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Invasive alien species often affect native ecosystems worldwide. In Japan, the channel catfish Ictalurus punctatus is an invasive species in rivers. However, information regarding its feeding habits in rivers around dam reservoirs is still scarce. Thus, in this study, we assessed the feeding habits of I. punctatus collected from the Nunome River, a secondary tributary of the Yodo River, downstream of the Nunome Dam reservoir. Standard length and weight of the collected individuals were measured, and their stomach contents were analyzed under a stereomicroscope to identify prey species. Moreover, stable isotope analysis was conducted to determine their trophic niche. Overall, I. punctatus was shown to feed on a variety of food resources derived from the riparian forest and river ecosystem; in particular, algae represented 78.8% of its stomach contents. However, stable isotope analysis suggested that I. punctatus depended on benthic insects and fish to ensure adequate body composition, whereas algae were not assimilated by I. punctatus. Among benthic insects, I. punctatus relied on trichopteran larvae such as Macrostemum radiatum, which appears downstream of the dam reservoir and utilizes plankton algae from the dam. In conclusion, these findings provide additional clues for a better understanding of I. punctatus feeding activity and its relationship with its surrounding ecosystem. [ABSTRACT FROM AUTHOR]

A surveillance of Culicoides biting midges with light suction traps was conducted in the northern region of Honshu, main island of Japan, during the summers and autumns of 2009 and 2010. A total of 106 trap collections across 37 cattle farms were investigated for the structure and distribution of Culicoides species. Forty-thousand and one hundred forty-nine specimens of Culicoides biting midges were identified at the species level, and ≥19 species were included in the specimens. Culicoides oxystoma, which is a known major vector of Akabane virus (AKAV), appeared not to have expanded in northern Honshu during the surveillance. Of the potential AKAV vectors suggested by a previous laboratory experiment, C. tainanus and C. punctatus widely infested cowsheds across northern Honshu. The AKAV circulation was confirmed by serological surveillance of sentinel cattle in northern Honshu during the summer and autumn of 2010 and, consequently, >200 calves affected by the virus were identified as of spring 2011. Our surveillance demonstrated that C. tainanus and C. punctatus were widely spread and often dominated at cattle farms in/around the seroconverted regions, and our results thus suggest that these species played a critical role in the AKAV transmission in 2010. Because the distribution ranges of C. tainanus and C. punctatus cover almost all of mainland Japan, a potential risk of AKAV transmission might be expected even in areas outside the range of C. oxystoma. [ABSTRACT FROM AUTHOR]

Background: Biting midges (Ceratopogonidae) are capable of transmitting a variety of pathogens including viruses, trypanosomes and haemosporidia. The majority of Haemoproteus parasites are transmitted by biting midges predominantly of the genus Culicoides and are known to cause significant physical and reproductive impacts on both wild and domestic birds. In Japan, Haemoproteus had been detected from various avian hosts, but not from arthropod vectors. In this study, we investigated the prevalence of avian haemosporidia at an educational forest in central Japan in attempt to reveal possible vector species of Haemoproteus, which would help to better understand the transmission cycle of Haemoproteus within Japan and to develop preventative measures for captive and domestic birds., Methods: Biting midges were caught using UV light traps from 2016 to 2018. The collected samples were morphologically identified, and haemosporidian parasites were detected using PCR-based methods. The detected lineages were phylogenetically analyzed and compared with lineages previously detected from birds. Bloodmeal analyses were also carried out for part of the blood-fed individuals., Results: Six Haemoproteus lineages were detected from 17 of 1042 female Culicoides (1.63%), including three species (C. sigaensis, C. arakawae, and C. pictimargo) in which Haemoproteus was detected for the first time. All detected lineages were placed in the subgenus Parahaemoproteus clade and were previously detected from crows of central Japan, strongly suggesting that parasites of these genetic lineages are transmitted between Culicoides and crows. Two Plasmodium lineages were also detected but are thought to be transmitted between Culex mosquitoes and birds of the educational forest based on previous detections. No amplifications were seen in bloodmeal analysis, possibly due to insufficient amount of blood, denaturation via digestion, or insufficient detectability of the used protocol., Conclusion: Haemoproteus DNA was detected from Culicoides for the first time in Japan, suggesting that transmission is possible within the country. These findings highlight the necessity to investigate Culicoides populations and Haemoproteus infections dynamics in Japan. However, vector competence could not be confirmed in this study and further studies are anticipated., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The article presents a study on the detection of the activities of Culicoides brevitarsis in Kyushu, Japan. In the entomological surveys which was conducted by a group of researchers in 2008, samples of Culicoides brevitarsis were collected from eight locations in Japan near pastures where the cattle dung was left in the field. The study confirmed that this organism is present at the same site for two consecutive years which, according to the researchers, suggested that it overwinters in Kyushu.

