水田におけるアメリカカブトエビの個体数変動

概要

論文の詳細を見る
Population dynamics of Triops longicaudatus LECONTE was studied from 1981 to 1982 in a paddy field of Hiroshima Agricultural College at Higashi Hiroshima City, Hiroshima Prefecture. Four plots were established in a paddy field. Initial densities of young forms in 1982 were 1/5-1/10 higher than those in 1981,while the densities of eggs were almost equal in the soil, presumably due to the low hatchability of the eggs associated with the high water temperature in 1982. Predators were seldom observed during the study period. Mortality rates were density-independent. Carapace length growth was density-dependent, so that the mean body size in 1982 was larger than in 1981. It was estimated that the egg production per female in 1982 was higher than that in 1981. No differences in total egg production per plot were observed between 1981 and 1982. About 60% of the eggs did not hatch after flooding and ploughing and were carried over to the next season. It is suggested that the population of T. longicaudatus was potentially stable in each generation, but that it became unstable due to the influence of external factors, such as weather conditions, pesticide application and water level management of the paddy field.
日本応用動物昆虫学会の論文
1985-11-25