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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. Among the 18 insecticides considered, 15 were detected somewhere in Japan and their concentrations were generally higher in the southwestern region in Japan (e.g. Hiroshima, Saga, or Kagoshima prefectures). Most insecticides were accumulated at higher concentrations in sediment than in surface water, consistent with previous studies. We also detected insecticides applied to nursery boxes at high concentrations in surrounding aquatic areas, although such application is generally considered to have low environmental risks. In addition, derivatives of fipronil, which have similar toxicity as that of fipronil, were often detected in sediment at higher concentrations than fipronil itself. Concentrations of dinotefuran in water at two sampling points were higher than the 5% hazardous concentration (HC5), indicating a possibility of a risk of acute toxicity to aquatic organisms. Our findings indicate that ecological risk assessments of insecticides and their derivatives should be expanded to include concentrations in sediment and water around paddy fields as well. Locations of 11 survey sites and the mean amounts (log+1 transformed) of pesticides detected in sediment (s; μg/kg) and water (w; μg/L) samples. Image 1 • Many insecticides were detected in sediment and water around paddy fields. • Sediment accumulated higher concentration of fipronil derivatives than fipronil. • Dinotefuran concentration often exceeded its community toxicity benchmark. • Environmental risk assessments of pesticides should be more inclusive. We revealed many insecticides and derivatives were detected in sediment and water around paddy fields, arising a possibility of an environmental impact. [ABSTRACT FROM AUTHOR]

The researchers examined female-female interactions in termite colonies founded by two unmated females. The research was undertaken to help determine the costs and benefits of queen association in termites.

Our goal was to create colonization and invasion risk maps for the Argentine ant, Linepithema humile , based on occurrence data in Japan, by combining colonization- and invasion-related variables and spatial filters that alleviate spatial autocorrelation. With these data, we will be better able to implement surveillance and control programs. Species distribution models were generated, using the maximum entropy approach, from presence-only data collected from 12 locations. Colonization-related variables (e.g., temperature, precipitation) and invasion-related variables (e.g., urban area, distance from ports) were used as environmental variables and spatial filters that alleviate spatial autocorrelation were included at the same time. The high invasion risk area was restricted to coastal areas, whereas high colonization risk applied to a broader area. Elevation, minimum temperature, and flow accumulation were the most effective variables for predicting colonization risk, whereas urban area, elevation, and the port distance index were the most effective variables for predicting invasion risk. The invasion risk map had a higher level of accuracy than the colonization risk map. We identified those areas with a high risk of invasion in the early stages and strong propagule pressure with a model using both invasion-related variables and colonization-related variables to accurately estimate the initial invasion distributions. We found that high colonization risk areas were concentrated in the Okinawa and Ogasawara Islands; ecosystems with highly endemic ant species that are likely to have a high sensitivity to L. humile introduction. Our data will aid in strengthening both domestic and international quarantine systems to prevent such introductions. [ABSTRACT FROM AUTHOR]

A population of the perennial floating-leaved plant, Nymphoides peltata, in Lake Kasumigaura has declined rapidly in recent years, with no recruitment from seedlings. To obtain genetic information to facilitate a restoration program, we investigated allozyme polymorphisms in subpopulations from various parts of the lake. Only 14 multilocus genotypes were detected, although a relatively high percentage of polymorphic loci and high heterozygosity was present throughout the lake. Allozyme data indicated that the Lake Kasumigaura population consists of a single subpopulation that includes several clones consisting of two types of heterostylous floral morphs, and some subpopulations each consisting of a single clone. Preservation of the multiclonal subpopulation is essential for conserving the seed production and clonal diversity of N. peltata in Lake Kasumigaura. [Copyright &y& Elsevier]

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. In addition, the homology between the HA fragments in this and the Sanger methods ranged from 98.5 % to 100 %. Compared with conventional PCR with the Sanger method, this method can easily determine HA and NA subtypes and sequences directly from the fecal samples. It is easier to implement and has lower running costs (USD100$) than other NGS-based methods, making it a useful tool for avian influenza surveillance in wild birds. • We developed a method of sequencing AI from wild bird feces using Nanopore Flongle. • The sequencing accuracy of our method was comparable to the Sanger method. • Our method is a low-cost and scalable sequencing method. • The method is expected to be used for AI surveillance and other virus species. [ABSTRACT FROM AUTHOR]

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 (< LD50), neurotoxic insecticide molecules are known to influence the cognitive abilities of bees, impairing their performance and ultimately impacting on the viability of the colonies. In addition, widespread systemic insecticides appear to have introduced indirect side effects on both honey bees and wild bumblebees, by deeply affecting their health. Immune suppression of the natural defences by neonicotinoid and phenyl-pyrazole (fipronil) insecticides opens the way to parasite infections and viral diseases, fostering their spread among individuals and among bee colonies at higher rates than under conditions of no exposure to such insecticides. This causal link between diseases and/or parasites in bees and neonicotinoids and other pesticides has eluded researchers for years because both factors are concurrent: while the former are the immediate cause of colony collapses and bee declines, the latter are a key factor contributing to the increasing negative impact of parasitic infections observed in bees in recent decades. [ABSTRACT FROM AUTHOR]

