Author
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Hirano K
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著者
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平野耕治
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Title
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Population dynamics of a phytophagous lady-beetle, Epilachna
vigintioctopunctata (Fabricius) (Coleoptera: Coccinellidae), living in
spatio-temporally Heterogeneous habitats II. Seasonal changes in adult
movement and spatial distribution of the population
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タイトル
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生息地が不均質で不連続な環境におけるニジュウヤホシテントウ個体群動態の研究 II.
成虫の移動分散と個体群の空間分布の季節的変化
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Keywords
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interpatch movement, density-dependent movement, food resource,
mechanism stabilizing population, fluctuation, regulatory
process
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Abstract
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The population process of the phytophagous lady beetle, Epilachna
vigintioctopunctata, was studied in spatio-temporally heterogeneous
habitats in order to clarify the seasonal changes in interpatch movement
of adults, density effect on the movement, and the effect of the movement
on the spatial distributions of the population. The population censuses
were carried out for three years in an area of about 15 ha containing 18
distinguishable patches of host plants. The rate of interpatch movement of
females tended to be highest in the first generation adults, moderate in
the second generation adults, and lowest in the over-wintered adults. The
movement rate of females tended to increase incrementally with adult
density. This density-dependent interpatch movement of females which
accompanied mortality in the dispersal process reduced the patch variation
in the densities of females and eggs, and was thought to be the most
important factor in stabilizing the yearly fluctuation of population
density.
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要旨
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Journal
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Appl.Ent.Zool., 28(2), 1993, p.131-140.
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