Agricultural Research Council-Institute for Tropical and Subtropical Crops, Private Bag X11208, Nelspruit 1200.
J Econ Entomol. 2010 Aug;103(4):1112-28. doi: 10.1603/ec09045.
Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) is pest of the avocado, Persea americana (Mill.) (Lauraceae), in South Africa and is regarded as a phytosanitary threat. The objective of this study was to develop a systems approach for T. leucotreta on 'Hass' avocado that will mitigate the pest risk. T. leucotreta males were monitored with pheromone traps, and numbers declined during the winter. Field studies indicated that most of eggs were laid during January in the Deerpark area, and during harvest, only 0.029 lesions produced live larvae. Survival of larvae in fruit infested on the tree and left to develop after harvest varied and depended on the time of infestation before harvest. Fruit firmness was measured and fifth instars were only present in soft fruit. Fenpropathrin and a granulovirus were effective in reducing the infestation levels. Bags used to cover fruit also reduced infestation levels. Lesions caused by T. leucotreta were visible from two weeks after infestation and fruit with lesions can be sorted. The mean infestation rate per orchard was 0.003 lesions per fruit which makes T. leucotreta on Hass amenable to the alternative treatment efficacy approach and maximum pest limit. In the case of T. leucotreta on Hass, poor host status, production, preharvest and postharvest measures were studied and low infestation levels were observed; all these elements would make a systems approach an option. Furthermore, inspection and certification as well as shipping and distribution measures could be added.
异色白腰实尾竹节虫 (Meyrick) (鳞翅目：卷叶蛾科) 是南非鳄梨（Persea americana (Mill.) (樟科) 的害虫，被视为植物检疫威胁。本研究的目的是为鳄梨 '哈斯' 制定一个针对 T. leucotreta 的系统方法，以减轻害虫风险。使用性信息素来监测 T. leucotreta 雄虫，数量在冬季下降。田间研究表明，大多数卵是在鹿园地区 1 月产的，在收获期间，只有 0.029 个损伤产生了活幼虫。在树上受感染并在收获后继续发育的幼虫的存活率各不相同，这取决于收获前的感染时间。测量了果实的硬度，只有在柔软的果实中才存在第五龄幼虫。虫螨腈和颗粒体病毒对降低感染水平有效。用于覆盖果实的袋子也降低了感染水平。感染 T. leucotreta 两周后可见损伤，可对带损伤的果实进行分拣。每个果园的平均感染率为每果 0.003 个损伤，这使得哈斯鳄梨上的 T. leucotreta 适合采用替代治疗效果方法和最大害虫限量。就哈斯鳄梨上的 T. leucotreta 而言，研究了不良的寄主状况、生产、收获前和收获后的措施，观察到低感染水平；所有这些因素都将使系统方法成为一种选择。此外，可以增加检查和认证以及运输和分销措施。
