桔小实蝇自然种群蛹和越冬成虫的耐寒性

本文通过过冷却点和低温耐寒能力的测定，研究了我国桔小实蝇Boctrocera dorsalis (Hendel)不同季节种群和地理种群蛹的耐寒性规律。结果表明：桔小实蝇自然种群蛹的低温存活力有明显的季节规律，冬前种群的耐寒性显著强于夏季种群。如在0℃低温下暴露2天，夏季种群基本全部死亡，而冬前种群存活率仍为61.4%。2005-2006年不同月份桔小实蝇1日龄蛹过冷却点差异明显，以2月份均值最高，为-9.26℃，8月份最低，为-15.20℃；且2月份桔小实蝇蛹个体过冷却点值出现明显的分化现象，分别在-15℃左右和-6℃左右出现两个明显的聚集区。所研究的5个桔小实蝇地理区域种群没有出现明显的耐寒性分化。结合本文结果，文中还就桔小实蝇自然种群耐寒性影响因素进行了讨论。

Cold hardiness of pupae and over-wintering adults from natural populations of Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) in China

In this study, cold hardiness of pupae and over-wintering adults among seasonal populations and geographic populations of Bactrocera dorsalis (Hendel) in China were assayed by measuring their supercooling capacity and cold survival ability. The results showed that cold tolerance of the pupa followed strong seasonal rhythm: the pre-winter population had higher tolerance to low temperature than the summer population; and the summer population completely collapsed as exposed to 0℃ for 2 days, but there was still 61.4% survivorship for the pre-winter population. The SCPs of one day-old pupae had significantly difference among the different months, highest in February (-9.26℃) while lowest in August (-15.20℃). Further analysis showed that there was a big variation range of SCPs among individuals, which were gathered around two points: -15℃ and -6℃. There was no significant difference in cold hardiness among five geographic populations of B. dorsalis. The main factors that influence cold hardiness of natural populations of B. dorsalis were discussed combined with the results obtained this study.