Conservation biology for the commercial insect trade in Japan: agricultural bumblebees and companion insects as examples.

Japan imports a wide range of arthropods for industrial use and as companion animals. Such imports may threaten ecosystems locally and in their regions of origin. Two iconic insect imports that pose ecological problems are agricultural bumblebees and companion beetles. Colonies of the bumblebee Bombus terrestris have contributed significantly to agricultural production since they were first brought to Japan in the 1990s. But, in their progressive feralisation, they harm populations of native bumblebees through competition, hybridisation, and the introduction of parasites. They also threaten native plant reproduction. The species is currently permitted for agricultural use only in netted greenhouses. Since 2000, imports of companion beetles have thrived, with an estimated market size of many billions of yen. The popularity of rare species has led to a sharp rise in prices, overhunting, and smuggling from their native countries. These exotic species may also become invasive if they escape into nature. There are no clear restrictions on beetle imports, but a government campaign is aimed to improve ethical standards for breeding. In addition, imported tarantulas, centipedes and scorpions are becoming increasingly popular. These species pose similar threats as imported beetles and bees, but the actual state of importation and breeding is difficult to ascertain. Importing insects into Japan can create the following issues: the overexploitation of rare species collected from their native habitats; the traffic in species of which collection and sale is prohibited; the risk that escaped individuals will breed as invasive species; and the introduction of alien microorganisms and parasites.

Le Japon importe un large éventail d'arthropodes pour un usage industriel mais aussi en tant qu'insectes de compagnie. Ces importations représentent une menace potentielle tant pour les écosystèmes locaux que pour leurs régions d'origine. S'agissant des deux insectes iconiques que sont les bourdons pollinisateurs et les coléoptères de compagnie, les importations posent de nombreux problèmes écologiques. Les colonies de bourdons Bombus terrestris ont fortement contribué à la production agricole depuis leur première introduction au Japon dans les années 1990. Cependant, une fois installés et retournés progressivement à l'état sauvage, ils nuisent aux populations natives de bourdons par la compétition qu'ils exercent à leur encontre, la survenue d'hybridations spontanées et l'introduction de parasites. Ils représentent aussi une menace pour la reproduction des plantes natives. L'utilisation de cette espèce en agriculture n'est actuellement autorisée que dans des serres fermées. Depuis 2000, les importations de coléoptères de compagnie ont prospéré et représentent un marché estimé à plusieurs milliards de yens. La popularité des espèces rares a entraîné une forte hausse des prix, un excès de captures et un essor de la contrebande depuis leurs pays d'origine. Ces espèces exotiques peuvent également devenir envahissantes si elles s'échappent dans la nature. Les importations de coléoptères ne font l'objet d'aucune restriction légale mais le gouvernement a lancé une campagne visant à améliorer les normes éthiques des élevages. En outre, les tarentules, les myriapodes et les scorpions d'importation gagnent aussi en popularité. Ces espèces posent des menaces similaires à celles des abeilles et des coléoptères importés, mais l'échelle des importations et des élevages les concernant est difficile à déterminer avec certitude. Les problèmes que peuvent générer les importations d'insectes au Japon sont les suivants : une surexploitation des espèces rares prélevées dans leurs habitats natifs ; le trafic illicite d'espèces dont la collecte et la vente sont interdites ; le risque que des insectes échappés dans la nature puissent se reproduire, l'espèce devenant alors envahissante ; le risque d'introduction de microorganismes et de parasites exotiques.

