Population dynamics -and simulation of earwings in orchards: density dependence in a population of generalist predators.

Earwigs, Forficula auricularia (L.) (Dermaptera, Forficulidae), are very important predators in fruit orchards. They are capable of suppressing outbreaks of pest species like pear psyllid and different aphid species, in apple and pear orchards. Earwigs could play an important role in integrated fruit orchards en could be an essential key factor in organic fruit growing. However, earwig populations are very unstable with large interannual variations in population size. Therefore, their practical use in control strategies stays very limited.To find solutions for this problem we are building a population model which will allow us to analyse the population with sensitivity analysis, so that critical periods in the life-cycle could be identified as targets for interventionbs. This should result into an optimal orchard management were abiotic and biotic factors and the impact of human actions on the earwig population are taken into account. The existing biological information needed to create such a model is not sufficient, especially where it concerns interactions with other species. Using a combination of field -and lab experiments, we will collect information about the model parameters for such interactions. In this project we will focus mainly on density dependent factors, like parasitism (by tachinids), predation, intra- and interspecific competition.

Keywords:ECOLOGICAL MODELLING, ANIMAL ECOLOGY, FARMING SYSTEMS, INSECTA, POPULATION DYNAMICS, POPULATION ECOLOGY, PREDATION

Disciplines:Animal biology, Ecology, Plant biology, Environmental science and management, Other environmental sciences, Agricultural plant production, Horticultural production