Biological pest control in agriculture refers to the use of living organisms, called biocontrol agents (insects, mites, microorganisms), to protect agricultural crops against pests. Biological pest control is an effective practice, allowing farmers to avoid using chemical pesticides, which have negative effects on biodiversity and human health.
In specific environments, however, crop protection with biological pest control can be difficult. Dry conditions, in particular, can have negative effects on biocontrol agents, and hamper the success of biological control. Understanding the effects of drought on biocontrol agents is an important step to improve biological pest control, especially in the context of climate change.
In this thesis, I studied the effects of drought on the predatory mite Phytoseiulus persimilis, used worldwide as a biocontrol agent of the two-spotted spider mite (Tetranychus urticae), a herbivorous pest. The results of my research will contribute to the improvement of biological control of two-spotted spider mites in dry conditions.