Higaki Morio
Laboratory of Entomology, Department of Plant Protection, National Institute of Fruit Tree Science, Tsukuba, Ibaraki 305-8605, Japan.
J Insect Physiol. 2006 May;52(5):514-9. doi: 10.1016/j.jinsphys.2006.01.011. Epub 2006 Mar 20.
Curculio sikkimensis (Coleoptera: Curculionidae) requires one or more years to complete its life cycle, owing to prolonged larval diapause. To compare the effects of temperature cycles and total periods of chilling on the termination of prolonged diapause, larvae were subjected to different chilling (5 degrees C) and warming (20 degrees C) cycles ranging from 30 to 720 days, and all cycles were repeated until the sum of chilling and warming periods reached 720 days. The prolonged diapause of C. sikkimensis was more effectively terminated by repeated cycles of chilling and warming than by prolonging the continuous chilling period. However, extremely short temperature cycles were not highly effective in enhancing diapause termination, even when such cycles were repeated many times. To examine the role of warming periods on diapause termination, diapause larvae were subjected to a sequence of chilling (120 days at 5 degrees C) and warming (240 days at 20 degrees C) with a warming period (0-120 days at 20 degrees C) inserted in the chilling period. Diapause larvae that were not reactivated in the first chilling period required exposure to a certain period of warming before they were able to complete diapause development in the subsequent chilling. Thus, C. sikkimensis appears to spread its reactivation times over several years in response to seasonal temperature cycles.
锡金小蠹（鞘翅目：小蠹科）由于幼虫滞育期延长，需要一年或更长时间才能完成其生命周期。为了比较温度循环和冷藏总时长对延长滞育终止的影响，将幼虫置于不同的冷藏（5摄氏度）和升温（20摄氏度）循环中，时长从30天到720天不等，所有循环重复进行，直到冷藏和升温期的总和达到720天。与延长连续冷藏期相比，锡金小蠹的延长滞育通过反复的冷藏和升温循环能更有效地终止。然而，即使多次重复，极短的温度循环在促进滞育终止方面效果并不显著。为了研究升温期在滞育终止中的作用，将滞育幼虫置于一系列的冷藏（5摄氏度下120天）和升温（20摄氏度下240天）过程中，在冷藏期插入一个升温期（20摄氏度下0至120天）。在第一个冷藏期未被重新激活的滞育幼虫，需要经历一定时长的升温，才能在随后的冷藏中完成滞育发育。因此，锡金小蠹似乎会根据季节性温度循环，将其重新激活时间分散在数年之中。
