| Takatoshi Ueno | Last modified date：2023.11.27 |
Associate Professor /
Institute of Biological Control /
Department of Bioresource Sciences /
Faculty of Agriculture
Presentations
| 1. | 上野 高敏, Flower-Visiting by the Invasive Hornet Vespa Velutina Nigrithorax (Hymenoptera: Vespidae), International Multi Conference on Chemical, Environmental and Medical Sciences, 2015.12. |
| 2. | 上野 高敏, Environmentally Sound Agriculture and Biological Indicators in Rice Paddies, Global Conference on Entomology, 2013.11, Rice is the main food in Asia, where rice paddy systems are traditionally used for the production of rice. Rice paddies, together with the associated irrigation ponds, ditches and ridge, often constitute the traditional landscape in rural environments. Rice paddies commonly occupy the largest cultivated area among agricultural land, and form an ecosystem representing a major semi-natural environment with high biodiversity. Insect natural enemies inhabiting rice paddies have an important function for rice production as agents of ‘ecosystem services’ because they play a major role in suppressing rice pests. The diversity and abundance of natural enemies can be a good index reflecting the ‘healthiness’ of agro-ecosystem services in rice paddies. The present study investigates whether insect natural enemies could be good biological indicators for general arthropod biodiversity and agricultural practice. First, the concept of ideal bio-indicators was summarized. The strategy to explore and select such bio-indicators was then proposed. Lastly, the results of field survey was given to evaluate whether the abundance and biodiversity of natural enemies in Japanese rice paddies could be good indicators to assess environmental soundness of agricultural practices and general biodiversity. The results showed that reduction of pesticide use led to an increase in species richness or diversity of natural enemies including parasitoids and predators. Use of chemical manure enhanced parasitoid diversity. The density of several species of natural enemies did respond both to pesticide use and to general arthropod biodiversity. The analyses thus have indicated that natural enemies are suitable bio-indicators. Usefulness of indicator species in rice paddies is discussed in the context of ecologically sound agriculture.. |
| 3. | Takatoshi Ueno, Insect natural enemies as bioindicators in rice paddies, International Symposium on Agriculture, Food, Environmental and Life Science in Asia, 2012.11. |
| 4. | Takatoshi Ueno, Environmentally Sound Agro-practice, Biodiversity and Indicator Species in Rice Paddies, International Conference on Ecological, Environmental and Biological Sciences (EEBS'2012), 2012.10, Abstract—Rice paddies occupy the largest cultivated area in agricultural land and provide the habitats for many organisms. Thus, rice paddies are a key ecosystem in agricultural land that sustains a high level of agro-biodiversity. Natural enemies have an important function for crop production as agents of ‘ecosystem services’ because they play a major role in suppressing pests. The diversity and abundance of natural enemies can be a good index reflecting the ‘healthiness’ of agro-ecosystem services in rice paddies. In the present study, a survey was made to investigate the abundance and biodiversity of natural enemies in rice paddies where chemical inputs, i.e., insecticide use, were different. The reduction of chemical inputs led to an increase in species richness or diversity of natural enemies like parasitoids and spiders. Then, it was analyzed to explore suitable indicator species to assess environmental soundness of agricultural practice and biodiversity in rice paddies. Seven spotted ladybird beetle, Coccinella septempunctata, (Coleoptera: Coccinellidae) and a web-constructing araneid spider, Neoscona adianta, (Araneae: Araneidae) were among the commonest species of predators detected in paddy fields, and were tested to examine whether the density of the two could reflect the levels of chemical input and biodiversity. The density of the ladybird did not respond both to pesticide use and to biodiversity, indicating that this species was not suitable as an indicator. In contrast, the araneid spider increased both with a reduction of pesticide use and with an increase of biodiversity. Neoscona adianta was hence a good candidate of natural enemies to assess agricultural practice and biodiversity in rice paddies. Thus, it is possible to select species that are ideal bioindicators for monitoring both environmental soundness and biodiversity in agriculture. Usefulness of indicator species in rice paddies is discussed.. |
| 5. | Takatoshi Ueno, Use of natural enemies as a bio-indicator for assessing environmental soundness of agricultural practices in rice paddies, 24th International Congress of Entomology, 2012.08. |
| 6. | Soichiro Tani, Takatoshi Ueno, Adaptive signifi cance of homing behavior in male scoliid wasps (Hymenoptera: Scoliidae), 24th International Congress of Entomology, 2012.08. |
