Khani Abbas, Moharramipour Saeid
Department of Entomology, College of Agriculture, Tarbiat Modares University, P.O. Box 14115-336, Tehran, Iran.
Pak J Biol Sci. 2007 Aug 1;10(15):2591-4. doi: 10.3923/pjbs.2007.2591.2594.
To elucidate the relationship between diapause and cold hardiness, seasonal variations of supercooling point and low temperature survival of overwintering and non-diapausing larvae of codling moth were studied in two regions of Iran, Damavand and Karaj. In both regions supercooling point decreased gradually over the autumn. Supercooling point of field collected larvae in Damavand reduced from a mean value of -16.9 degrees C in early September to -19.9 degrees C in mid-October 2004. At the same time, supercooling point of overwintering larvae decreased from -19 to -21 degrees C in Karaj. Supercooling point decreased gradually until midwinter (January) in both regions and afterward increased gradually over the spring. Mean supercooling point for non-diapausing larvae was -13.4 degrees C, which was significantly higher than that of overwintering larvae. A high coincidence was observed between decrease of supercooling point and increase of low temperature survival rate in the overwintering larvae. Survival rate at -20 degrees C/24 h was lower than 20% in early autumn; that increased to upper than 50% during winter. Codling moth was shown to be a freeze susceptible and at the same time, a chill tolerant insect.
为阐明滞育与耐寒性之间的关系，在伊朗的达马万德和卡拉季两个地区研究了苹果蠹蛾越冬幼虫和非滞育幼虫的过冷却点及低温存活率的季节变化。在这两个地区，过冷却点在秋季均逐渐降低。2004年9月初，达马万德野外采集幼虫的过冷却点平均值为-16.9℃，到10月中旬降至-19.9℃。与此同时，卡拉季越冬幼虫的过冷却点从-19℃降至-21℃。在这两个地区，过冷却点一直持续降低至冬季中期（1月），随后在春季逐渐升高。非滞育幼虫的平均过冷却点为-13.4℃，显著高于越冬幼虫。在越冬幼虫中，过冷却点的降低与低温存活率的增加之间存在高度一致性。在初秋，-20℃/24小时条件下的存活率低于20%；在冬季则增至50%以上。研究表明苹果蠹蛾是一种易受冻害但同时又耐冷的昆虫。
