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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 response of male antennae to one of the glass wool extracts of the female headspace.The arrow indicates the peak of interest in the FID signal and the presence of a smaller second response. A: The response to the blank. B: The averaged response of four different sample recordings. (EAD response at 5.61 min: 590 ± 50.33 μV, mean ± SE, N = 4)
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pone.0118575.g002: GC-EAD response of male antennae to one of the glass wool extracts of the female headspace.The arrow indicates the peak of interest in the FID signal and the presence of a smaller second response. A: The response to the blank. B: The averaged response of four different sample recordings. (EAD response at 5.61 min: 590 ± 50.33 μV, mean ± SE, N = 4)

Mentions: Two electroantennographic responses were observed for the glass wool extracts from the female headspace (Fig. 2). The larger response of the two occurred at 5.61 minutes. The retention index of this peak was calculated as 1671.7 on this system. Literature comparison of this retention index suggested that the compound was either E11-14:OH or Z10-14:OH [15] and it was later confirmed to be Z9-14:OH. The smaller response occurred at 6.38 minutes (RI = 1799.0) and coincided with the elution time of Z9-14:OAc on the GC-EAD system. No chromatographic peak could be observed at this response time on both the GC-EAD and GC-MS systems.


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 response of male antennae to one of the glass wool extracts of the female headspace.The arrow indicates the peak of interest in the FID signal and the presence of a smaller second response. A: The response to the blank. B: The averaged response of four different sample recordings. (EAD response at 5.61 min: 590 ± 50.33 μV, mean ± SE, N = 4)
© Copyright Policy
Related In: Results  -  Collection

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

pone.0118575.g002: GC-EAD response of male antennae to one of the glass wool extracts of the female headspace.The arrow indicates the peak of interest in the FID signal and the presence of a smaller second response. A: The response to the blank. B: The averaged response of four different sample recordings. (EAD response at 5.61 min: 590 ± 50.33 μV, mean ± SE, N = 4)
Mentions: Two electroantennographic responses were observed for the glass wool extracts from the female headspace (Fig. 2). The larger response of the two occurred at 5.61 minutes. The retention index of this peak was calculated as 1671.7 on this system. Literature comparison of this retention index suggested that the compound was either E11-14:OH or Z10-14:OH [15] and it was later confirmed to be Z9-14:OH. The smaller response occurred at 6.38 minutes (RI = 1799.0) and coincided with the elution time of Z9-14:OAc on the GC-EAD system. No chromatographic peak could be observed at this response time on both the GC-EAD and GC-MS systems.

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