In this study, we examined the effects of photoperiod and light intensity on the regulation of colony development in Lasius japonicus Santschi. Queens were collected soon after their nuptial flight in Okayama City, Japan and reared in the laboratory. In the first experimental series, insects were reared under 14L10D(14 hours light 10 hours dark), 13L11D, 12L12D, 11L13D, and 10L14D at 20°C to examine the effects of photoperiod on colony development. In the second experimental series, the insects were maintained under either of the two light intensity conditions, i.e., 3,000 or 30 lx, under 12L12D at 25°C. The eggs, larvae, and pupae were counted daily. No significant differences among photoperiods were detected in the number of eggs, larvae, and pupae, indicating that photoperiod does not play a considerable role in the seasonal regulation of colony development. Under the 3,000 lx condition, larvae and pupae did not emerge in most of the colonies, although queens continued ovipositing throughout the experimental periods. It was considered that queens eat eggs or first-instar larvae.
抄録全体を表示