長野県伊那地方におけるオオニジュウヤホシテントウ群の生態 : II.アザミを寄主とするヤマトアザミテントウの個体群動態

概要

論文の詳細を見る
From 1978 to 1980,two population of Henosepilachna niponica feeding on wild thistle (Cirsium spp.) were studied in different habitats, Sawai and Kashio at Ohshika village, Nagano Prefecture, by construction of life tables and mark-recapture of adults. The life histories of the two populations were seasonally synchronous with the phenology of the host plant and population densities never reached a level where food shortage occurred. Both populations were characterized by high mortality(95-97%)during the immature stages due to egg cannibalism by adults, and predation by polyphagous arthropods on eggs, larvae and pupae. The reproductive rate(=no. of newly emerged females per overwintered female)during the three-year study period was low in both populations, that in Sawai(0.9-1.8)being more stable than that in Kashio(1.3-5.4). According to key factor analysis, the variation in number of eggs laid per female was the major factor responsible for the variation in reproductive rate seen in Sawai. No clear tendencies were evident in Kashio. The reason for this difference in variation pattern between the two population was obscure. The variation in number of eggs laid per female also seemed to play an important role in stabilizing population densities in both populations.
日本生態学会の論文
1987-12-31