A Male-Predominant Cuticular Hydrocarbon, 7-Methyltricosane, is used as a Contact Pheromone in the Western Flower Thrips Frankliniella occidentalis
- 786 Downloads
In a laboratory bioassay, adult female Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) spent more time near filter paper disks that had been exposed to adult males than near unexposed disks; this effect was not observed on disks exposed to adult females. The response could only partly be explained by the known male-produced aggregation pheromone, neryl (S)-2-methylbutanoate, suggesting the presence of an unknown male-produced compound. In gas chromatography/mass spectrometry analyses, 7-methyltricosane was detected on disks exposed to males, but not on disks exposed to females. Extracts of cuticular lipids also showed relatively large amounts of 7-methyltricosane on males, whereas only trace amounts were found on females and none on larvae. Bioassays of synthetic 7-methyltricosane showed that adults responded only after contact. The response to this compound was clearly different from that to n-tricosane or hexane-only controls. Females that contacted 7-methyltricosane on glass beads stayed in the vicinity and frequently raised the abdomen, a behavior that rejects mating attempts by males. Males stayed in the vicinity and wagged the abdomen sideways, a behavior used in fighting between males. This is the first identification of a contact pheromone in the order Thysanoptera.
KeywordsThysanoptera Thripidae Neryl (S)-2-methylbutanoate Mating behavior Fighting behavior Video tracking
Oladele Olaniran thanks the Education Trust Fund, Nigeria and Ladoke Akintola University of Technology, Ogbomoso, Nigeria for providing a training fellowship. Akella Sudhakar acknowledges the support of the European Union under a Marie Curie International Incoming Fellowship (Project No: 252258, Project Acronym: PERFECT). David Hall was funded by Defra Horticultural LINK Project HL 01107. We thank Dudley Farman (NRI) for preparing filter disks and running the GC/MS analyses of exposed disks.
- Dublon, I. A. N. 2009. The Aggregation Pheromone of the Western Flower Thrips. PhD dissertation, Keele University, UK.Google Scholar
- Ellington, C. P. 1980. Wing mechanics and take off preparation of Thrips (Thysanoptera). J. Exp. Biol. 85:129–136.Google Scholar
- Kirk, W. D. J. and Hamilton, J. G. C. 2010. The aggregation pheromones of thrips. (Abstract, IXth International Symposium on Thysanoptera and Tospoviruses, 31 August–4 September, 2009). J. Insect Sci. 10(166):19–20.Google Scholar
- Lewis, T. 1997. Thrips as Crop Pests. CAB International, Wallingford.Google Scholar
- Mound, L. A. 2009. Sternal pore plates (glandular areas) of male Thripidae (Thysanoptera). Zootaxa 2129:29–46.Google Scholar
- Terry, I. and Schneider, M. 1993. Copulatory behaviour and mating frequency of the western flower thrips, Frankliniella occidentalis (Insecta: Thysanoptera). Zool. (J. Pure Appl. Zool.) 4:339–354.Google Scholar
- Zhao, C.-Y., He, Y.-R., Zhong, F., Gao, Y., Qi, G.-J., Shao, X.-Y., and Lv, L.-H. 2011. Analysis of cuticular hydrocarbons of Frankliniella occidentalis. Chin. J. Appl. Entomol. 48:536–541.Google Scholar