Disruption of odour-mediated behaviors in moths using olfactory and acoustic cues

Glenn Svensson

Glenn The use of species-specific infochemicals, pheromones, for mate finding is a common phenomenon among Lepidopteran species. Control of moth populations by sex pheromone treatments has been practised for more than 25 years and it has been successful for several species. This approach has advantages compared to traditional pest management using pesticides:
  • the specifity of the method is high, so beneficial organisms survive the treatment
  • pheromones are non-toxic compounds and thus not harmful to the environment

    • The purpose of using sex pheromones is not to kill but rather to disrupt the delicate mate finding process of males towards females. By permeating the atmosphere with high concentrations of synthetic sex pheromones in an area infected by the target species, males cannot track the signals produced by individual females due to the synthetic background of sex pheromone. Even if the treatment has been successful in some cases there have also been failures. In addition, many fundamental questions concerning the mechanisms behind the disruption behaviour are still unanswered.

    Another way to exploit a sensory system in moths for population control is to expose them to ultrasound pulses, mimicking calls from echolocating insectivorous bats. Many moths have evolved ultrasound-sensitive ears and defensive manouvres to be able to avoid attacking bats. By exposing moths to ultrasound (signalling a high predation risk) they may decrease their mobility, thus reducing the probability of finding a mate.

    My research projects focus on both genetic and behavioural aspects of pheromone- and ultrasound-based mating disruption in moths.
    1. Detailed studies of the flight behaviour of male turnip moths, Agrotis segetum,have been performed in areas with or without high doses of sex pheromones using the harmonic radar technique (in cooperation with the Natural Resources Institute, Malvern, UK, and IACR-Rothamsted, UK) (Svensson et al.).
    2. High doses of sex pheromones have been used to suppress matings of Indian meal moths, Plodia interpunctella,by up to 93% in small-scale experiments (Ryne et al., 2001).
    3. Heritability and selection studies on female sex pheromone production and mating ability under mating disruption conditions have been performed on Plodia interpunctella to estimate the potential for development of resistance to pheromone-based population control (Svensson et al., submitted).
    4. The effect of ultrasound on different parameters involved in the odour-mediated mating behaviour of Plodia interpunctella has been investigated (Svensson et al., unpubl.).
    5. The influence of olfactory (sex pheromone) and acoustic (bat call) cues on the flight behaviour of male Plodia interpunctella and Agrotis segetum will be investigated.
    Tagged Picture: Male Agrotis segetum equipped with a harmonic radar transponder. The weight of the tag is only 10 mg, i.e. less than 10 % of the weight of a male. The flight behaviour of a male can be tracked by up to 700 m distance with a spatial resolution of ±3 m using the harmonic radar technique. Photo: Glenn Svensson.

    Supervisors: Christer Löfstedt and Olle Anderbrant

    Funding: Swedish Council for Forestry and Agricultural research, the MISTRA foundation and the Knut and Alice Wallenberg foundation

    References:

    Ryne, C., Svensson, G. P. & Löfstedt, C. 2001. Small-scale mating disruption experiments on Plodia interpunctella: effect of pheromone blends, doses and population densities. Journal of Chemical Ecology 27:2109-2124.

    Svensson, G. P., Ryne, C. & Löfstedt, C. Heritability of sex pheromone composition and the potential for resistance evolution to pheromone-based mating disruption in the Indian meal moth, Plodia interpunctella.Journal of Chemical Ecology (submitted).

    Svensson, G. P., Valeur, P. G., Reynolds, D. R., Smith, A. D., Riley, J. R., Baker, T. C., Poppy, G. M. & Löfstedt, C. Mating diruption in Agrotis segetummonitored by harmonic radar. Entomologia Experimentalis et Applicata (in press).

    Svensson, G. P., Skals, N. & Löfstedt, C. Disuption of the odour-mediated mating behaviour of Plodia interpunctellaHübner (Lepidoptera: Pyralidae). Manuscript.

    Back to Ongoing projects

    Glenn ongoing project 2008: Yucca moths   Pheromone group ongoing projects 

    


    

This page was created 98-11-13. Updated 02-02-01.

    
Glenn Svensson, Dept. of Ecology, Lund University, SE-223 62 LUND, Sweden.    Webmaster