Graduate School of Horticulture, Chiba University, Matsudo 648, Matsudo, Chiba, Japan.
J Insect Physiol. 2011 Sep;57(9):1185-9. doi: 10.1016/j.jinsphys.2011.05.018. Epub 2011 Jun 14.
The inhibitory effects of the timing, intensity (I(I)) and period (I(T)) of night-interrupting light on diapause induction of the Kanzawa spider mite (Tetranychus kanzawai) were investigated in a series of laboratory experiments. During a light and dark period of 8 and 16 h d(-1), respectively, a single 1-h night-interrupting light was applied at early (E), middle (M), and late (L) parts of the dark period: i.e., at 3, 7.5, and 12h after the start of the dark period, respectively. No interrupting light was applied in the control treatment. The incidence of diapause was significantly lower in the M treatment (63%) compared to the control treatment (100%). In the E and L treatments, more than 90% of females entered diapause, which was comparable to the control treatment. Since the longest consecutive dark period during the E and L treatments was longer than the critical dark period (CDP) of 10.5-11 hd(-1), during which 50% of females entered diapause, the night-interrupting light probably failed to prevent diapause induction. However, in the M treatment, the longest consecutive dark period was shorter than the CDP; therefore, the night-interrupting light inhibited diapause induction. Moreover, the inhibitory effects of night-interrupting light in the M treatment increased as I(I) and I(T) increased. The dose of night-interrupting light (I(I)×I(T)) was significantly negatively related to the incidence of diapause. The median effective dose for 50% disturbance of diapause induction was 2.5 kJ m(-2) at wavelengths between 350 and 1050 nm. Our results suggest that the longest consecutive dark period and the dose of night-interrupting light should both be considered when a lighting-based physical control is applied to inhibit diapause induction and consequent overwintering of T. kanzawai in commercial agricultural fields.
本研究在一系列实验室实验中，调查了夜间中断光的时间、强度（I(I))和周期（I(T))对卡赞瓦蜘蛛螨（Tetranychus kanzawai)滞育诱导的抑制作用。在光暗周期分别为 8 和 16 h d(-1)的情况下，在暗期的早期（E）、中期（M）和晚期（L）部分各施加 1 小时的单次夜间中断光：即在暗期开始后 3、7.5 和 12 h 分别施加。在对照处理中没有施加中断光。与对照处理（100%)相比，M 处理（63%)中滞育的发生率显著降低。在 E 和 L 处理中，超过 90%的雌性进入滞育，与对照处理相当。由于 E 和 L 处理中最长的连续暗期长于临界暗期（CDP）10.5-11 h d(-1)，在此期间有 50%的雌性进入滞育，因此夜间中断光可能无法阻止滞育的诱导。然而，在 M 处理中，最长的连续暗期短于 CDP；因此，夜间中断光抑制了滞育的诱导。此外，随着 I(I)和 I(T)的增加，M 处理中夜间中断光的抑制作用增强。夜间中断光的剂量（I(I)×I(T))与滞育发生率呈显著负相关。波长在 350 到 1050nm 之间，干扰 50%滞育诱导的中效剂量为 2.5 kJ m(-2)。我们的研究结果表明，在商业农业领域应用基于光照的物理控制来抑制 T.kanzawai 滞育诱导和随后的越冬时，应同时考虑最长连续暗期和夜间中断光的剂量。
