Modelling the movement and survival of the root-feeding clover weevil, Sitona lepidus, in the root-zone of white clover

Xiaoxian Zhang, Scott N. Johnson, Peter J. Gregory, John W. Crawford, Iain M. Young, Philip J. Murray, Steve C. Jarvis

Research output: Contribution to journalArticle

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Abstract

White clover (Trifolium repens) is an important pasture legume but is often difficult to sustain in a mixed sward because, among other things, of the damage to roots caused by the soil-dwelling larval stages of S. lepidus. Locating the root nodules on the white clover roots is crucial for the survival of the newly hatched larvae. This paper presents a numerical model to simulate the movement of newly hatched S. lepidus larvae towards the root nodules, guided by a chemical signal released by the nodules. The model is based on the diffusion–chemotaxis equation. Experimental observations showed that the average speed of the larvae remained approximately constant, so the diffusion–chemotaxis model was modified so that the larvae respond only to the gradient direction of the chemical signal but not its magnitude. An individual-based lattice Boltzmann method was used to simulate the movement of individual larvae, and the parameters required for the model were estimated from the measurement of larval movement towards nodules in soil scanned using X-ray microtomography. The model was used to investigate the effects of nodule density, the rate of release of chemical signal, the sensitivity of the larvae to the signal, and the random foraging of the larvae on the movement and subsequent survival of the larvae. The simulations showed that the most significant factors for larval survival were nodule density and the sensitivity of the larvae to the signal. The dependence of larval survival rate on nodule density was well fitted by the Michealis–Menten kinetics.
Original languageEnglish
Pages (from-to)133-146
Number of pages14
JournalEcological Modelling
Volume190
Issue number1-2
DOIs
StatePublished - Jan 2006

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larvae
Trifolium repens
Sitona lepidus
chemotaxis
root nodules
soil
micro-computed tomography
forage legumes
sward
diffusivity
Curculionidae
rhizosphere
survival rate
foraging
kinetics
methodology

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Zhang, X., Johnson, S. N., Gregory, P. J., Crawford, J. W., Young, I. M., Murray, P. J., & Jarvis, S. C. (2006). Modelling the movement and survival of the root-feeding clover weevil, Sitona lepidus, in the root-zone of white clover. Ecological Modelling, 190(1-2), 133-146. DOI: 10.1016/j.ecolmodel.2005.01.063

Zhang, Xiaoxian; Johnson, Scott N.; Gregory, Peter J.; Crawford, John W.; Young, Iain M.; Murray, Philip J.; Jarvis, Steve C. / Modelling the movement and survival of the root-feeding clover weevil, Sitona lepidus, in the root-zone of white clover.

In: Ecological Modelling, Vol. 190, No. 1-2, 01.2006, p. 133-146.

Research output: Contribution to journalArticle

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abstract = "White clover (Trifolium repens) is an important pasture legume but is often difficult to sustain in a mixed sward because, among other things, of the damage to roots caused by the soil-dwelling larval stages of S. lepidus. Locating the root nodules on the white clover roots is crucial for the survival of the newly hatched larvae. This paper presents a numerical model to simulate the movement of newly hatched S. lepidus larvae towards the root nodules, guided by a chemical signal released by the nodules. The model is based on the diffusion–chemotaxis equation. Experimental observations showed that the average speed of the larvae remained approximately constant, so the diffusion–chemotaxis model was modified so that the larvae respond only to the gradient direction of the chemical signal but not its magnitude. An individual-based lattice Boltzmann method was used to simulate the movement of individual larvae, and the parameters required for the model were estimated from the measurement of larval movement towards nodules in soil scanned using X-ray microtomography. The model was used to investigate the effects of nodule density, the rate of release of chemical signal, the sensitivity of the larvae to the signal, and the random foraging of the larvae on the movement and subsequent survival of the larvae. The simulations showed that the most significant factors for larval survival were nodule density and the sensitivity of the larvae to the signal. The dependence of larval survival rate on nodule density was well fitted by the Michealis–Menten kinetics.",
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Zhang, X, Johnson, SN, Gregory, PJ, Crawford, JW, Young, IM, Murray, PJ & Jarvis, SC 2006, 'Modelling the movement and survival of the root-feeding clover weevil, Sitona lepidus, in the root-zone of white clover' Ecological Modelling, vol 190, no. 1-2, pp. 133-146. DOI: 10.1016/j.ecolmodel.2005.01.063

Modelling the movement and survival of the root-feeding clover weevil, Sitona lepidus, in the root-zone of white clover. / Zhang, Xiaoxian; Johnson, Scott N.; Gregory, Peter J.; Crawford, John W.; Young, Iain M.; Murray, Philip J.; Jarvis, Steve C.

In: Ecological Modelling, Vol. 190, No. 1-2, 01.2006, p. 133-146.

Research output: Contribution to journalArticle

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AU - Zhang,Xiaoxian

AU - Johnson,Scott N.

AU - Gregory,Peter J.

AU - Crawford,John W.

AU - Young,Iain M.

AU - Murray,Philip J.

AU - Jarvis,Steve C.

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AB - White clover (Trifolium repens) is an important pasture legume but is often difficult to sustain in a mixed sward because, among other things, of the damage to roots caused by the soil-dwelling larval stages of S. lepidus. Locating the root nodules on the white clover roots is crucial for the survival of the newly hatched larvae. This paper presents a numerical model to simulate the movement of newly hatched S. lepidus larvae towards the root nodules, guided by a chemical signal released by the nodules. The model is based on the diffusion–chemotaxis equation. Experimental observations showed that the average speed of the larvae remained approximately constant, so the diffusion–chemotaxis model was modified so that the larvae respond only to the gradient direction of the chemical signal but not its magnitude. An individual-based lattice Boltzmann method was used to simulate the movement of individual larvae, and the parameters required for the model were estimated from the measurement of larval movement towards nodules in soil scanned using X-ray microtomography. The model was used to investigate the effects of nodule density, the rate of release of chemical signal, the sensitivity of the larvae to the signal, and the random foraging of the larvae on the movement and subsequent survival of the larvae. The simulations showed that the most significant factors for larval survival were nodule density and the sensitivity of the larvae to the signal. The dependence of larval survival rate on nodule density was well fitted by the Michealis–Menten kinetics.

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M3 - Article

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JO - Ecological Modelling

T2 - Ecological Modelling

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ER -

Zhang X, Johnson SN, Gregory PJ, Crawford JW, Young IM, Murray PJ et al. Modelling the movement and survival of the root-feeding clover weevil, Sitona lepidus, in the root-zone of white clover. Ecological Modelling. 2006 Jan;190(1-2):133-146. Available from, DOI: 10.1016/j.ecolmodel.2005.01.063