The Rhiniinae (Diptera: Calliphoridae), a recently reclassified subfamily of blowflies, comprise approximately 400 species across 30 to 39 genera, which occupy diverse ecological associations, including flower visitation and specialized associations with social insects, yet their phylogenetic relationships remain poorly established due to lack of molecular data. We sequenced and characterized the complete mitochondrial genome of six representative Rhiniinae species, with which the phylogenetic analyses were conducted. The monophyly of Rhiniinae was robustly supported and the internal relationships were clarified. Rhiniini and Cosminini were both recovered as well-supported monophyletic tribes using comprehensive mitogenomic evidence for the first time. In contrast to the purifying selection prevailing in most protein-coding genes, the COII gene showed consistent signatures of positive selection, potentially linked to the functional optimization of cytochrome c oxidase. Overall, this study provides foundational mitogenomic data and a robust phylogenetic framework, offering valuable resources for future research on mitochondrial evolution and systematics within this ecologically intriguing lineage.

Cobboldia elephantis (Oestridae: Gasterophilinae) is an obligate parasite of the alimentary tract of the Asian elephant, causing gastric myiasis. Current knowledge of its first instar larval morphology has been limited to observations under light microscopy, significantly constraining our understanding of morphological evolution within the genus Cobboldia and the broader subfamily Gasterophilinae. In this study, we provided ultrastructural and three-dimensional characterizations of C. elephantis using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) based on newly hatched first instar larvae. Features of the first instar larva of C. elephantis, which are either unique or shared with C. loxodontis Brauer, 1896, include (i) three pairs of mouthhooks, (ii) posterior spiracles bearing peristigmatic tufts, (iii) anal division with two spine-clusters and a row of elongated spines, and (iv) a planed, button-like sensilla and a sensillum placodeum. We also compared the first instar larval morphology of C. elephantis with that of Cobboldia loxodontis, Gyrostigma rhinocerontis (Owen, 1830), Gasterophilus pecorum (Fabricius, 1794), Portschinskia magnifica Pleske, 1926, and Oestrus ovis Linnaeus, 1758. Species of Gasterophilinae share several unique features of the first instar larva, including (i) an anal division composed of three subdivisions, (ii) spiracular slits on the posterior spiracles, and (iii) conserved positioning of thoracic sensilla. These findings fill a key gap in our knowledge of C. elephantis larval morphology and suggest that these distinctive structures play a role in adaptation to its parasitic lifestyle.

Hypoderma diana Brauer, 1858, poses a significant threat to species of deer, yet records of this species in China remain fragmented and lack comprehensive documentation. Following high mortality in wapiti populations in Inner Mongolia during 2023–2024, surveys were conducted in the Gaogesitai Hanwula Nature Reserve in March 2025. Species identity was established through rigorous morphological analysis of third-instar larvae and an emerged adult female using light and scanning electron microscopy, supplemented by a 689 bp COI fragment. Results confirmed H. diana as the causative agent, with larvae localized along the host’s vertebral column. Comparative SEM analysis of the antennomaxillary sensory complex in H. diana, H. bovis (Linnaeus, 1758), and H. lineatum (Villers, 1789) revealed undifferentiated, volcano-like warts, contrasting sharply with the highly differentiated antennae and sensilla of Oestrus ovis Linnaeus, 1758. This study represents an inaugural record of H. diana in the Chifeng region and provides the first atlas of diagnostic features for both third-instar larvae and adults. These findings document H. diana as a critical agent of myiasis in the Manchurian wapiti, refining its known epidemiological profile in China and establishing an essential morphological reference for future wildlife health surveillance.