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Identification of the sex pheromone of the tree infesting Cossid Moth Coryphodema tristis (Lepidoptera: Cossidae).

Bouwer MC, Slippers B, Degefu D, Wingfield MJ, Lawson S, Rohwer ER - PLoS ONE (2015)

Bottom Line: Male antennae showed superior sensitivity toward Z9-14:OAc, Z7-tetradecenyl acetate (Z7-14:OAc), E9-tetradecenyl acetate (E9-14:OAc), Z9-tetradecenol (Z9-14:OH) and Z9-tetradecenal (Z9-14:Ald) when compared to female antennae.While we could show electrophysiological responses to single pheromone compounds, behavioral attraction of males was dependent on the synergistic effect of at least two of these compounds.Signal specificity is shown to be gained through pheromone blends.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry/Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0002, Gauteng, South Africa.

ABSTRACT
The cossid moth (Coryphodema tristis) has a broad range of native tree hosts in South Africa. The moth recently moved into non-native Eucalyptus plantations in South Africa, on which it now causes significant damage. Here we investigate the chemicals involved in pheromone communication between the sexes of this moth in order to better understand its ecology, and with a view to potentially develop management tools for it. In particular, we characterize female gland extracts and headspace samples through coupled gas chromatography electro-antennographic detection (GC-EAD) and two dimensional gas chromatography mass spectrometry (GCxGC-MS). Tentative identities of the potential pheromone compounds were confirmed by comparing both retention time and mass spectra with authentic standards. Two electrophysiologically active pheromone compounds, tetradecyl acetate (14:OAc) and Z9-tetradecenyl acetate (Z9-14:OAc) were identified from pheromone gland extracts, and an additional compound (Z9-14:OH) from headspace samples. We further determined dose response curves for the identified compounds and six other structurally similar compounds that are common to the order Cossidae. Male antennae showed superior sensitivity toward Z9-14:OAc, Z7-tetradecenyl acetate (Z7-14:OAc), E9-tetradecenyl acetate (E9-14:OAc), Z9-tetradecenol (Z9-14:OH) and Z9-tetradecenal (Z9-14:Ald) when compared to female antennae. While we could show electrophysiological responses to single pheromone compounds, behavioral attraction of males was dependent on the synergistic effect of at least two of these compounds. Signal specificity is shown to be gained through pheromone blends. A field trial showed that a significant number of males were caught only in traps baited with a combination of Z9-14:OAc (circa 95% of the ratio) and Z9-14:OH. Addition of 14:OAc to this mixture also improved the number of males caught, although not significantly. This study represents a major step towards developing a useful attractant to be used in management tools for C. tristis and contributes to the understanding of chemical communication and biology of this group of insects.

No MeSH data available.


Related in: MedlinePlus

GC-EAD responses of male antennae to gland extracts.The arrow indicates the peak of interest in the FID signal. Bottom is the response to the blank. (EAD response at 9.11 min: 1884 ± 435 μV, mean ± SE, N = 9)
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pone.0118575.g001: GC-EAD responses of male antennae to gland extracts.The arrow indicates the peak of interest in the FID signal. Bottom is the response to the blank. (EAD response at 9.11 min: 1884 ± 435 μV, mean ± SE, N = 9)

Mentions: GC-EAD investigation of the gland extracts revealed a large (1.9 ± 0.4 mV, N = 9, ± SE) EAD response of the male antenna to the only peak above the FID detection limit. This provided an estimate of the retention time that could be associated with physiologically relevant peaks in the chromatogram. The response was in most cases well above the noise level of the EAD detector and occurred at 9.11 minutes after optimization of the chromatographic parameters (Fig. 1). The retention index of this peak was calculated as 1797 and matched with the retention index of the standards for Z and E9-14:OAc on this system.


Identification of the sex pheromone of the tree infesting Cossid Moth Coryphodema tristis (Lepidoptera: Cossidae).

Bouwer MC, Slippers B, Degefu D, Wingfield MJ, Lawson S, Rohwer ER - PLoS ONE (2015)

GC-EAD responses of male antennae to gland extracts.The arrow indicates the peak of interest in the FID signal. Bottom is the response to the blank. (EAD response at 9.11 min: 1884 ± 435 μV, mean ± SE, N = 9)
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4380472&req=5

pone.0118575.g001: GC-EAD responses of male antennae to gland extracts.The arrow indicates the peak of interest in the FID signal. Bottom is the response to the blank. (EAD response at 9.11 min: 1884 ± 435 μV, mean ± SE, N = 9)
Mentions: GC-EAD investigation of the gland extracts revealed a large (1.9 ± 0.4 mV, N = 9, ± SE) EAD response of the male antenna to the only peak above the FID detection limit. This provided an estimate of the retention time that could be associated with physiologically relevant peaks in the chromatogram. The response was in most cases well above the noise level of the EAD detector and occurred at 9.11 minutes after optimization of the chromatographic parameters (Fig. 1). The retention index of this peak was calculated as 1797 and matched with the retention index of the standards for Z and E9-14:OAc on this system.

Bottom Line: Male antennae showed superior sensitivity toward Z9-14:OAc, Z7-tetradecenyl acetate (Z7-14:OAc), E9-tetradecenyl acetate (E9-14:OAc), Z9-tetradecenol (Z9-14:OH) and Z9-tetradecenal (Z9-14:Ald) when compared to female antennae.While we could show electrophysiological responses to single pheromone compounds, behavioral attraction of males was dependent on the synergistic effect of at least two of these compounds.Signal specificity is shown to be gained through pheromone blends.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry/Forestry and Agricultural Biotechnology Institute, University of Pretoria, Pretoria 0002, Gauteng, South Africa.

ABSTRACT
The cossid moth (Coryphodema tristis) has a broad range of native tree hosts in South Africa. The moth recently moved into non-native Eucalyptus plantations in South Africa, on which it now causes significant damage. Here we investigate the chemicals involved in pheromone communication between the sexes of this moth in order to better understand its ecology, and with a view to potentially develop management tools for it. In particular, we characterize female gland extracts and headspace samples through coupled gas chromatography electro-antennographic detection (GC-EAD) and two dimensional gas chromatography mass spectrometry (GCxGC-MS). Tentative identities of the potential pheromone compounds were confirmed by comparing both retention time and mass spectra with authentic standards. Two electrophysiologically active pheromone compounds, tetradecyl acetate (14:OAc) and Z9-tetradecenyl acetate (Z9-14:OAc) were identified from pheromone gland extracts, and an additional compound (Z9-14:OH) from headspace samples. We further determined dose response curves for the identified compounds and six other structurally similar compounds that are common to the order Cossidae. Male antennae showed superior sensitivity toward Z9-14:OAc, Z7-tetradecenyl acetate (Z7-14:OAc), E9-tetradecenyl acetate (E9-14:OAc), Z9-tetradecenol (Z9-14:OH) and Z9-tetradecenal (Z9-14:Ald) when compared to female antennae. While we could show electrophysiological responses to single pheromone compounds, behavioral attraction of males was dependent on the synergistic effect of at least two of these compounds. Signal specificity is shown to be gained through pheromone blends. A field trial showed that a significant number of males were caught only in traps baited with a combination of Z9-14:OAc (circa 95% of the ratio) and Z9-14:OH. Addition of 14:OAc to this mixture also improved the number of males caught, although not significantly. This study represents a major step towards developing a useful attractant to be used in management tools for C. tristis and contributes to the understanding of chemical communication and biology of this group of insects.

No MeSH data available.


Related in: MedlinePlus