1In the Ecuadorian Andes, an invasive insect, the Guatemalan potato moth, has been wreaking havoc in potato fields for years, ruining up to 100% of crops. IRD began to explore this scourge in the early 2000s, showing that the development cycle of this species, like that of most insects, was closely correlated with temperature. This finding prompted researchers to look at the effect of the thermal heterogeneity of the environment on the behaviour of these pests. They became interested in measuring this heterogeneity, not on the scale of the planet, continent, region or field but on the scale of the insect, i.e. the centimetre.

Thermal landscape based on images from a drone.

2This is why, in 2012, researchers equipped a drone with a thermal camera and precisely configured its flight route and altitude using an autopilot and GPS coordinates. This innovation allowed them to record changes in temperature on the surface of plant leaves. They showed that, within a 1.5 metre radius, insects can find a range of higher or lower temperatures within a 20°C range in relation to air temperature, thereby allowing them to adapt to ambient temperature fluctuations. This surprise discovery put the possible impact of climate change in perspective, at least for these pests.

Drone flying over a field, Ecuador.

3This research led to the development of a digital tool kit, making it easier to monitor the health of fields via drones equipped with a thermal camera. The temperature of leaves damaged by pests changes, which enables their detection and paves the way for targeted action. In addition, an ongoing analysis of changes in temperature based on the position of plants could help design field architectures that are less conducive to moth invasions.