No single host is optimal: effects of fruit species on development and adult performance in Anastrepha fraterculus...

Many phytophagous insects develop within discrete and non-renewable resources, such as fruits, making host choice a critical determinant of offspring performance. In tephritid fruit flies, host fruit quality can strongly influence development, survival, and adult reproductive traits, yet no single host may optimize all life-history parameters. Here, we evaluated the effects of six host fruit species-native and exotic-on larval development and adult performance of the South American fruit fly Anastrepha fraterculus, a highly polyphagous and economically important pest. Under controlled laboratory conditions, we quantified developmental time, pupal survival, adult size, ovary development, male sexual maturation, and starvation resistance. Host species significantly affected all measured traits, revealing pronounced trade-offs among life-history parameters. Guava, a native host, supported the fastest larval development but produced smaller adults with reduced ovary development and lower starvation resistance. Feijoa, another native host, behaved similarly to guava, although pupal mortality was higher and sexual maturation faster than in guava. Peach and plum consistently yielded larger adults with well-developed ovaries and higher overall performance, whereas loquat generally resulted in poorer outcomes across several traits. Grapefruit induced prolonged larval development but promoted early male sexual maturation. Heatmap and PCA analyses confirmed that no single host maximized performance across all traits. These results challenge the assumption that native hosts necessarily confer superior fitness and suggest a decoupling between host use in nature and host suitability under laboratory conditions. Our findings highlight the complexity of host-insect interactions in polyphagous fruit flies and suggest that different host species may be selectively advantageous depending on ecological context and demographic needs. Understanding these trade-offs is essential for predicting population dynamics and improving integrated management strategies for A. fraterculus.