Conflicting hypotheses about the relationships among the major lineages of aculeate Hymenoptera clearly show the necessity of detailed comparative morphological studies. Using micro-computed tomography and 3D reconstructions, the skeletal musculature of the meso- and metathorax and the first and second abdominal segment in Apoidea are described. Females of Sceliphron destillatorium, Sphex (Fernaldina) lucae (both Sphecidae), and Ampulex compressa (Ampulicidae) were examined. The morphological terminology provided by the Hymenoptera Anatomy Ontology is used. Up to 42 muscles were found. The three species differ in certain numerical and structural aspects. Ampulicidae differs significantly from Sphecidae in the metathorax and the anterior abdomen. The metapleural apodeme and paracoxal ridge are weakly developed in Ampulicidae, which affect some muscular structures. Furthermore, the muscles that insert on the coxae and trochanters are broader and longer in Ampulicidae. A conspicuous characteristic of Sphecidae is the absence of the metaphragma. Overall, we identified four hitherto unrecognized muscles. Our work suggests additional investigations on structures discussed in this paper.

The sting apparatus of aculeate Hymenoptera is derived from the ovipositor and is their most prominent apomorphy. In contrast to the frequently analysed sclerites of the sting apparatus, the associated musculature has largely been neglected. In this study, we use micro-computed tomography to present a detailed description of the musculature of the sting apparatus of Ampulex compressa (Ampulicidae) and Sceliphron destillatorium (Sphecidae). We found that 12 of 15 muscles corresponding to the sting apparatus are homologous between both species examined and 13 muscles in comparison with Hymenoptera described in the literature. All muscles identified as critical for the act of stinging were found in both species. Moreover, we found the ventral tergum 8-tergum 9 muscle and the tergum 8-tergum 8 muscles in A. compressa and the second valvifer-second valvifer muscle in S. destillatorium. For the first time, we describe the ventral tergum 8-tergum 9 muscle and the second valvifer-second valvifer muscle that interconnects both body sides, in Hymenoptera.

The biogeographic dynamics affecting the Indian subcontinent, East and Southeast Asia during the Plio-Pleistocene has generated complex biodiversity patterns. We assessed the molecular biogeography of the small Indian civet (Viverricula indica) through mitogenome and cytochrome b + control region sequencing of 89 historical and modern samples to (1) establish a time-calibrated phylogeography across the species' native range and (2) test introduction scenarios to western Indian Ocean islands. Bayesian phylogenetic analyses identified 3 geographic lineages (East Asia, sister-group to Southeast Asia and the Indian subcontinent + northern Indochina) diverging 3.2-2.3 million years ago (Mya), with no clear signature of past demographic expansion. Within Southeast Asia, Balinese populations separated from the rest 2.6-1.3 Mya. Western Indian Ocean populations were assigned to the Indian subcontinent + northern Indochina lineage and had the lowest mitochondrial diversity. Approximate Bayesian computation did not distinguish between single versus multiple introduction scenarios. The early diversification of the small Indian civet was likely shaped by humid periods in the Late Pliocene-Early Pleistocene that created evergreen rainforest barriers, generating areas of intra-specific endemism in the Indian subcontinent, East, and Southeast Asia. Later, Pleistocene dispersals through drier conditions in South and Southeast Asia were likely, giving rise to the species' current natural distribution. Our molecular data supported the delineation of only 4 subspecies in V. indica, including an endemic Balinese lineage. Our study also highlighted the influence of prefirst millennium AD introductions to western Indian Ocean islands, with Indian and/or Arab traders probably introducing the species for its civet oil.