| 7. | Hiroki Itadani, Takatoshi Ueno, The mating system using volatile and substrate-born sex pheromones in a polyphagous solitary parasitoid wasp, Itoplectis naranyae, 24th International Congress of Entomology, 2012.08. |
| 8. | 上野 高敏, Biodiversity and assessment of environmental friendship of farming practices in rice paddies, 2nd World Biodiversity Congress, 2011.09. |
| 9. | Takatoshi Ueno, Functional biodiversity in rice paddies and exploring indicator species that reflect environmentally benign agricultural practices, 7th International AFAS Joint Symposium Between Korea and Japan, 2010.10. |
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| 11. | An ecological reason why parasitism levels of alfalfa weevil by an introduced parasitoid Bathyplectes anurus remain low on Chinese milk vetch.. |
| 12. | : Much attention has recently been paid to biological threats posed by invasive exotic species. As global trade keeps increasing, new invasive species have been emerging. Strategies to combat invasive species are then essential to conserving our native environment and protecting agricultural production. Prevention is the most preferred method but cannot be perfect. Mechanical, chemical and biological control are major approaches to combat once established species. Here, biological control was focused as an environmentally benign approach. Brief review of biological control was given first. Recent progress of classical biological control of alfalfa weevil with an introduced parasitoid wasp was then demonstrated as a successful example of invasive pest management in Japan. The most important concept of biological control is that this approach basically does not intend to eradicate invasive species; we have to accept them as a member of the fauna in areas of invasion but keep them at low population levels that are not seriously harmful to native ecosystem and agriculture, with the aid of introduced specialist natural enemies, which are also allowed to establish in the areas. Keywords: classical biological control, natural enemies, pest management, invasive species, biological conservation. |
| 13. | The alfalfa weevil, Hypera postica, was accidentally introduced into Japan in 1980’s, and becomes the most destructive pest of Chinese milk vetch in the western region of Japan since then. Chinese milk vetch is the high-value source of honey production for apiculture, and the problem is that insecticides cannot be a primary option to combat the pest because of a potential contamination of chemicals into honey products. Biological control is then a significant approach to manage alfalfa weevil. Because no native natural enemies were found effective to suppress the weevil populations, Bathyplectes anurus, an ichneumonid parasitoid, was introduced in 1990’s for the classical biological control of the weevil. This parasitoid species is exactly host-specific and does not affect any other native insects. Although this parasitoid provides a successful control of alfalfa weevil in Kitakyushu area now, abundance of the parasitoid is often much lower in Chinese milk vetch fields than leguminous forbs, in particular Vicia angustifolia, fields. Biological factors affecting the difference in parasitism rates between the two host plants were examined in order to find the approach to increase parasitoid abundance in Chinese milk vetch. Laboratory and semi-field experiments showed that this difference partly resulted from the presence of plant preference in B. anurus but such plant preference appears not to provide a full explanation of low level of parasitism in Chinese milk vetch. We speculated that the difference in adult-food abundance could explain the differential parasitism rates in the field, and conducted a series of laboratory, semi-field and field experiments to examine whether adult food could be a factor influencing parasitoid activity in the field. No adult parasitoids were found to feed on nectar of Chinese milk vetch and other leguminous flowers in the laboratory and field. However, both adult B. anurus showed a strong, innate preference for extrafloral nectar glands of Vicia angustifolia in laboratory and semi-field conditions. Experience did elevate their already high level of responsiveness to the nectar glands. When extrafloral nectar was present, their searching responses were largely strengthened. Further, longevity of adult B. anurus was enhanced by access to extrafloral nectar. In the field, the hunger level of adult B. anurus was confirmed to be higher in Chinese milk vetch than V. angustifolia fields. Our field observations also suggested that nectar not from flowers but from extrafloral nectaries provided parasitoids with essential carbohydrates as energy resources. Extrafloral nectarines provided by V. angustifolia should enhance the build-up of parasitoid population and increase the level of weevil parasitism. Our study demonstrates the importance of adult food in biological control with parasitoids.. |
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