A general DDE model for terrestrial arthropods: from theory to validation guidelines under controlled conditions

Models play a fundamental role in planning strategies for ecosystem conservation or, in the case of agriculture and forestry, for pest management. For this reason, in recent years there is an increasing demand of more accurate and reliable models, possibly general enough to be adapted to multiple species, once their biology is known. Models are usually validated using field data, which are however affected by uncertainties and other problems of difficult identification, such as unexpected migrations, and which can undermine the reliability of the validation process. This study introduces a new general model which describes the biology of terrestrial arthropods based on delay differential equations. Together with the model, this paper also introduces a novel method to estimate its parameters, including the minimum development times, based on life tables data. This study also introduces a validation protocol based on growth chamber experiments at different temperatures and validated the proposed theory on the case of Drosophila suzukii. The results showed a very good agreement between the population estimated by the model and the actual populations measured in growth chambers at different temperatures (10,16, 28, 32 and 34 °C). The outcomes of this study remark the connection between life tables experiments and modelling process for terrestrial arthropods and provide a general theory and application protocol that can be further applied to other species.