What makes Drosophila suzukii such a successful invader?
An integrative analysis of its thermal ecology

Funded by ANR

Project summary

The recent invasion by the Spotted Wing Drosophila (SWD) is a major concern for the fruit sector worldwide. Temperature and thermal biology of this species are recognized as the main factors dictating the distribution, populations’ dynamics and seasonal phenology of SWD. However, major knowledge gaps remain regarding its thermal and trophic ecology, thus compromising the assessment and prediction of field population dynamics from year to year. In particular, there is a critical lack of knowledge about the thermotolerance and winter survival strategies of this invasive species, which are essential for anticipating spring population levels and dynamics. Small insects such as fruit flies certainly respond to environmental variations on much finer temporal and spatial scales than those generally considered so far in classical experimental studies and predictive models. The transfer of the macroclimate projections into the microclimates actually encountered by SWDs in nature requires the acquisition of novel ecologically relevant data with a level of resolution corresponding to the insect's scale. DroThermal is based on the idea that most of the findings from laboratory experiments are difficult to extrapolate to field situations. Current knowledge on the thermal and trophic ecology of SWD is mainly based on laboratory data that lack the appropriate resolution and ecological relevance and thus hamper the accurate assessment of the persistence of SWD populations in the wild, as well as the associated modelling efforts. Many critical variables are at play in nature but absent from classical experimental conditions: i) unlike the laboratory where conditions are constant and optimal, there is a high spatial and temporal variability of abiotic factors (e.g. temperature) in nature (subject of tasks 1 & 2). ii) there is a high diversity of host plants that varies with the seasons and thus a range of available trophic resources (including unknown winter hosts) that shape phenotypes such as thermotolerance (subject of task 3). iii) Symbionts and microbes associated with the host (e.g. Wolbachia) are much more diverse in nature than in the laboratory, and can affect host characteristics, including thermotolerance (subject of task 4). Consideration of these effects in a single integrative project will generate new knowledge on the thermal and seasonal ecology of SWD, allowing better modelling of population dynamics and seasonal phenology (subject of task 5). By considering different levels of variation across appropriate spatio-temporal scales, we plan to elucidate the thermal (and seasonal) responses and adaptations of SWD, and thus better predict population persistence and dynamics in the field. DroThermal also has the applied goal of generating data needed to develop innovative predictive models of population dynamics, which are useful for sustainable management programs against SWD. Our high-resolution integrative approach will provide a better understanding of the invasive success of this species in temperate regions and will provide new knowledge essential for the management of SWD, such as improving the timing and forecasting of control measures. More broadly, the project will provide an innovative new framework to understand the success of biological invasions that present significant eco-socio-economic issues.

Project Partners

Coordinator contact

Hervé Colinet (CR-CNRS HDR)
UMR ECOBIO CNRS 6553, Bat. 14A
Université de Rennes 1
263 AVE du Général Leclerc
CS 74205
35042 Rennes Cedex
tél : +33 (0)2 23 23 64 38
email : herve.colinet@univ-rennes1.fr

The results of DROTHERMAL project are listed :

link to the participative project "DroFramb"

Drothermal website produced by Herve COLINET and hosted by CNRS