al 2008), with b-pinene, a-pinene, 3-carene, limonene and camphene being the principal volatiles involved (Byers 1995;Zhang and Schlyter 2004). Bark beetles, dispersing, selecting and landing on their various host trees, must discriminate between the different species of conifers occurring in a forest ecosystem, according to the various host volatiles emitted.…”

Modeling and Regression Analysis of Semiochemical Dose–Response Curves of Insect Antennal Reception and Behavior

“…8E-7, d = 4.456; male eq. F: a = 21.6, b = 117.7, c = 1.58E-7, d = 4.382. p Delorme and Payne (1990), Fig. 1A and B (μg) endo-brevicomin female eq.…”

“…It is apparent from many studies that dose-response curves of electroantennographic (EAG) voltages or neuronal spike frequencies, as well as bioassays in the laboratory, are plotted with a logarithmic scale on the x-axis (e.g., Al Abassi et al 2000; Anderson et al 1993;Byers 1983;Delorme and Payne 1990;Dickens et al 1997;Dolzer et al 2003;Gemeno et al 2003;Hilbur et al 2001;Moore 1981;Preiss and Priesner 1988;Schal et al 1990;. The plots of data points of increasing dosages usually are connected by straight lines, probably because the curvilinear relationships were poorly understood and complicated to plot.…”