Genetic population structure of the Asian longhorned tick, Haemaphysalis longicornis, in Japan.

The Asian longhorned tick, Haemaphysalis longicornis Neumann (Ixodida: Ixodidae), is widely distributed across temperate East Asia, including Japan, and carries a variety of zoonotic diseases. The species includes bisexual and parthenogenetic lineages. Various aspects of these two lineages, such as their abundance ratio, genetic relationship, and population structure, remain unknown in island environments such as Japan that are isolated from the mainland.

Multifaceted effects of variable biotic interactions on population stability in complex interaction webs.

Recent studies have revealed that biotic interactions in ecological communities vary over time, possibly mediating community responses to anthropogenic disturbances. This study investigated the heterogeneity of such variability within a real community and its impact on population stability in the face of pesticide application, particularly focusing on density-dependence of the interaction effect. Using outdoor mesocosms with a freshwater community, we found considerable heterogeneity in density-dependent interaction variability among links in the same community.

The impact of landscape structure on pesticide exposure to honey bees.

Pesticides may have serious negative impacts on bee populations. The pesticide exposure of bees could depend on the surrounding landscapes in which they forage. In this study, we assess pesticide exposure across various land-use categories, while targeting the Japanese honey bee, Apis cerana japonica, a native subspecies of the eastern honey bee.

Polyandry may mitigate the negative impact of reproductive interference among bumblebees in Japan.

In social hymenopterans, monandry of the queen is an ancestral trait, and polyandry is a derived trait. Polyandry of the queen is the norm in a limited number of lineages, such as honeybees, leaf-cutting ants, Pogonomyrmex ants, and Vespula wasps, which presumably provide fitness advantages for the whole colony. The queen of the introduced bumblebee, Bombus terrestris, is polyandrous in Japan, whereas it is monandrous in native regions.

Novel approach for detecting classical swine fever virus from swabs of wild boar cut tails using nested real-time PCR.

We devised a method to detect the classical swine fever virus (CSFV) in tail-wiped swabs from wild boars. The CSFV gene in swabs was detected with high sensitivity using nested real-time polymerase chain reaction (PCR), which is a combination of reverse transcription-PCR (RT-PCR) and real-time PCR. We compared CSFV gene detection from boar tissue using the conventional and our tail-wiped swab method.

Sequencing methods for HA and NA genes of avian influenza viruses from wild bird feces using Oxford Nanopore sequencing.

We developed a method to determine the sequences of hemagglutinin (HA) and neuraminidase (NA) from RNA extracted directly from wild bird fecal samples, using Nanopore Flongle. We determined the nucleotide sequences and subtypes of HA and NA in 16 and 15 samples respectively, using Flongle. The results of HA and NA subtyping determined by the conventional method were consistent with their subtypes determined by our method, thereby the applicability of this method in the identification of HA and NA subtypes.

Insecticide Residues Associated with Apple Orchard Treatments in the Mason Bee, Osmia cornifrons, and their Nests.

Declines in bee populations, in part due to pesticides, especially insecticides, are of global concern. Although most studies have investigated insecticide residues in honeybees and bumblebees, few have focused on non-Apis solitary bees, which are considered essential pollinators in the field. Most non-Apis bees are solitary and build their nests in the ground or in tree holes, therefore insecticide exposure pathways would differ from those of honeybees and bumblebees.

Acute toxicity data of common agricultural insecticides to Japanese wild bees.

Although numerous ecotoxicological assessments of European honeybee ( L.) have been performed, Japanese wild bees are less well studied in this regard. To address this knowledge gap, we assessed the mortality and acute toxicity (LD) of 3 common agricultural insecticides (clothianidin, fipronil, and diazinon) on as many as 6 species of Japanese wild bees ( Perez Radoszkowski Perez Tkalcu Perez and spp.

Efficiency of ant-control agents in colony-level oral toxicity tests using (Hymenoptera: Formicidae) for post-establishment control of the red imported fire ant, (Hymenoptera: Formicidae).

Unlabelled: The red imported fire ant Buren (Hymenoptera: Formicidae) causes serious damage worldwide as an invasive alien species. The species has expanded its range to the Pacific Rim since 2000s and Japan has faced its multiple introductions since 2017. While colony-level control methods are urgently needed, testing living colonies of the unestablished species is challenging especially due to various restrictions under the COVID-19 pandemic.

Distribution and Genetic Diversity of the Amphibian Chytrid in Japan.

While research on frog chytrid fungus , an infectious disease that threatens amphibian diversity, continues to advance worldwide, little progress has been made in Japan since around 2010. The reason for this is, which we pointed out in 2009, that the origin of frog chytrid fungus may be in the East Asian region, including Japan based on the ITS-DNA variation, and as few cases of mass mortality caused by this fungus have been observed in wild amphibian populations in Japan, the interest of the Japanese government and the general public in has waned. However, we believe that organizing the data obtained so far in Japan and distributing the status of frog chytrid fungus in Japan to the world will provide useful insight for future risk management of this pathogen.

Epidemiologic Survey of Avian Influenza Virus Infection in Shorebirds Captured in Hokkaido, Japan.

