Disruption of moth mating behaviour by olfactory and auditory cues

Research output: ThesisDoctoral Thesis (compilation)

Abstract

The impact of olfactory and auditory cues on the mating behaviour in two species of moths, Agrotis segetum (Noctuidae) and Plodia interpunctella (Pyralidae), was investigated to evaluate their potential use in integrated pest management. The flight behaviour of male A. segetum under natural and pheromone-based mating disruption conditions was monitored by harmonic radar. Individual males were equipped with a radar transponder, released and tracked in the field. Although the trap catch of males and the frequency of fertilised females were reduced by 79% and 62%, respectively, in pheromone-treated vs untreated plots, no drastic differences in flight behaviour between plots could be detected. The analysis was constrained by the fragmentation of tracks due to radar shadow. The potential to use sex pheromones for suppression of mating of P. interpunctella was evaluated. Mating was reduced by up to 93% in pheromone-treated tents compared to control tents, but no difference in mating disruption effect was observed when a four-component blend and the major component, Z9,E12-14:OAc, alone were used as disruptants or when the population density was altered. The risk of resistance evolution to pheromone-based mating disruption was studied by combined heritability and selection experiments. The heritability of the pheromone blend of P. interpunctella, measured as the ratio between Z9,E12-14:OAc and Z9,E12-14:OH, was estimated to 0.65, indicating a potential for a change of the trait via selection. However, no increase in mating frequency or change in pheromone blend composition compared to control moths was observed after three generations of selection in three separate lines, which indicates a limited potential for resistance evolution to the pheromone treatment. Flight tunnel studies were performed to study how ultrasound-triggered evasive behaviours of moths to attacking bats are influenced by sex pheromone stimulation. Male A. segetum and P. interpunctella showed less evasive reactions to ultrasound when flying towards highly adaptive sex pheromone sources compared to sources of lower adaptive value, indicating a trade-off between mate finding and predator avoidance. The quantitative reduction in evasive reaction to ultrasound exposure was estimated for P. interpunctella. At the frequency of best hearing (50 kHz), the threshold for flight stop of tethered males not stimulated with sex pheromone was at 70 dB SPL, whereas this threshold was increased to 95 dB SPL in free flying males stimulated with sex pheromone. Finally, the effect of high frequency sound on parameters involved in the odour-mediated mating behaviour of P. interpunctella was studied to evaluate the use of sound technology for population control. All phases in the reproduction process (female calling, male response to sex pheromone, female response to olfactory oviposition cues, mating activity) were affected by ultrasound stimulation.

Details

Authors
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Ecology

Keywords

  • Djurekologi, ultrasound, predation risk, selection, heritability, flight tunnel, harmonic radar, pest control, mating disruption, pheromone communication, Pyralidae, Lepidoptera, Noctuidae, Animal ecology
Original languageEnglish
QualificationDoctor
Awarding Institution
Supervisors/Assistant supervisor
Award date2002 Oct 25
Publisher
  • Chemical Ecology and Ecotoxicology, Department of Biology, Lund University
Print ISBNs91-7105-180-5
Publication statusPublished - 2002
Publication categoryResearch

Bibliographic note

Defence details Date: 2002-10-25 Time: 10:15 Place: October 25, 2002, in the Blue Hall, Ecology Building External reviewer(s) Name: Linn Jr., Charles E. Title: Dr Affiliation: Dept. Entomology, Cornell University, Geneva, N. Y., USA --- Article: Svensson, G. P., Valeur, P. G., Reynolds, D. R., Smith, A. D., Riley, J. R., Baker, T. C., Poppy, G. and Löfstedt, C. 2001. Mating disruption in Agrotissegetum monitored by harmonic radar. Entomologia Experimentalis et Applicata, 101:111-121. Article: Ryne, C., Svensson, G. P. and Löfstedt, C. 2001. Mating disruption of Plodia interpunctella in small-scale plots: effect of pheromone blend, emission rates and population density. Journal of Chemical Ecology, 27:2109-2124. Article: Svensson, G. P., Ryne, C. and Löfstedt, C. 2002. Heritable variation of sex pheromone composition and the potential for resistance evolution to pheromone-based control of the Indian meal moth, Plodia interpunctella. Journal of Chemical Ecology, 28:1443-1457. Article: Svensson, G. P., Löfstedt, C. and Skals, N. The odour makes the difference: male moths attracted by sex pheromones ignore the threat from predatory bats. Submitted. Article: Svensson, G. P., Löfstedt, C. and Skals, N. Pheromone-induced reduction in ultrasound-triggered predator defense in male Plodia interpunctella. Submitted. Article: Svensson, G. P., Skals, N. and Löfstedt, C. Disruption of the odour-mediated mating behaviour of Plodia interpunctella using high-frequency sound. Accepted for publication in Entomologia Experimentalis et Applicata. The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Chemical Ecology/Ecotoxicology (Closed 2011) (011006020)

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