Forcipomyia (Lasiohelea) taiwana, a small bloodsucking midge, thrives in moderately moist habitats and is commonly found in grassy and bushy areas at an elevation below 250 m. This species exhibits a diurnal biting pattern and shows a marked preference for human blood. Although not known to transmit arthropod-borne diseases, the bites of F. taiwana can induce severe allergic reactions in some individuals. As a significant nuisance in Taiwan, affecting both daily life and the tourism industry, comprehensive studies on its population genetics across different geographical regions remain scarce. The central mountain ranges in Taiwan, comprising more than two hundred peaks above 3000 m in elevation, extend from the north to the south of the island, creating distinct eastern and western geographical divisions. This study utilizes microsatellite markers to explore the genetic differentiation of F. taiwana populations located in the eastern and western regions of the mountain ranges. Our findings reveal substantial genetic differentiation among populations inhabiting Taiwan\'s western region compared to those in the eastern region. This indicates that the topographical barriers presented by the mountain ranges significantly restrict gene flow, particularly given the species\' limited active flight ability and habitat preferences. Although passive dispersal mechanisms, like wind or human activity, could contribute, this study concludes that the gene flow of F. taiwana between the western and eastern regions is primarily influenced by topographical constraints.

Forcipomyia taiwana is an irritating hematophagous midge that preferentially attacks humans and affects leisure industries in Taiwan. Understanding the female reproductive biology of such pests would facilitate the development of pest control strategies. However, knowledge about oogenesis in the genus Forcipomyia is unavailable. Accordingly, we examined the ovariole structure and features of oogenesis in terms of the oocyte and the nurse cell. After being blood-fed, we observed a high degree of gonotrophic harmony-the synchronization of developing follicles. The follicle of the F. taiwana has only one nurse cell connected to the oocyte, which is distinct among hematophagous midges. In the nurse cell, we identified the perinuclear localization of the germline marker, Vasa. The Vasa localization is reminiscent of the nuclear envelope-associated nuage observed by electron microscopy. To determine whether F. taiwana Vasa (FtVasa) is an authentic nuage component, we produced transgenic flies expressing FtVasa in the female germline and proved that FtVasa was able to be localized to Drosophila nuage. By characterizing the oogenesis and Vasa expression in the germline cells of F. taiwana, this study extends knowledge about the female reproductive biology of hematophagous midges.

The dorsolateral setae of Forcipomyia nigra have been investigated. They are mechanoreceptors, sensilla trichoidea, innerved by a single neuron. The tubular body is located at the base of the hair shaft. Although the fine structure of the dorsolateral setae is similar to dorsal setae that perform a double function: secretion of a hygroscopic viscous substance through the pores and mechanoreception dorsolateral setae, they do not secrete any fluid. In both types of setae, trichogen cells (hair forming cells) produce the hair shafts and thereafter do not retract from the cavity of the setae. They contain a large polyploid nucleus and expanded bundles of microtubules. In dorsolateral mechanoreceptors, the microtubules form a network around the nucleus of the trichogen cell and are especially numerous in the cytoplasm invading the interior of the seta, which is evidenced by immunofluorescence light microscopy. No tormogen cell, responsible for the production of the setal socket, was found. Our observations indicate that the dorsolateral setae are solely mechanoreceptors but their trichogen cells reveal some glandular activity.

Pupae of Forcipomyia nigra biting midges bear double rows of dorsal and lateral spines. Their arrangement corresponds to the distribution of larval mechanosensory setae. They are serrated simple cuticular structures with tubercles but, in contrast to larval secretory mechanoreceptors, they are not innervated and do not exhibit any pores. The ultrastructure of abdominal spines varies among different pupal stages. They are produced by epidermal cells which fill the interior of the spine. In the youngest pupae epidermal cells are tightly packed and adhere to the cuticle. Then, the cells withdraw from the spinal cavity and the beginning of autophagy is observed. The last stage represents abdominal spines without any cellular material and then apoptosis probably proceeds in the withdrawn epidermal cells. Since the pupal spines occupied the same region of the segment as the larval setae, we consider that the same genes are responsible for their formation as for the formation of epidermal cells but that their mechanosensory and secretory function is no longer needed.

DNA barcoding in Ceratopogonidae has been restricted to interpreting the medically and veterinary important members of Culicoides Latreille. Here the technique is utilised, together with morphological study, to interpret all members of the family in a select area. Limited sampling from the county of Finnmark in northernmost Norway indicated the presence of 54 species, including 14 likely new to science, 16 new to Norway, and one new to Europe. No species were previously recorded from this county. Only 93 species were known for all of Norway before this survey, indicating how poorly studied the group is. We evaluate and discuss morphological characters commonly used in identification of biting midges and relate species diagnoses to released DNA barcode data from 223 specimens forming 58 barcode clusters in our dataset. DNA barcodes and morphology were congruent for all species, except in three morphological species where highly divergent barcode clusters indicate the possible presence of cryptic species.