キャベツ株内におけるモンシロチョウの葉位別分布

抄録

Distribution of Pieris rapae crucivora on every leaf of cabbage plant was investigated by the censuses on the eggs and larvae. The eggs were distributed densely on mature leaves located in the middle part of a plant and sparsely on senescent leaves in lower part of it, The death rate of eggs was nearly the same with every leaf, but deaths were significantly less in densely laid plants than in sparsely laid plants on young or mature leaves. After hatching, the larvae became to be distributed more densely on young leaves in upper part of a plant with larval growth. Their inter-leaves movement may be due to their preference of young leaves as their food. The distribution of the number of eggs per plant was concentrating on young and mature leaves, and these of larvae were random on young leaves and concentrating on mature leaves, and these of larvae were random on young leaves and concentrating on mature leaves through all the stages. From these facts, it seems that the inter-leaves movement of larvae regulates their uneven distribution.