Moore S D, Kirkman W, Hattingh V
Citrus Research International, PO Box 20285, Humewood 6013, Port Elizabeth, South Africa (
Citrus Research International, Department of Horticultural Sciences, Stellenbosch University, Victoria Street, Stellenbosch 7602, South Africa (
J Econ Entomol. 2016 Aug;109(4):1564-70. doi: 10.1093/jee/tow139. Epub 2016 Jun 24.
A systems approach has been developed for mitigation of risk associated with Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), in citrus fruit exported from South Africa, as an alternative to a stand-alone cold treatment. This study was undertaken to assess compliance with inspection standards applicable to various steps within the systems approach and to determine its overall efficacy. Larval infestation of fruit was monitored weekly in fruit from 33 orchards, until the time of harvest, postpicking, and postpacking into export cartons. Significant positive regressions were recorded between infestation of fruit during the full monitoring period in the orchard and the last 4 wk before harvest, between the last 4 wk before harvest and on delivery to the packinghouse, and on delivery to the packinghouse and in the packed carton. There was an improvement in the level of compliance with each of these successive steps in the system, thus verifying that the grading and inspection thresholds were appropriately sensitive and confirmed the effectiveness of the system. The overall risk mitigation efficacy of the systems approach was calculated. The calculation included several known compounding under estimations of efficacy. Nonetheless, the proportion of fruit that could be infested with T. leucotreta after application of the systems approach was between P ≤ 5.328 × 10(-6) and P ≤ 8.380 × 10(-7), 6-38 times less than the proportion associated with the probit 9 (P ≤ 3.2 × 10(-5)) standard for a stand-alone cold treatment, being three survivors in 100,000 at the 95% confidence level.
已开发出一种系统方法，用于降低南非出口柑橘类水果中与白小食心虫（Thaumatotibia leucotreta (Meyrick)，鳞翅目：卷蛾科）相关的风险，作为单独冷藏处理的替代方法。本研究旨在评估该系统方法内各个步骤对适用检查标准的符合情况，并确定其总体效果。在33个果园的果实中每周监测幼虫侵染情况，直至收获、采后以及装入出口纸箱后的阶段。在果园整个监测期内果实的侵染情况与收获前最后4周、收获前最后4周与运至包装厂时、运至包装厂时与装入纸箱后的果实侵染情况之间，均记录到显著的正相关关系。该系统中这些连续步骤的符合水平均有提高，从而验证了分级和检查阈值具有适当的敏感性，并证实了该系统的有效性。计算了该系统方法的总体风险降低效果。该计算包括了几个已知的对效果估计不足的复合因素。尽管如此，应用该系统方法后可能被白小食心虫侵染的果实比例在P≤5.328×10⁻⁶至P≤8.380×10⁻⁷之间，比单独冷藏处理的概率9（P≤3.2×10⁻⁵）标准相关比例少6 - 38倍，即在95%置信水平下每100,000个中有三个存活个体。
