New biological model to manage the impact of climate warming on maize corn borers

Climate change can modify the development of insect pests and their impact on crops. The study of future impacts on maize remains relatively unexplored. Here we modeled the distribution and development of the maize borer Sesamia nonagrioides Lef. in Europe using a 25 × 25 km grid. We studied the pest potential winter survival, distribution, and phenological development at three time horizons, 2000, 2030, and 2050, using the A1B scenario of the international panel on climate change (IPCC). A new model based on the lethal dose exposure concept was developed to simulate winter survival. Two approaches for the simulation of winter survival were compared: the first using air temperature only as weather input, named AirMS; the second taking into account the fraction of larvae overwintering in the soil, therefore considering also soil temperature, named SoilAirMS. The survival model was linked to a phenological model to simulate the potential development. Results show that soil temperature is an essential input for correctly simulating S. nonagrioides distribution. The SoilAirMS approach showed the best agreement (+537 grid cells), compared to the AirMS approach (−2,039 grid cells). Nevertheless, the AirMS approach allowed identifying areas where the agronomic practice suggested for controlling S. nonagrioides should be considered ineffective. This practice consists in uprooting and exposing the stubble on the soils surface for exposing larvae to winter cold. The projections to 2030 and 2050 suggested an overall slight increase of more suitable conditions for the S. nonagrioides in almost all the areas where it develops under the baseline. In these areas, S. nonagrioides could become a new insect pest with a potential strong impact on maize. This is the first attempt to provide extensive estimates on the effects of climate change on S. nonagrioides distribution, development, and on possible management changes.