Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

FP7

BIOMODICS Report Summary

Project reference: 612566
Funded under: FP7-PEOPLE

Periodic Report Summary 1 - BIOMODICS (Biological Control as a model system to investigate the factors affecting the establishment and dynamics of introduced populations)

Classical biological control of crop pests consists in the importation of natural enemies to regulate the populations of an exotic target pest invading a territory. It is by its very nature an international R&D activity, involving researchers in the native region of the pest and researchers in the countries invaded by the pest.
Classical biological control is also a particularly well-suited system to study the factors (demographic, genetic, and environmental) influencing the dynamics of animal populations establishing in a new environment, which correspond to a timely research question in evolutionary biology. Targeting this question requires experimental approaches, in which factors can be manipulated and isolated. Classical biological control is a particularly appropriate model system to develop such approaches because it offers the exceptional opportunity to manipulate the characteristics of introduced natural enemy populations and their conditions of introductions, be it in the laboratory (when imported from the native region of the exotic pest) or in the field (when natural enemies are released in the territory invaded by the pest).
The project Biomodics joins the forces of five research institutions from France, Spain, Chile, New Zealand and South Africa, with the aim to carry out several classical biological control programmes benefitting from international collaborations, and taking profit of these programmes to address the evolutionary ecology topic described above.
The classical biological control programmes considered target three pests of economic relevance both in the European Union and the partner countries: the codling moth Cydia pomonella (Lepidoptera: Tortricidae) and the invasive mealybugs Delottococcus aberiae and Planococcus ficus (Hemiptera: Pseudococcidae).
In 2014 and 2015, the research teams have successfully started the biological programmes. First, they characterized the biological material collected in the native regions of the pests and natural enemies. Characterization methods included morphological examination and molecular analyses (Beltrà et al. 2015. PloS One 10), notably with microsatellite markers specifically developed for the project (Retamal et al., submitted). Then, the teams studied in the laboratory the biological characteristics of the natural enemies (e.g. phenotypic traits and host ranges) considered for biocontrol releases against the pests in France and Spain.
First experiments using the biological control programmes to test hypotheses on the factors affecting the establishment of introduced populations were carried out. The experiments took place in laboratory conditions, to understand if inbreeding depression affected the establishment capacity of the parasitoid micro-wasp Mastrus ridens (Hymenoptera: Ichneumonidae). Over three generations, inbred populations displayed higher rates of establishment failure. These experiments, and complementary molecular analyses with microsatellite markers, suggest that this result was the consequence of a mechanism known in Hymenoptera as “Single-Locus Complementary Sex-Determinism” (sl-CSD). In species with sl-CSD, the sex of individuals is determined by the CSD gene. When a diploid individual displays two different versions of the gene, it develops as a female. When both chromosomes of a diploid individual display a same version of the CSD gene, the individual develops as a male with lower fitness, which is detrimental to the whole population. In inbred populations, in which genetic diversity is low, the probability for individuals to carry a single version of the CSD gene is higher, which generates higher rates of unfit males and can affect establishment capacity.
Over the second part of the Biomodics project, the teams will further develop the biocontrol programmes, ultimately leading to the introduction of natural enemies if efficiency and safety criteria of the programmes are met. In parallel, they will perform additional experiments testing demographic and genetic factors affecting the establishment dynamics of the natural enemy populations.

Contact

MODESTE, Sylvie (in charge of partnership agreements)
Tel.: +33 4 32 72 20 67
E-mail

Subjects

Life Sciences
Record Number: 183811 / Last updated on: 2016-06-14
Information source: SESAM