THE INFLUENCE OF FOOD UPON THE NUTRITION OF INSECTS

The present experiment was undertaken to find the relation between the nutrition of insects and the kind of leaves they use for food. Dictyoploca Japonica, commonly called \u22Kususan or Shiragataro,\u22 is common in Japan. It lives mainly on various leaves, such as those of the ginkgo, poplar, walnut, beech, oak, chestnut, camphor, lacquer, etc. The author has investigated the nutritive value of plant leaves, such as poplar camphor and ginkgo. There is maked difference between them, poplar leaves being the most nutritive, camphor leaves second, and ginkgo leaves third in nutritive value. When the insect is fed on poplar leaves, its larval growth is most rapid, its body weight and its production of silk matter and eggs is greatest; and the content of glycogen and fat in its body is richest. When fed on camphor leaves, the conditions of growth and nutrition are ordinary. When fed on ginkgo leaves, they are poor. The author came to the conclusion that such difference in the nutritive value of leaves is caused chiefly by the difference in their content of nitrogenous matter.多食性昆蟲が食餌植物を異にして生長する場合, その植物の相異が昆蟲の榮養上如何なる關係あるかは昆蟲生理學上甚だ興味ある問題なり。從來樟蠶の食餌植物として知られたるものに, いてふ(Ginkgo biloba), ポプラ(Populus nigra), くるみ(Jugalaus sieboldiana), かしは(Quercus deutata),あかがし(Quercus acuta), くぬぎ(Quercus acutissua), くり(Castanea sativa), くす(Cinnamomum camphora), うるし(Rhus vernicifera), ぬるで(Rhus semi-alata), とちのき(Aesculus turbinata), ひやくぢつこう(Lagerstraemia intica), 等あり。以上のうち北九州に於て最も普通なるはポプラ, 樟及び公孫樹の三種なり。著者は昭和五年これら植物に寄生せる樟蠶を採集し, その發育經過の状態を觀察し, 絹質物生産最を比較し, 産卵量を調査し更に進んで食餌植物葉の化學組成と蛹體の化學組成とを比較研究せり。爰にその收め得たる結果の大要を報告せんとす