Search Results (8)

Cocoa (Theobroma cacao L.) relies on insect pollination for fruit production, making it essential to understand the pollinators involved. This study aimed to identify the insects associated with cocoa pollination and their relationship with effective natural pollination in a cocoa agroforestry system in Yopal, Colombia. Indirect (wood traps) and direct (manual aspiration in flowers) methods were used to capture pollinators. The number of captured insects was correlated with the percentage of pollinated, fertilized, aborted, and transitioning flowers using Pearson’s correlation coefficient. Additionally, the natural transfer of pollen was assessed by evaluating the coverage of near-opening flowers and staining pollen grains on the stigma under natural conditions. This study identified Diptera from the Ceratopogonidae family, specifically the genera Forcipomyia and Dasyhelea, as key pollinators. The findings highlight the presence of these pollinators in the Yopal cocoa agroforestry system and suggest the need for further pollinator capture and identification efforts on local farms. A positive correlation was found between the number of pollinating insects and the percentage of fertilized flowers, emphasizing the crucial role of these insects in cocoa pollination and the importance of promoting their presence to optimize fruit production. Full article

Yunnan province in China shares its borders with three neighboring countries: Myanmar, Vietnam, and Laos. The region is characterized by a diverse climate and is known to be a suitable habitat for various arthropods, including midges which are notorious for transmitting diseases which pose significant health burdens affecting both human and animal health. A total of 431,100 midges were collected from 15 different locations in the border region of Yunnan province from 2015 to 2020. These midges were divided into 37 groups according to the collection year and sampling site. These 37 groups of midges were then homogenized to extract nucleic acid. Metatranscriptomics were used to analyze their viromes. Based on the obtained cytochrome C oxidase I gene (COI) sequences, three genera were identified, including one species of Forcipomyia, one species of Dasyhelea, and twenty-five species of Culicoides. We identified a total of 3199 viruses in five orders and 12 families, including 1305 single-stranded positive-stranded RNA viruses (+ssRNA) in two orders and seven families, 175 single-stranded negative-stranded RNA viruses (−ssRNA) in two orders and one family, and 1719 double-stranded RNA viruses in five families. Six arboviruses of economic importance were identified, namely Banna virus (BAV), Japanese encephalitis virus (JEV), Akabane virus (AKV), Bluetongue virus (BTV), Tibetan circovirus (TIBOV), and Epizootic hemorrhagic disease virus (EHDV), all of which are capable, to varying extents, of causing disease in humans and/or animals. The survey sites in this study basically covered the current distribution area of midges in Yunnan province, which helps to predict the geographic expansion of midge species. The complexity and diversity of the viral spectrum carried by midges identified in the study calls for more in-depth research, which can be utilized to monitor arthropod vectors and to predict the emergence and spread of zoonoses and animal epidemics, which is of great significance for the control of vector-borne diseases. Full article

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. Full article

This study reports the virome investigation of pollinator species and other floral visitors associated with plants from the south of Bahia: Aphis aurantii, Atrichopogon sp., Dasyhelea sp., Forcipomyia taiwana, and Trigona ventralis hoozana. Studying viruses in insects associated with economically important crops is vital to understand transmission dynamics and manage viral diseases that pose as threats for global food security. Using literature mining and public RNA next-generation sequencing data deposited in the NCBI SRA database, we identified potential vectors associated with Malvaceae plant species and characterized the microbial communities resident in these insects. Bacteria and Eukarya dominated the metagenomic analyses of all taxon groups. We also found sequences showing similarity to elements from several viral families, including Bunyavirales, Chuviridae, Iflaviridae, Narnaviridae, Orthomyxoviridae, Rhabdoviridae, Totiviridae, and Xinmoviridae. Phylogenetic analyses indicated the existence of at least 16 new viruses distributed among A. aurantii (3), Atrichopogon sp. (4), Dasyhelea sp. (3), and F. taiwana (6). No novel viruses were found for T. ventralis hoozana. For F. taiwana, the available libraries also allowed us to suggest possible vertical transmission, while for A. aurantii we followed the infection profile along the insect development. Our results highlight the importance of studying the virome of insect species associated with crop pollination, as they may play a crucial role in the transmission of viruses to economically important plants, such as those of the genus Theobroma, or they will reduce the pollination process. This information may be valuable in developing strategies to mitigate the spread of viruses and protect the global industry. Full article

