Hua Ai, Yang Dong, Wu Shaohui, Xue Fangsen
Institute of Entomology, Jiangxi Agricultural University, Nanchang 330045, PR China.
J Insect Physiol. 2005 Nov;51(11):1261-7. doi: 10.1016/j.jinsphys.2005.07.004. Epub 2005 Aug 31.
In the zygaenid moth, Pseudopidorus fasciata, both larval diapause induction and termination are under photoperiodic control. In this study, we investigated whether photoperiodic time measurement (with a 24-h light-dark cycle) in this moth is qualitative or quantitative. Photoperiodic response curves, at 22, 25, and 28 degrees C indicated that the incidence of diapause depended on whether the scotophases exceeded the critical night length (CNL) or not. All scotophases longer than the CNL-induced diapause; all scotophases shorter than the CNL-inhibited diapause. The CNL was 10.5h at 25 and 28 degrees C, and 10h at 22 degrees C. By transferring from various short photoperiods (LD 8:16, LD 9:15, LD 10:14, LD 11:13, LD 12:12, and LD 13:11) to a long photoperiod (LD 16:8) at different times, the number of light-dark cycles required for 50% diapause induction at 25 degrees C was 7.14 at LD 8:16, 7.2 at LD 9:15, 7.19 at LD 10:14, 7.16 at LD 11:13, and 7.13 at LD 12:12, without showing a significant difference between the treatments. Only at LD 13:11 (near the CNL), the number of light-dark cycles was significantly increased to 7.64. The intensity of diapause induced under different short photoperiods (LD 8:16, LD 9:15, LD 10:14, LD 11:13, and LD 12:12) at 25 degrees C was not significantly different with an average diapause duration of 36 days. The duration of diapause induced under LD 13:11 was significantly reduced to 32 days. All results indicate that the night-lengths are measured as either "long" or "short" compared with some critical value and suggest that photoperiodic time measurement for diapause induction in this moth is based on a qualitative principle.
在透翅蛾科蛾类昆虫黄斑拟透翅蛾（Pseudopidorus fasciata）中，幼虫滞育的诱导和终止均受光周期控制。在本研究中，我们调查了这种蛾类昆虫（在24小时明暗周期下）的光周期时间测量是定性的还是定量的。在22℃、25℃和28℃下的光周期反应曲线表明，滞育的发生率取决于暗期是否超过临界夜长（CNL）。所有长于CNL的暗期都会诱导滞育；所有短于CNL的暗期都会抑制滞育。在25℃和28℃时，CNL为10.5小时，在22℃时为10小时。通过在不同时间从各种短光周期（LD 8:16、LD 9:15、LD 10:14、LD 11:13、LD 12:12和LD 13:11）转移到长光周期（LD 16:8），在25℃下诱导50%滞育所需的明暗周期数在LD 8:16时为7.14，在LD 9:15时为7.2，在LD 10:14时为L7.19，在LD 11:13时为7.16，在LD 12:12时为7.13，各处理之间无显著差异。仅在LD 13:11（接近CNL）时，明暗周期数显著增加至7.64。在25℃下，不同短光周期（LD 8:16、LD 9:15、LD 10:14、LD 11:13和LD 12:12）诱导的滞育强度无显著差异，平均滞育持续时间为36天。在LD 13:11下诱导的滞育持续时间显著缩短至32天。所有结果表明，与某个临界值相比，夜长被测量为“长”或“短”，这表明这种蛾类昆虫滞育诱导的光周期时间测量基于定性原则。
