A dynamic model to simulate the development of insecticide resistance

In this article, we described a dynamic model to simulate the development of insecticide resistance. The variables as insecticide use dosage, timing and frequency of insecticide uses, genetic mutagenicity of insect individuals, insecticide-resistant individuals' fitness, etc., were included in the model. Sensitivity analysis of the model indicated that the lower the fitness of the insecticide-resistant individuals is, the slower the increase of insecticide resistance will be. Simulation of the model showed that the greater the insect individuals' mutagenicity is, the more quickly the insecticide resistance will rise. The greater the insecticide use dosage is, the more quickly the insecticide resistance will increase. The higher the frequency of insecticide uses is, the greater the insecticide resistance will increase. The results showed that the insecticide dosage is more important than usage frequency in determining the development of insecticide resistance, which highlights the importance of joint use of reducing insecticide dosage and adopting IPM technologies. The model can be used to not only the dynamic simuation of development of insecticide resistance but also the assessment of IPM technologies in reducing insecticide resistance. For example, with a set of specific parametrical values, the simulation of the model demonstated that insecticide resistance will reduce 83.74% when the insecticide dosage is reduced from 180 to 20 by jointly using IPM technologies. Full codes of Matlab, R and BASIC programs for the model were given.