Life stage and resistance effects in modelling phosphine fumigation of <i>Rhyzopertha dominica</i> (F.)

  • J. Thorne School of Mathematical Sciences, Queensland University of Technology QLD. Email: j1.thorne@student.qut.edu.au; Cooperative Research Centre for National Plant Biosecurity, LPO Box 5012, Bruce, ACT 2617
  • G. Fulford School of Mathematical Sciences, Queensland University of Technology QLD.; Cooperative Research Centre for National Plant Biosecurity, LPO Box 5012, Bruce, ACT 2617
  • A. Ridley Agri-Science Queensland, DEEDI, 80 Meiers Road, Indooroopilly, QLD; Cooperative Research Centre for National Plant Biosecurity, LPO Box 5012, Bruce, ACT 2617
  • D. Schlipalius Agri-Science Queensland, DEEDI, 80 Meiers Road, Indooroopilly, QLD; Cooperative Research Centre for National Plant Biosecurity, LPO Box 5012, Bruce, ACT 2617
  • P. Collins Agri-Science Queensland, DEEDI, 80 Meiers Road, Indooroopilly, QLD; Cooperative Research Centre for National Plant Biosecurity, LPO Box 5012, Bruce, ACT 2617

Abstract

Resistance to phosphine in insect pests of stored grain is a serious problem and there is a world-wide need for the development of sustainable resistance management strategies. Here we introduce results from a new mathematical model of resistance development that includes all life stages, rates of oviposition, natural mortality and mortality under fumigation in relation to resistant genotype. The example we discuss is phosphine resistance in the lesser grain borer, Rhyzopertha dominica where resistance is known to be controlled by two major genes that are close to recessive in expression, so that resistance is not fully expressed unless both resistant genes are present and homozygous. An example of a scenario where this model could be used concerns the repeat application of phosphine in a situation where control of all life stages has not been achieved. We determined a critical interval within which a second fumigation must occur to stop a rapidly recovering population of resistant genotypes. Such scenarios can be readily investigated using this approach to provide the grain industry with resistance management options and strategies.

Keywords: Rhyzopertha dominica, Population dynamics, Stored wheat, Phosphine fumigant, Low concentration

Veröffentlicht
2010-09-02
Rubrik
Section: Fumigation, Modified Atmospheres and Hermetic Storage