Abstract: The infrequency of tsunamis results in a lack of knowledge regarding the impact they have on ecosystems. Comparison of the floristic composition before and after tsunamis using permanent plots is an effective approach to estimate the ecological impacts of tsunamis in coastal environments. Here, we report the floristic changes in beach vegetation in northern Tohoku, Japan caused by the 2011 Tohoku-oki tsunami. Among the beaches studied, we observed differences in the vegetative characteristics of the beach flora, whereas similarities were found in vegetation response patterns, particularly for herbaceous vegetation. No significant interaction was found between the overall number of vascular plant species or the number of non-beach species and the tsunami disturbance; conversely, on beaches that experienced relatively small impacts, the number of typical/characteristic beach species, Pielou evenness index values, and Shannon-Wiener diversity index values were significantly lower after the tsunami. Following the tsunami, the herbaceous vegetation species composition on all of the beaches was characterized by a few non-beach species that are known to tolerate strong anthropogenic disturbances; in contrast, the damage to shrub vegetation was lower than that to herbaceous vegetation. Our findings are similar to what was observed following the 2004 Indian Ocean tsunami in Thailand, suggesting that the initial response patterns of beach vegetation to tsunamis are similar, regardless of the affected climatic zone and species composition. Long-term field monitoring is needed to elucidate post-tsunami recovery, vegetation succession, and the ecological impact of the increase of non-beach species. [Copyright &y& Elsevier]

Abstract: We examined cytochrome P450 production and activity and circulating hormone concentrations in male medaka exposed to 17β-estradiol (E2) or 17α-ethinylestradiol (EE2). Intraperitoneal injection of E2 at 1, 10, or 100 μg/g-fish completely suppressed CYP3A38 protein production and suppressed CYP3A40 protein levels by 89%, 52%, or 47%, respectively. CYP3A38 and CYP3A40 mRNA expression was unaltered, and CYP3A enzymatic activity initially increased and then decreased with increasing E2 dose. Males co-cultured with females were exposed to a markedly high concentration (43 ng/L) of E2 secreted by females. CYP3A protein levels in co-cultured males were suppressed. Serum testosterone (TE) and 11keto-testosterone levels in co-cultured males were downregulated to 40% of pre-exposure levels. Serum E2 levels increased in co-cultured males or males exposed to EE2. Testicular CYP19, which converts TE to E2, increased by 9.5 times in males exposed to 50 ng/L EE2 and by 21.5 times in those exposed to 100 ng/L EE2. Male medaka exposed to EE2 showed increased serum Vtg levels. Estrogenic exposure induced Vtg production, suppressed CYP3A protein production, downregulated TE metabolism, and enhanced CYP19 activity. Serum E2 endogenously induced by CYP19 could contribute to Vtg induction in male medaka. [Copyright &y& Elsevier]

Abstract: Non-native pollinator species are now widely utilized to facilitate pollination of agricultural crops. Evaluation of the ecological risk of alien pollinators is necessary because they could have a large impact on native ecosystems through disturbing native plant–pollinator interactions. We conducted a greenhouse experiment to examine the impact of the non-native commercialized European bumblebees, Bombus terrestris, on the pollination success of seven Japanese bumblebee-pollinated plant species. Plants were exposed to three groups of bumblebees: native bumblebee(s) only (NATIVE treatment); the alien bee only (ALIEN) and a mix of the two (MIX). ALIEN treatment had negative effects on fruitset and/or fruit quality of five plants, including self-incompatible and compatible, herb and woody, and queen- and worker-pollinated species. The negative effects were caused by a decrease in legitimate flower visitation due to (1) physical inaccessibility to nectary in deep-corolla flowers by the alien bee with insufficient tongue length and, (2) biased flower preference between short-corolla flowers. Fruitset tended to decrease drastically for the self-incompatible species while fruit quality decreased moderately for the self-compatible species. Effects of MIX were not intermediate between NATIVE and ALIEN in most plant species, and caused pollination success to vary in an unpredictable manner amongst plant species, probably due to interaction between native and alien bees. This non-linear relationship between plants’ pollination success and the relative density of the alien suggests that the alien bee can disturb pollination of a plant species even when only representing a small fraction of the total pollinator community. [Copyright &y& Elsevier]

• The effects of three insecticides on animals in paddies were assessed for three years. • Animal community composition significantly differed among years. • Some taxa were decreased by each insecticide irrespective of year. • These taxa can be used as robust indicators of the effects of each insecticide. • Long-term monitoring may be useful in identifying ecotoxicological effect indicators. Semi-natural mesocosm experiments have been proposed as a powerful approach for evaluating the realised rather than potential ecotoxicological effects of agrochemicals on biological communities. However, there is uncertainty in the results from such experiments due to spatio-temporal variability in various ecological factors, such as community composition. Therefore, long-term studies evaluating such variability are critical for assessing the utility of mesocosm experiments, although few studies have been conducted over multiple years. We conducted a multiple-year (i.e., three-year) mesocosm experiment to examine the effects of three systemic insecticides (clothianidin, fipronil, and chlorantraniliprole) on aquatic animal communities in experimental paddies, and we evaluated the among-year variability in these ecotoxicological effects. We found substantial variation in community composition among years. However, when we controlled for this variability by performing partial redundancy analysis (partial RDA), we found that paddy community composition was significantly different between the three insecticide treatments irrespective of year. Moreover, we identified some taxa that consistently decreased in abundance following exposure to each insecticide and may thus be regarded as indicator taxa of the environmental stress caused by the insecticides (e.g., clothianidin: Gerris lacustris (water striders), fipronil: Orthetrum albistylum speciosum (dragonflies), and chlorantraniliprole: Hydroglyphus japonicus (beetles)). Our study suggests the utility of multiple-year, semi-natural mesocosm experiments not only for evaluating the temporal variability in ecotoxicological effects but also for identifying potential robust indicator organisms that consistently decrease in abundance in response to specific agrochemicals irrespective of the variability in ecological factors under realistic conditions. [ABSTRACT FROM AUTHOR]