Chown S L., Jaco Klok C
Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
J Insect Physiol. 1997 Jul;43(7):685-694. doi: 10.1016/s0022-1910(97)00001-2.
Thermal tolerance, supercooling point, water balance and osmoregulatory ability of Pringleophaga marioni Viette (Lepidoptera: Tineidae) are investigated in this study. Field-fresh larvae had a mean CT(Min) (cold stupor) of -0.6 degrees C and a mean CT(Max) (heat coma) of 38.7 degrees C. The mean supercooling point of field-fresh individuals was -5.0 degrees C. Caterpillars showed 100% survival of freezing to -6.5 degrees C, but at -12 degrees C mortality rose to 100%. Survival of a 30h exposure to -6.0 degrees C was 80%, but declined to 30% in the 6-12h interval at -7.5 degrees C. No caterpillars survived for longer than 12h at -9.0 degrees C. Survival of high temperatures (35 degrees C and above) was poor. Tolerance of water loss (46% of fresh mass) and rates of water loss (1% fresh massh(-1)) were similar to those found in other mesic insects. P. marioni larvae were incapable of metabolizing lipids to replenish lost water and showed no haemolymph osmoregulatory ability. It is suggested that the preponderance of freeze tolerance in high-latitude southern hemisphere species may be associated with their occurrence in moist habitats, and that the "freeze tolerance" category be re-examined in the light of the range of strategies adopted by such arthropods.
本研究调查了马里昂普氏蛾（Pringleophaga marioni Viette，鳞翅目：麦蛾科）的耐热性、过冷却点、水分平衡和渗透调节能力。野外新鲜幼虫的平均低温昏迷温度（CT(Min)）为-0.6摄氏度，平均高温昏迷温度（CT(Max)）为38.7摄氏度。野外新鲜个体的平均过冷却点为-5.0摄氏度。毛虫在-6.5摄氏度冷冻时存活率为100%，但在-12摄氏度时死亡率升至100%。在-6.0摄氏度暴露30小时的存活率为80%，但在-7.5摄氏度的6至12小时间隔内降至30%。在-9.0摄氏度时，没有毛虫存活超过12小时。高温（35摄氏度及以上）下的存活率很低。水分损失耐受性（新鲜质量的46%）和水分损失率（1%新鲜质量·小时⁻¹）与其他中生昆虫相似。马里昂普氏蛾幼虫无法代谢脂质来补充失去的水分，且没有血淋巴渗透调节能力。研究表明，高纬度南半球物种中耐寒性占优势可能与其在潮湿生境中的出现有关，并且鉴于此类节肢动物所采用的一系列策略，应重新审视“耐寒性”类别。
