Silène Lartigue PhD thesis

Phenotyping personnality traits in the wasp Trichogramma: application to biological control

Funding: French Ministry of agriculture

Supervisors: Jérôme Moreau (laboratoire Biogéosciences) & Thibaut Malausa (Institut Sophia Agrobiotech)

Beginned in september 2017



Because of its negative impact on environment and human health, the use of synthetic chemical pesticides against crop pests is questioned. In France, the Ecophyto Plan aims at reducing the use of pesticides by supporting research and innovation on alternative solutions. Biological control is part of these alternatives with high potential.

One of the current weaknesses of biological control programs is that the efficiency in the field is unpredictable. One of the most promising approaches to improve biocontrol programs is a better understanding of biocontrol agents’ behaviour in order to better manage factors impacting their efficiency in the field. There is an increasing number of studies showing that individual behaviours within a population can be highly variable and that these individual differences are consistent across time and heritable (e.g. Sih et al. 2012; Kralj-fiser and Schuett 2014; Royauté and Pruitt 2015). These behavioral differences are known as animal personality, and have never been taken into account in biological control programs. This work aims at characterising behavioral variability of trichogramma, a worldwide used biocontrol agent to control lepidopteran crop pests, in order to optimise its use in agroecosystems. The specific objectives are: (i) to develop experimental designs in order to assess personality, (ii) to estimate the heritability of personality trait in order to assess their selection potential, (iii) to describe the correlation between personality traits and other life history traits that are commonly used in strain selection programs, (iv) to characterise the correlation between personality traits measured in the lab and efficiency of trichogramma measured in the field. This thesis will attempt to provide personality phenotyping methods for biocontrol agents, which could help improve industrial biocontrol programs by improving the efficiency in the field of some macro-organisms used in biocontrol.



biocontrol, behaviour, Trichogramma