Malod et al. Insect Science.xlsx

Knowing how environmental conditions affect performance traits in pest insects is important to improve pest management strategies. It can be informative for monitoring, but also for control programmes where insects are mass-reared, and field-released. Here, we investigated how adult thermal acclimation in sterile <i>Bactrocera dorsalis</i> affects dispersal and recapture rates in the field using a mark-release-recapture method. We also considered how current abiotic factors may affect recapture rates and interact with thermal history. We found that acclimation at 20 or 30ºC for four days prior to release reduced the number of recaptures in comparison with the 25ºC control group, but with no differences between groups in the willingness to disperse upon release. However, the deleterious effects of acclimation were only detectable in the first week following release, whereafter only the recent abiotic conditions explained recapture rates. In addition, we found that recent field conditions contributed more than thermal history to explain patterns of recaptures. The two most important variables affecting the number of recaptures were the maximum temperature and the average relative humidity experienced in the 24 hours preceding trapping. Our results add to the handful of studies that have considered the effect of thermal acclimation on insect field performance, but notably lend support to the deleterious acclimation hypothesis among the various hypotheses that have been proposed. Finally, this study shows that there are specific abiotic conditions (cold/hot and dry) in which recaptures will be reduced, which may therefore bias estimates of wild population size.

探明环境条件对害虫性能性状的影响规律，对于优化害虫防治管理策略具有重要意义。该研究不仅可为害虫监测提供理论参考，也可指导昆虫大规模饲养与野外释放类防治项目的开展。本研究采用标记释放再捕获法，探究了不育橘小实蝇（Bactrocera dorsalis）成虫的热驯化对其野外扩散能力与再捕获率的影响，同时分析了当前非生物因子对再捕获率的作用及其与热驯化历史的交互效应。研究结果显示：相较于25℃对照组，释放前经20℃或30℃热驯化4天的试虫，其野外再捕获数量显著降低，但各组成虫释放后的扩散意愿无显著差异。不过，热驯化的不利效应仅在释放后的第一周可被检测到，此后再捕获率仅受近期非生物环境条件的影响。此外，本研究发现，相较于热驯化历史，近期野外环境条件对再捕获模式的解释度更高。影响再捕获数量的两个核心变量为诱捕前24小时内的最高气温与平均相对湿度。本研究结果补充了少量探讨热驯化对昆虫野外性能影响的相关研究，尤为重要的是，其为已提出的各类假说中的不利驯化假说提供了实证支持。最后，本研究表明，在特定非生物环境条件（低温/高温与干旱环境）下，害虫再捕获率会降低，这可能会对野生种群规模的估算造成偏差。