A novel modelling approach to describe an insect life cycle vis-à-vis plant protection: description and application in the case study of Tuta absoluta

Abstract

The Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), commonly known as the tomato leaf miner, is arousing interest throughout the scientific community because of its aggressiveness against Lycopersicon spp., Capsicum spp. and Solanum spp. Significant economic losses surrounding the tomato plant have been reported in different parts of the world and these are, above all, the result of the immense capacity of the tomato leaf miner to reproduce within its life cycle, which spans an average of 30 days. The aim of this paper is the demonstration of a novel mathematical model capable to describe ectotherms life cycle, and to test it in the case of T. absoluta. A mathematical description can help farmers and stakeholders to forecast when the stages at which the insect is most susceptible to control strategies, will be reached. This will allow timely planning for the performance of the most efficient and environmentally friendly control strategy. The model is based on a first order partial differential equation, which can describe the density of population in function of the time t, and physiological age x, and which is driven by the environmental parameters and fundamental conditions for poikilothermic organisms. The result is a simulation of the life cycle, which depicts that the development of the insect is largely due to daily average temperature. This study is strengthened by double validation with semi-field data collected in an experimental greenhouse.