Adaptive divergence in Ostrinia furnacalis: Diet-based fitness specification across wild, domestic and hybrid populations

Abstract

The adaptability of agricultural pests to varied environments is a critical factor in their ability to cause significant damage, making it a major challenge for effective crop management. While the adaptability of Asian corn borer (Ostrinia furnacalis) (Lepidoptera: Crambidae) is well-documented, the extent to which different populations diverge in fitness when reared on natural versus artificial diets remains poorly understood. This study addresses this gap by assessing the fitness and adaptive divergence of three O. furnacalis populations i.e., field, laboratory, and hybrid (field × laboratory), when reared on maize and artificial diets, using age-stage, two-sex life table theory. Significant differences in survival and demographic parameters were observed among the populations. The field population exhibited 32.5 % faster growth on maize, with a shorter mean generation time (T) compared to the artificial diet. In contrast, the laboratory population grew (T) 29.5 % faster on the artificial diet compared to maize. The hybrid population showed a slight preference for maize, with growth (T) being 3.1 % faster than on the artificial diet. Trends in intrinsic rate of increase (r), finite rate of increase (λ) and other associated parameters followed a consistent pattern, with field population thriving on maize and laboratory population better suited to the artificial diet. The hybrid population demonstrated balanced adaptability to both diets, with an overall slight tendency of better performing on maize. This study highlights the importance of diet-specific adaptation in O. furnacalis and provides critical insights into the adaptive divergence for optimising laboratory rearing practices and improving pest management strategies.