European Corn Borer life stage model: Regional estimates of pest development and spatial distribution under present and future climate

Predicting the potential distribution of agricultural pests, both indigenous and introduced, plays a key role in determining the impact of global change on agricultural, horticultural and forestry ecosystems. This study investigates changes in the climatic niche of one of the most important agricultural pests, the European Corn Borer (Ostrinia nubilalis, Hubner), using the multi-generational phenology model ECAMON. The model enables us to predict the development of the European Corn Borer (ECB), to estimate the risk of its establishing a permanent population, and to give an indication of climate-related stress factors affecting the species. The evaluation of ECAMON demonstrated that it provides accurate predictions of the onset and duration of the key phenological stages over a broad range of sites. It explains over 70% of the variation in the timing of key developmental stages based only on daily weather data. ECAMON simulations correctly predicted the presence/absence of the ECB over the study region during the 1961–1990 reference period. It also helped to explain the sudden increase in the maize infestation over the territory of the Czech Republic during the unusually warm period of 1991–2000. The ECAMON results demonstrated that the effect of climate will be significant and complex. According to our estimates, the extent of the climate niche will expand within the next 20–30 years to cover almost the entire area suitable for agriculture by 2040–2075. The establishment of a bivoltine population is not imminent within the next decade, but it is likely to take place during the period of 2025–2050. The timing and extent of these changes will be affected not only by changes in the means of key meteorological parameters, but also in their variability. These shifts will be clearly accompanied by an earlier onset of key developmental stages of the pest. The study demonstrated that the level of uncertainty caused both by emission scenarios and by differences in global circulation models (GCMs) are of the same order of magnitude. Thus, only the combination of a wide range of emission scenarios and GCMs can provide insight into the potential effect of climate change on any particular species. Under future climate conditions, grain maize is expected to partly replace traditional cereals (e.g. winter wheat, rye, etc.); thus the establishment of a national or international monitoring scheme is desirable, and an ECAMON-like tool might serve as the basic modeling platform for such an effort.