Photoperiodic control of diapause induction was investigated in the short-day species, Colaphellus bowringi, which enters summer and winter diapause as adult in the soil. Photoperiodic responses at 25 and 28▫C revealed a critical night length between 10 and 12 h; night lengths ≥12 h prevented diapause, whereas night lengths <12 h induced summer diapause in different degree. Experiments using non-24-h light–dark cycles showed that the duration of scotophase played an essential role in the determination of diapause. Night-interruption experiments with T=24 h showed that diapause was effectively induced by a 2-h light pulse in most scotophases; whereas day-interruption experiments by a 2-h dark break had a little effect on the incidence of diapause. The experiments of alternating short-night cycles (LD 16:8) and long-night cycles (LD 12:12) during the sensitive larval period showed that the information of short nights as well as long nights could be accumulated. Nanda–Hamner experiments showed three declining peaks of diapause at 24 h circadian intervals. Bünsow experiments showed two very weak peaks for diapause induction, one being 8 h after lights-off, and another 8 h before lights-on, but it did not show peaks of diapause at a 24 h interval. These results suggest that the circadian oscillatory system constitutes a part of the photoperiodic clock of this beetle but plays a limited role in its photoperiodic time measurement.

大猿叶虫Colaphellus bowringi是江西山区十字花科蔬菜上的重要食叶害虫，以成虫在土中越夏和越冬。由于成虫滞育期的差异，该虫的化性显示了明显的种内变异。有些个体隔年繁殖；有些个体是一化性的，仅在春季或秋季繁殖1代；有些个体是二化性的，春季和秋季各繁殖1代；有些个体是多化性的，春季1代，秋季2～3代。因此，大猿叶虫在田间一年可发生4代。在春季，滞育成虫于2月底至4月初陆续出土繁殖；在秋季，滞育成虫于8月中旬至10月初陆续出土繁殖。春季羽化的成虫于4月底至6月上旬陆续入土越夏，秋季羽化的成虫于9月中旬至12月底陆续入土越冬。大猿叶虫一生能交配多次，大多数雌虫的产卵期超过1个月，最长达67天。平均每雌产卵量；春季世代为644粒，秋季世代为963粒，最高达1950粒。各虫态的发育历期：在15～30℃间，卵为13.78～3.14天，幼虫为22.83～6.95天，蛹为12.10～3.18天。发育阈值温度：卵为10.7 ℃，幼虫为8.8 ℃，蛹为9.6 ℃。非滞育成虫的寿命约为1～2个月，滞育成虫的寿命为5～38个月。滞育成虫均入土蛰伏，在土中的蛰伏深度为9～31cm。

Dendrolimus tabulaeformis overwinters as third to fourth instar larvae at short days in autumn. Using 24-h light–dark cycles, the photoperiodic response curves were similar at 24 and 28▫C. The critical night length was 9 h 20 min at 24▫C and 9 h 50 min at 28▫C. Under non-24 h light–dark cycles, duration of scotophase proved crucial in the determination of diapause. In night interruption experiments using 24-h light–dark cycle, a 1-h light pulse falling 8 h in the darkness strongly averted diapause in comparison with other light pulses. Nanda–Hamner experiments showed two weak troughs of diapause inhibition, suggesting the possible involvement of the circadian system. However, Bünsow experiments did not support the evidence of the involvement of circadian oscillatory system in photoperiodic time measurement. These results suggest that photoperiodic time measurement in this moth shows a non-oscillatory ‘hourglass-like’ response model or a rapidly damping oscillator model.

On the southern Iberian Peninsula, the seasonal life history of the large white butterfly, Pieris brassicae, comprises 2 different photoperiodically induced developmental arrests: a hibernation diapause at photophases <11 h and an estivation diapause at photophases >14 h. At intermediate photophases (12 h to 13 h), the butterfly responds with a nondiapause. Combined with the experimental setup to determine photosensitivity in insects, the different photoperiodic responses at long-, intermediate-, and short-night conditions were examined to gain more insight into the time measurement mechanism in P. brassicae. The study reveals evidence for a “double circadian oscillator clock” mechanism that is based on 2 submechanisms, a “short-night determining system” and a separate “long-night determining system.” This conclusion was drawn from the facts that an LD 9:15 long-night induces a hibernation diapause but inhibits an estivation diapause and, conversely, that an LD 16:8 short-night inhibits a hibernation diapause but induces an estivation diapause. This opposite effect of the same photoperiod supports the argument for the existence of 2 independent targets for light-dark cycles, interpreted as 2 antagonistic time measurement systems. The existence and independence of 2 systems was further shown by differences in long-night versus short-night responses regarding photosensitivity, temperature dependence, and heritable factors. The long-night measurement system is most effective in the 5th larval stage, is highly affected by temperature, and is easy to manipulate by selective inbreeding. The short-night measurement system is most effective in the 4th larval stage, is largely temperature compensated, and is not affected by experimental manipulation of the longnight measurement system.

大猿叶虫Colaphellus bowringi Baly是我国十字花科蔬菜上的一种重要害虫，以成虫在土壤中越冬和越夏，滞育发生主要受温度和光周期调节。本文就光周期和温度对滞育后成虫生物学特性的影响进行了研究。结果表明，在25℃下，光周期(L14: D10和L12: D12)对成虫滞育后的存活率、寿命、日平均产卵量、总产卵量均无显著影响。在长光照(L14: D10)下，温度(18℃、22℃和25℃)对滞育后成虫的生物学特性具有明显的影响；随温度的降低，总产卵量呈下降趋势，平均产卵量显著降低，雌虫滞育后寿命显著延长，18℃下少数个体能被诱导再次滞育。