There is limited information about virus epidemiology of shorebirds (family Charadriidae and Scolopacidae) in the East Asia-Australasia flyway. We investigated the prevalence of avian influenza viruses (AIVs) in shorebirds in Hokkaido, Japan, the stopover site of the flyway, to understand the ecology of AIV translocation in the flyway from 2006 to 2010. In total, 1,698 shorebirds belonging to 26 species were captured and released into two different sites using mist nets.

Effects of a herbicide on paddy predatory insects depend on their microhabitat use and an insecticide application.

Indirect effects of agrochemicals on organisms via biotic interactions are less studied than direct chemical toxicity despite their potential relevance in agricultural landscapes. In particular, the role of species traits in characterizing indirect effects of pesticides has been largely overlooked. Moreover, it is still unclear whether such indirect effects on organisms are prevalent even when the organisms are exposed to direct toxicity.

Ecological risks of insecticide contamination in water and sediment around off-farm irrigated rice paddy fields.

The ecological impacts of insecticides in aquatic areas around agricultural lands have long been ignored in the regulation scheme of pesticides in Japan. Upon the scheme, the predicted concentration of an insecticide in the main stream of a river is the only parameter considered, suggesting that the ecological impacts of insecticides on local biodiversity around agricultural fields are underestimated. To fill this knowledge gap, we measured insecticide concentrations in surface water and sediment in aquatic areas around paddy fields at 35 locations across Japan.

Reproductive Interference in an Introduced Bumblebee: Polyandry may Mitigate Negative Reproductive Impact.

As a signature of reproductive interference (RI), we reviewed hybrid production in eusocial bumblebees in Japan, by comparing introduced with native in Honshu (main island of Japan) and with native in Hokkaido (northern island of Japan). In this review, we present additional new data showing hybrid production between introduced and native in Honshu. Interspecific mating with introduced disrupts the reproduction of native and , which belong to the same subgenus of , through inviable egg production.

Effects of short-term, sublethal fipronil and its metabolite on dragonfly feeding activity.

Dragonflies, Sympetrum spp., are indispensable to agriculture and are a central element of culture in Japan. However, S.

Author Correction: Declaration of local chemical eradication of the Argentine ant: Bayesian estimation with a multinomial-mixture model.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Declaration of local chemical eradication of the Argentine ant: Bayesian estimation with a multinomial-mixture model.

Determining the success of eradication of an invasive species requires a way to decide when its risk of reoccurrence has become acceptably low. In Japan, the area populated by the Argentine ant, Linepithema humile (Mayr), is expanding, and eradication via chemical treatment is ongoing at various locations. One such program in Tokyo was apparently successful, because the ant population decreased to undetectable levels within a short time.

Characterizing the temporal patterns of avian influenza virus introduction into Japan by migratory birds.

The objectives of the present study were to observe the temporal pattern of avian influenza virus (AIV) introduction into Japan and to determine which migratory birds play an important role in introducing AIV. In total, 19,407 fecal samples from migratory birds were collected at 52 sites between October 2008 and May 2015. Total nucleic acids extracted from the fecal samples were subjected to reverse transcription loop-mediated isothermal amplification to detect viral RNA.

Insecticide Susceptibility in Asian Honey Bees (Apis cerana (Hymenoptera: Apidae)) and Implications for Wild Honey Bees in Asia.

To conserve local biodiversity and ensure the provision of pollination services, it is essential to understand the impact of pesticides on wild honey bees. Most studies that have investigated the effects of pesticides on honey bees have focused on the European honey bee (Apis mellifera (Hymenoptera: Apidae)), which is commonly domesticated worldwide. However, the Asian honey bee (Apis cerana) is widely distributed throughout Asia, and toxicity data are lacking for this species.

Genetic Structure and Potential Environmental Determinants of Local Genetic Diversity in Japanese Honeybees (Apis cerana japonica).

Declines in honeybee populations have been a recent concern. Although causes of the declines remain unclear, environmental factors may be responsible. We focused on the potential environmental determinants of local populations of wild honeybees, Apis cerana japonica, in Japan.

Fipronil application on rice paddy fields reduces densities of common skimmer and scarlet skimmer.

Several reports suggested that rice seedling nursery-box application of some systemic insecticides (neonicotinoids and fipronil) is the cause of the decline in dragonfly species noted since the 1990s in Japan. We conducted paddy mesocosm experiments to investigate the effect of the systemic insecticides clothianidin, fipronil and chlorantraniliprole on rice paddy field biological communities. Concentrations of all insecticides in the paddy water were reduced to the limit of detection within 3 months after application.

Spatial assessment of the potential risk of avian influenza A virus infection in three raptor species in Japan.

Avian influenza A, a highly pathogenic avian influenza, is a lethal infection in certain species of wild birds, including some endangered species. Raptors are susceptible to avian influenza, and spatial risk assessment of such species may be valuable for conservation planning. We used the maximum entropy approach to generate potential distribution models of three raptor species from presence-only data for the mountain hawk-eagle Nisaetus nipalensis, northern goshawk Accipiter gentilis and peregrine falcon Falco peregrinus, surveyed during the winter from 1996 to 2001.

Are bee diseases linked to pesticides? - A brief review.

The negative impacts of pesticides, in particular insecticides, on bees and other pollinators have never been disputed. Insecticides can directly kill these vital insects, whereas herbicides reduce the diversity of their food resources, thus indirectly affecting their survival and reproduction. At sub-lethal level ( View Article and Find Full Text PDF