Forcipomyia taiwana (Diptera: Ceratopogonidae) is a nuisance blood-sucking pest to humans in Taiwan. An F. taiwana bite causes itching and redness and usually causes serious harassment to human outdoor activity. In terms of F. taiwana control, chemical pesticides are ineffective. Therefore, other efforts are needed. Fungal mycosis in the larvae, pupae, and emerging F. taiwana adults was found during the rearing of F. taiwana. In this study, six fungal isolates were isolated from infected cadavers and subjected to molecular identification. In addition, their biocontrol potential was evaluated against different life stages of F. taiwana. Based on the pathogenicity screening, two fungal isolates, NCHU-NPUST-175 and -178, which caused higher mortality on the fourth instar larvae of F. taiwana, were selected for virulence tests against different life stages of F. taiwana larvae. The results of the phylogenetic analysis indicated that the NCHU-NPUST-175 and -178 belonged to Purpureocillium lilacinum and Fusarium verticillioides, respectively. Bioassay against different life stages of F. taiwana with different spore concentrations (5 × 10⁵ to 5 × 10⁷ conidia/mL) revealed a dose-dependent effect on larvae for both fungal isolates, while only 38% and 50% mortality was found in highest concentration (5 × 10⁷ conidia/mL) at fourth instar larvae by Pl-NCHU-NPUST-175 and Fv-NCHU-NPUST-178, respectively. Moreover, reductions in egg-hatching rate and adult emergence rate were found, when the last stage of F. taiwana was inoculated with both fungal isolates, indicating the ovicidal potential and the impact of entomopathogenic fungi on the development of F. taiwana. In conclusion, Pl-NCHU-NPUST-175 and Fv-NCHU-NPUST-178 showed larvicidal activity, ovicidal activity, and impact on adult emergence on F. taiwana. Full article

Forcipomyia taiwana, a bloodsucking midge that is one of the most irritating biting pests in Taiwan, has raised widespread public concern. However, we have little information about the extent to which landscape factors affect their potential habitats. As a result, landscape professionals do not have enough information to implement preventive strategies to control midges. The purpose of this study is to investigate the relationship between landscaping and algae growth for larval breeding sites of Forcipomyia taiwana. The intent is to determine the environmental strategies that make the planned landscape unsuitable for midges to breed. GIS based on data collected from 16 constructed landscape sites (317,187 m² in total) was utilized to spatially examine the relationship between the occurrence of the algae for midge breeding sites and the ground surface types and planting characteristics in each landscape. The results revealed that the potential midge habitats can be controlled through careful selection of the ground surface, the improvement of the site drainage, and choosing plants with the appropriate characteristics. Apart from choosing the appropriate type of paving surface, the integrity of the paving installation and the coverage of the ecological surface also influence prevention efficacy. Full article

This study aims to develop nanofibrous membranes where Eucalyptus globules oil (EGO) is wrapped in polyvinyl alcohol (PVA). The EGO-based nanofibrous membranes are then evaluated for the protection against Forcipomyia taiwana (F. taiwana). In the first stage, the PVA solutions are formulated with different concentrations and are measured for viscosity and electrical conductivity. In the next stage, PVA solution and EGO are blended at different ratios and electrospun into PVA/EGO nanofibrous membranes (i.e., EGO-based repellent). In this study, a PVA concentration of 14 wt% has a positive influence on fiber formation. Furthermore, the finest nanofibers of 291 nm are presented when the voltage is 15 kV. The repellent efficacy can reach 80% in a 60-min release when the repellent is composed of a PVA/oil ratio of 90/10. To sum up, the nanofibrous membranes of essential oil exhibit good repellent efficacy against F. taiwana and significant slow-release effect, instead of adversely affecting the cell viability. Full article

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. Full article