Predicting Potential Range Shifts and Molecular Approaches in Four Diolcogaster Ashmead Species (Hymenoptera:...

Diolcogaster Ashmead is a genus of Microgastrinae (Hymenoptera: Braconidae) wasps with patchy distribution ranges. This study assessed and predicted the geographical distribution of four Diolcogaster species worldwide using field data and species distribution models (SDMs). The models projected the contemporary and future distributional ranges for the twenty-first century. Nine informative environmental variables were employed to model the ecological niche with the MaxEnt model. Furthermore, a maximum likelihood phylogenetic estimation tree was reconstructed using IQ-TREE, with the underlying data being COI-based. Finally, PopART was used to perform a haplotype network analysis to assess the haplotype diversity and evolutionary distances of the four Diolcogaster species. The MaxEnt models showed excellent predictive performance (AUC > 0.9, TSS > 0.8) for all species. Diolcogaster claritibia occupied the widest and most suitable niches globally, followed by D. mayae, D. alvearia, and D. spreta. Molecular analyses supported the predicted models, indicating that D. claritibia's adaptation to various habitats. Two environmental variables significantly influenced the distribution patterns of the four species. Diolcogaster claritibia and D. mayae are ecologically versatile, adapting to diverse habitats, elevations, and environmental conditions. Thus, their distribution ranges may extend beyond the previously documented limits. The four Diolcogaster species are currently predominantly found in temperate regions, preferring cooler climates. The model predicts that these species will expand into subtropical regions. This study offers a foundational theoretical framework for the practical rearing and strategic use of the wasps, as all Microgastrinae members are important biocontrol agents of caterpillar larvae.