False codling moth Thaumatotibia leucotreta （Lepidoptera, Tortricidae） larvae are chill-susceptible

作     者：Leigh Boardman Tim G. Grout John S. Terblanche 

作者机构：Department of Conservation Ecology and Entomology Faculty of Agrisciences Stellenbosch University Stellenbosch South Africa Citrus Research International Nelspruit South Africa 

出 版 物：《Insect Science》 (昆虫科学（英文版）)

年 卷 期：2012年第19卷第3期

页      面：315-328页

核心收录：

学科分类：0710[理学-生物学] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 09[农学] 0904[农学-植物保护] 0901[农学-作物学] 090401[农学-植物病理学] 090402[农学-农业昆虫与害虫防治] 0713[理学-生态学] 

基　　金：supported by Citrus Research International (Primary Investigator [PI]: TGG) DFPT funding (PI: JST) NRF-THRIP (PI: Dr. P. Addison) 

主　　题：behavior chill injury cold hardiness disinfestations extracellular freezing,lethal limits life-stage 

摘      要：This study reports on the low temperature tolerance and cold hardiness of larvae of false codling moth, Thaumatotibia leucotreta. We found that larvae have mean critical thermal minima （lower limits of activity） of 6.7℃ which was influenced by feeding status. The effects of low temperature exposure and duration of exposure on larval survival were assessed and showed that the temperature at which 50% of the population survives is -11.5 ± 0.3℃ after 2 h exposure. The supercooling point （SCP, i.e., freezing temperature） was investigated using a range of cooling rates and under different conditions （feeding and hydration status） and using inoculative freezing treatments （in contact with water or orange juice）. The SCP decreased significantly from -15.6℃ to -17.4℃ after larvae were fasted for 24 h. Twenty-four hour treatments at either high or low relative humidity （95.9% or 2.4%） also significantly decreased SCP to -17.2℃ and -18.2℃ respectively. Inoculative freezing （by water contact） raised SCP from -15.6℃ to -6.8℃ which could have important implications for post-harvest sterilization. Cooling rates did not affect SCP which suggests that there is limited phenotypic plasticity of SCP during the larval life-stage, at least over the short time-scales investigated here. In conclusion, larvae of T. leucotreta are chill-susceptible and die upon freezing. These results are important in understanding this pest＇s response to temperature variation, understanding pest risk status and improving post-harvest sterilization efficacy