Commercial-scale field studies were conducted in citrus orchards to test the efficacy of entomopathogenic nematodes (EPNs) in controlling the soil-dwelling life stages of the key pest, . Trials were conducted in three provinces of South Africa from 2011 to 2013. Two EPN species were tested: and . Both EPN species were applied underneath citrus tree canopies, either with a spray machine or through the microsprinkler irrigation system. The concentration of nematodes and frequency of application varied. Efficacy of these treatments was measured by evaluation of EPN infection of sentinel larvae in the soil at various intervals after application and by infestation of fruit. Successful control was recorded in several trials, with EPN infection of larvae frequently reaching 80 %. However, in a few trials, this level of infection was assisted by naturally occurring EPNs. Fruit infestation by larvae was reduced by up to 88 %. Efficacy appeared to be limited by suboptimal soil moisture and temperature. The former was influenced mainly by mode and relative thoroughness of irrigation before and after EPN application. This was best obtained through microsprinkler application. Nematode species and concentration also influenced efficacy. Both EPN species survived and persisted in the soil of the treated orchards for up to 4 months. Promising results support their potential for use in an integrated pest management programme in citrus in South Africa.

中文翻译：

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南非柑橘园昆虫病原线虫对苹果蠹蛾（Thaumatotibia leucotreta）（鳞翅目：Tortricidae）的田间规模防治效果

在柑橘园进行了商业规模的田间研究，以测试昆虫病原线虫（EPN）在控制土壤栖息的关键害虫的生命阶段的功效。2011 年至 2013 年在南非的三个省份进行了试验。测试了两种 EPN 物种： 和 。两种 EPN 物种均通过喷雾机或微喷灌系统在柑橘树冠下施用。线虫的浓度和施用频率各不相同。这些处理的功效是通过评估施药后不同时间间隔土壤中哨兵幼虫的 EPN 感染以及果实的侵染情况来衡量的。多项试验均取得了成功控制，幼虫的 EPN 感染率经常达到 80%。然而，在一些试验中，自然发生的 EPN 有助于达到这种水平的感染。果树幼虫侵染减少高达 88%。功效似乎受到次优土壤湿度和温度的限制。前者主要受EPN施用前后灌溉方式和相对彻底性的影响。这最好通过微喷头应用来实​​现。线虫种类和浓度也影响功效。两种 EPN 物种均在经过处理的果园土壤中存活并持续长达 4 个月。令人鼓舞的结果支持了它们在南非柑橘害虫综合防治计划中的应用潜力。