Influence of Light and Dark Environments on the Oviposition of Drosophila virilis

• Published in: Environment Control in Biology Vol. 10; no. 4; pp. 187 - 191
• Main Authors: OSHIMA, Chozo, INOUE, Koichi, ISHIWA, Sadao
• Format: Journal Article
• Language: English
• Published: Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists 1972
• ISSN: 0582-4087; 2185-1018
• DOI: 10.2525/ecb1963.10.4_187

(1) An experimental population of Drosophila virilis was established by the progeny of flies collected at Azumabashi in Tokyo. Twelve iso-female strains were extracted from it. Then, 9 sib-mating lines were made from each strain and they were divided into three groups. One group was composed of 36 sib-mating lines which were female and male pair matings. Three groups were cultured under three kinds of light environments as follows; constant light, periodical light and dark (9L, 3L→D, 9D, 3D→L) and dark with short light (15 min) . Flies were transferred into new vials every day, and eggs laid during 24 hours on the culture medium were scored. Such experimental procedures of three groups were continued simultaneously for 10 days under constant 25°C. (2) The total number of eggs laid under dark with short light environment was the most and that under periodical light and dark environment was the middle and that under constant light was the least. However, the difference between total numbers of eggs laid for the former 5 days and the latter 5 days was noticed. Under either constant light or dark with short light environments, the difference was about 20 eggs a day, but under periodical light and dark environment, the difference was only 6 eggs a day. From the result, the former two light environments are assumed to be bad for maintaining the regular biorhythm of oviposition and the periodical light and dark environment would be good for it. (3) The oviposition was remarkably influenced by light environments and it would be accelerated with the short light in the long dark. Female flies, which laid a great number of eggs or very few eggs under a light environment, could not be found among 12 iso-female strains. Some female flies of several strains were short-lived under non-periodical light environments. The total numbers of eggs of 12 strains under three kinds of light environments were arranged in order and the order was preserved significantly under any light environments.