Background: Akabane virus is a member of the genus Orthobunyavirus in the family Bunyaviridae. It is transmitted by hematophagous arthropod vectors such as Culicoides biting midges and is widely distributed in temperate to tropical regions of the world. The virus is well known as a teratogenic pathogen which causes abortions, stillbirths, premature births and congenital abnormalities with arthrogryposishydranencephaly syndrome in cattle, sheep and goats. On the other hand, it is reported that the virus rarely induces encephalomyelitis in cattle by postnatal infection. A first large-scale epidemic of Akabane viral encephalomyelitis in cattle occurred in the southern part of Japan from summer to autumn in 2006. The aim of this study is to define the epidemiological, pathological and virological properties of the disease. Results: Nonsuppurative encephalomyelitis was observed in cattle that showed neurological symptoms such as astasia, ataxia, opisthotonus and hypersensitivity in beef and dairy farms by histopathological analysis. Akabane viral antigen and genome were consistently detected from the central nervous system of these animals, and the virus was isolated not only from them but also from the blood samples of clinically healthy calves in the epidemic area. The isolates were classified into genogroup I a containing the Iriki strain, which caused encephalitis of calves almost twenty years ago in Japan. Most of the affected cattle possessed the neutralizing antibody against Akabane virus. Seroconversion of the cohabitated and sentinel cattle in the epidemic area was also confirmed during an outbreak of the disease. Conclusion: The ecological and epidemiological data we have obtained so far demonstrated that the Akabane virus is not endemic in Japan. No evidence of Akabane virus circulation was observed in 2005 through nation-wide serological surveillance, suggesting that a new strain belonging to genogroup I a invaded southern Japan from overseas in the summer of 2006 and caused an unprecedented epizootic of encephalomyelitis mainly in susceptible calves. It will be necessary to reconsider the vaccine strategy to control the disease effectually. [ABSTRACT FROM AUTHOR]

Six virus isolations were made fromCulicoidesbiting midges and blood samples of sentinel cattle in Kagoshima and Miyazaki Prefectures, the southern part of Japan, in 2002. Serological and genetical tests identified these viruses as isolates ofShamonda virus(SHAV), which belongs to the Simbu group of the genusOrthobunyavirusof the familyBunyaviridae. Initially, SHAV was isolated from cattle andCulicoidesbiting midges in Nigeria in the 1960s, and its presence has not been reported until this study. The present results indicate a wider distribution of SHAV than previously assumed. [ABSTRACT FROM AUTHOR]

Summary. The viruses were isolated from the blood of sentinel cattle and Culicoides biting midges in the Kyushu district, southwestern Japan, in 1999 and identified by neutralization tests as Peaton (PEA) viruses. Before this study, PEA virus had been isolated in Australia only. The nucleotide identity of the nucleocapsid (N) protein encoded by the S segment ranged from 91.1 to 91.6% between the Australian and Japanese strains. A phylogenetic analysis of the N protein sequence revealed that the PEA virus strains are closely related to Aino (AIN) virus and suggested reassortment events for PEA and AIN viruses. [ABSTRACT FROM AUTHOR]

Abstract: Camp Zama, Japan, and the associated military housing and depot storage areas have been occupied by the US military for over 50years. The military base has experienced less urbanization and development during those 50years when compared to the surrounding cities of Zama and Sagamihara. We present an annotated comparative checklist of historical records of biting flies (mosquitoes, black flies, biting midges, stable flies, and horse flies) with recent collections. Overall 24 species of biting flies have been reported from Camp Zama, with 17 of these species collected during the last 5years. Vectors of human and veterinary pathogens were collected including Anopheles sinensis, Aedes albopictus, Culex tritaeniorhynchus, and Simulium bidentatum. [Copyright &y& Elsevier]