El Japón importa muy diversos artrópodos que son destinados a usos industriales o utilizados como mascota. Estas importaciones pueden entrañar una amenaza para los ecosistemas, tanto en los lugares de destino como en sus regiones de origen. Dos importaciones emblemáticas de insectos que causan problemas ecológicos son las de abejorros de uso agrícola y las de escarabajos utilizados como mascota. Desde que en el decenio de 1990 fueron introducidas por primera vez en el Japón, las colonias de abejorro común (Bombus terrestris) han revestido gran utilidad para la producción agrícola. Ahora bien, su progresiva feralización resulta perjudicial para las poblaciones de abejorros nativos, debido a los fenómenos de competencia, hibridación e introducción de parásitos que la acompañan, y pone también en peligro la reproducción de ciertas plantas nativas. Actualmente solo está autorizado el uso agrícola de esta especie en invernaderos cerrados con malla. Desde el año 2000 vienen aumentando las importaciones de escarabajos que se utilizan como mascota, hasta el punto de que ello supone hoy, según los cálculos, un mercado de miles de millones de yenes. La popularidad de ciertas especies raras ha traído consigo una fuerte subida de los precios, capturas excesivas y contrabando de esas especies desde sus países de origen. Si escapan al medio natural, además, estas especies exóticas también pueden devenir invasoras. Las importaciones de escarabajos no están sujetas a restricciones claras, aunque el Gobierno tiene instituida una campaña para mejorar la deontología de las normas de cría. Por otro lado, cada vez hay más querencia por tarántulas, ciempiés y escorpiones importados. Estas especies entrañan amenazas análogas a las que plantean escarabajos y abejas de importación, pero resulta difícil determinar cuál es la situación actual por lo que respecta a su importación y cría. La importación de insectos al Japón puede acarrear los siguientes problemas: la sobreexplotación de especies raras en su hábitat nativo; el tráfico de especies cuya captura y venta están prohibidas; el riesgo de que haya ejemplares que escapen y se reproduzcan hasta devenir especie invasora; y la introducción de microorganismos y parásitos foráneos.

Cumulative ecological impacts of two successive annual treatments of imidacloprid and fipronil on aquatic communities of paddy mesocosms.

Agricultural landscapes, including paddies, play an important role in maintaining biodiversity, but this biodiversity has been under the threat of toxic agro-chemicals. Our knowledge about how aquatic communities react to, and recover from, pesticides, particularly in relation to their residues, is deficient, despite the importance of such information for realistic environmental impact assessment of pesticides. The cumulative ecological impacts on aquatic paddy communities and their recovery processes after two successive annual applications of two systemic insecticides, imidacloprid and fipronil, were monitored between mid-May and mid-September each year. The abundance of benthic organisms during both years was significantly lower in both insecticide-treated fields than in the controls. Large-impacts of fipronil on aquatic arthropods were found after the two years. Growth of medaka fish, both adults and their juveniles, was affected by the application of the two insecticides. A Principal Response Curve analysis (PRC) showed the escalation and prolongation of changes in aquatic community composition by the successive annual treatments of each insecticide over two years. Residues of fipronil in soil, which are more persistent than those of imidacloprid, had a high level of impact on aquatic communities over time. For some taxonomic groups, particularly for water surface-dwelling and water-borne arthropods, the second annual treatment had far greater impacts than the initial treatment, indicating that impacts of these insecticides under normal use patterns cannot be accurately assessed during short-term monitoring studies, i.e., lasting less than one year. It is concluded that realistic prediction and assessment of pesticide effects at the community level should also include the long-term ecological risks of their residues whenever these persist in paddies over a year.

Biosecurity measures to prevent the incursion of invasive alien species into Japan and to mitigate their impact.

The 2004 Japanese 'Invasive Alien Species Act' was enacted to control invasive alien species and prevent the damage that they cause to ecosystems. The Act defines invasive alien species as those recognised as, or suspected of, causing damage to ecosystems, human safety, agriculture, forestry and fisheries. Invasive alien species are carefully regulated: raising, planting, keeping or transporting them is prohibited without the express permission of the relevant minister. The Act represents a revolutionary advance for biological conservation in Japan. However, enforcing the Act is problematic. Dealing with the European bumblebee (Bombus terrestris), for example, involved resolving a bitter dilemma between biological conservation and agricultural productivity. The Act also has a serious loophole; it does not include alien micro-organisms. The incursion of amphibian chytridiomycosis into Japan caused confusion for scientists and the Japanese Government because control of such an alien micro-organism was not anticipated in the Act. Japan faces particular difficulties in attempting to control alien species because of its reliance on imports.

Genetic basis of resistances to chlorfenapyr and etoxazole in the two-spotted spider mite (Acari: Tetranychidae).

