From mites to migration: linking Spinturnix psi morphometrics to the conservation of its host, the common bent-winged bat (Miniopterus schreibersii).

Geometric morphometrics has contributed significantly to understanding ecological and evolutionary patterns by analyzing shape variation in biological structures, including species identification, population differentiation, and phenotypic plasticity of different organisms. In the context of bat ectoparasites, particularly wing mites, geometric morphometrics could present a novel approach for tracking the migratory patterns of bat hosts over time. To evaluate the morphological variation of Spinturnix psi (Kolenati, 1856) mites sampled from its typical host, Miniopterus schreibersii (Kuhl, 1817), in the three caves in eastern Serbia (Bogovinska, Sokolovica, and Sesalačka caves), we applied geometric morphometrics methods. We selected the sternal shield as the character to be analyzed and positioned 10 landmarks to describe its shape in females and 20 landmarks in males respectively. The analysis revealed statistically significant shape differences in the males, where a clear differentiation of specimens from Bogovinska cave compared to specimens from the other two localities was found, while in the females no differences were observed. Nevertheless, pairwise comparisons showed a weak but significant signal indicating differences between females from Bogovinska and Sesalačka caves. These subtle morphological variation in mites could help clarify the links between different host roosting sites, and a better understanding of the migration patterns of bats.