2007 Fiscal Year Final Research Report Summary
Study onstructure and function of micro-arthropoda community by system approach.
| Project/Area Number |
17370005
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Ecology/Environment
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| Research Institution | Hokkaido University |
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Principal Investigator |
SAITO Yutaka Hokkaido University, Res. Fac. Of Agriculture, Professor (20142698)
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| Co-Investigator(Kenkyū-buntansha) |
TAKADA Takenori Hokkaido University, Graduate School of Environmental Earth Science, Professor (80206755)
SAHARA Ken Hokkaido University, Res. Fac. Of Agriculture, Assistant Professor (30241368)
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| Project Period (FY) |
2005 – 2007
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| Keywords | Biology / Behavioral ecology / Evolution / Animal / Community / Spider mites / Phytoseiidae / Stigmaeidae |
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| Research Abstract |
On gramineous plants, it has been know that there is complex plant mite fauna. Especially, on Sasa bamboo in Hokkaido region, 9 species of spider mites and 7 species of predacious mites were sympatrically distributed. Why there is so much diversified fauna in this plant may concern the structure and function of community. Then we have studied on the plant-inhabiting mite fauna on Sasa in relation to the other gramineous plant species, such as the species of the genera Sasa, Phyllostachys, Bamusa and Miscanthus.
We have discovered in this research program: There was much variation in physiological adaptation, i.e. diapauses of several spider mites inhabiting Sasa and Miscanthus. How vary genetically the mites inhabiting Miscanthus in the wild populations was observed and we have detected inbreeding depression of female fecundity by genetic factors retained in natural populations. Furthermore, we have established a molecular phylogeny hypothesis of Stigmaeopsis. Then we knew that there wa
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s a speciation through host-plant shift. We have observed much variation in male-male interactions in Stigmaeopsis species on Sasa and Miscanthus. We have developed a new game model to explain its variation as well as the conditions under which symbiotic relationships between species evolves. We have learned that there are communal relationships in a social spider mite, Stigmaeopsis longus. There are special nest sanitation behaviors in Stigmaeopsis mites. We have discovered that this behavior was controlled by chemical communication systems. We have studied on anti-predator behaviors of several mite species inhabiting Sasa, then we have known that tactile crypsis against non-visual predators exists in the spider mite, Aponychus corpuzae. In addition, we have discovered that scattering nests of Stigmaeopsis species function as a hindering strategy to decrease predation risk. Lastly, we have developed a system model that can simulate two different plant systems each having a single specific pest mite and a common predator species that can prey both prey species in these two plant systems. The model could predict that both the prey-predator systems can be stabilized by the predator immigration/emigration rates. Less
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