Liu Tao, Li Li, Li Baishu, Zhan Guoping, Wang Yuejin
Institute of Equipment Technology, Chinese Academy of Inspection and Quarantine, Beijing, P.R. China.
J Econ Entomol. 2018 May 28;111(3):1165-1170. doi: 10.1093/jee/toy029.
Oriental fruit fly, Bactrocera dorsalis (Hendel; Diptera: Tephritidae), is recognized as a quarantine pest and a threat to Chinese loquat (Eriobotrya japonica Lindl.) fruit exports. Since loquat fruit is very sensitive to methyl bromide (MB) fumigation and cold treatment, in this study, low-temperature phosphine (PH3) fumigation was investigated to develop an alternative phytosanitary treatment method. Tolerance tests showed that the third instar was the most tolerant of all life stages of B dorsalis to PH3 gas at 8°C. Toxicity assay with 500-3000 ppm PH3 and subsequent probit analysis showed that 2000 ppm PH3 was optimal for fumigation and 152.75 h of treatment duration were required to achieve 99.9968% mortality. In the verification test, 144 and 168 h of treatment duration with 2000 ppm PH3 completely killed 35,277 and 35,134 B. dorsalis third instars, respectively. However, 13 live larvae were found after 120 h of treatment. Furthermore, these treatments reduced fruit respiration rates while causing no adverse effects on other fruit quality parameters, including firmness, soluble solid content, and titratable acidity over 192 h storage at 8°C. The results strongly suggest that low-temperature PH3 fumigation could be used for the postharvest control of B. dorsalis in loquat fruit.
东方果实蝇，即橘小实蝇（亨德尔；双翅目：实蝇科），被视为一种检疫性害虫，对中国枇杷（枇杷属枇杷种）水果出口构成威胁。由于枇杷果实对溴甲烷熏蒸和冷藏处理非常敏感，在本研究中，对低温磷化氢熏蒸进行了研究，以开发一种替代的植物检疫处理方法。耐受性试验表明，在8°C条件下，三龄幼虫是橘小实蝇所有生命阶段中对磷化氢气体耐受性最强的。用500 - 3000 ppm磷化氢进行毒性测定并随后进行概率分析表明，2000 ppm磷化氢是熏蒸的最佳浓度，需要152.75小时的处理时间才能达到99.9968%的死亡率。在验证试验中，用2000 ppm磷化氢处理144小时和168小时分别完全杀死了35277头和35134头橘小实蝇三龄幼虫。然而，处理120小时后发现有13头活幼虫。此外，这些处理降低了果实的呼吸速率，同时在8°C下储存192小时期间，对包括硬度、可溶性固形物含量和可滴定酸度在内的其他果实品质参数没有产生不利影响。结果有力地表明，低温磷化氢熏蒸可用于枇杷果实采后对橘小实蝇的防治。