We studied the genetic basis of resistance to two new acaricides, chlorfenapyr and etoxazole, which have different chemical structures and modes of action in the two-spotted spider mite, Tetranychus urticae Koch. The resistance ratios calculated from the LC50s of resistant and susceptible strains were 483 for chlorfenapyr and >100,000 for etoxazole. Mortality caused by the two acaricides in F1 progeny from reciprocal crosses between the resistant and susceptible strains indicated that the modes of inheritance of resistance to chlorfenapyr and etoxazole were completely dominant and completely recessive, respectively. Mortality in F2 progeny indicated that for both acaricides, the resistance was under monogenic control. Repeated backcross experiments indicated a linkage relationship among the two acaricide resistances and malate dehydrogenase, although phosphoglucoisomerase was not linked with them. The recombination ratio between the resistances was 14.8%. From this result, we suggest that heavy spraying of the two acaricides will lead to apparent cross-resistance as a consequence of crossing over; the two resistance genes are so close to each other that it would be difficult to segregate them once they came together on the same chromosome.

Wildlife disease. Recent introduction of a chytrid fungus endangers Western Palearctic salamanders.

Emerging infectious diseases are reducing biodiversity on a global scale. Recently, the emergence of the chytrid fungus Batrachochytrium salamandrivorans resulted in rapid declines in populations of European fire salamanders. Here, we screened more than 5000 amphibians from across four continents and combined experimental assessment of pathogenicity with phylogenetic methods to estimate the threat that this infection poses to amphibian diversity. Results show that B. salamandrivorans is restricted to, but highly pathogenic for, salamanders and newts (Urodela). The pathogen likely originated and remained in coexistence with a clade of salamander hosts for millions of years in Asia. As a result of globalization and lack of biosecurity, it has recently been introduced into naïve European amphibian populations, where it is currently causing biodiversity loss.

Embryotoxicity of zinc pyrithione, an antidandruff chemical, in fish.

Early-life-stage toxicity tests of zinc pyrithione (Zpt) and commercial shampoos containing or not containing Zpt were performed on zebra fish and Japanese Medaka. The results showed that Zpt induced significant teratogenic effects on larvae of both species of fish. The two antidandruff shampoos containing Zpt induced the same teratogenic effects as Zpt. The calculated EC50 concentrations of Zpt for each of the shampoos were consistent with the EC50 for Zpt concentrate. Furthermore, 23 other shampoos not containing Zpt showed no teratogenic effects. These results strongly suggest that Zpt is the main factor in the antidandruff shampoos.

Bumblebee commercialization will cause worldwide migration of parasitic mites.

We investigated natural populations of three Japanese native bumblebee species to determine the status of infestation by a tracheal mite, Locustacarus buchneri, which we had earlier detected in introduced commercial colonies of the European bumblebee, Bombus terrestris. We also investigated mite infestation in commercial colonies of a Japanese native species, B. ignitus, which are mass-produced in the Netherlands and reimported into Japan. We detected the mite in both natural and commercial colonies of the Japanese species. Comparison of 555 bp sequences of the mitochondrial DNA (mtDNA) cytochrome oxidase 1 (CO1) gene from the mite showed that there were seven haplotypes, on the basis of combinations of substitutions at eight sites in the gene. The haplotypes of the mites in the Japanese native bumblebees and the haplotypes of the mites in B. terrestris did not overlap; however, mtDNA of mites detected in the commercial colonies of B. ignitus possessed the same sequence as a European haplotype. These results indicate that transportation of bumblebee colonies will cause overseas migration of parasitic mites of different origins.

Molecular cloning and characterization of a microsatellite locus found in an RAPD marker of a spider mite, Panonychus citri (Acari: Tetranychidae).

Genetic markers were searched using PCR with 40 kinds of decanucleotide primers to investigate DNA polymorphism in Panonychus citri. A region consisting of a variable number of CT tandem repeats (microsatellite) was found in a fragment amplified with the OPB10 primer. The microsatellite differed in size by ca. 100bp among several P. citri populations screened and was derived from at least seven alleles. This region was characteristic of P. mori and P. osmanthi, but was lacking in P. ulmi. The flanking regions were highly conserved among these species.