Moore Sean D, Kirkman Wayne, Peyper Mellissa, Thackeray Sean R, Marsberg Tamryn, Albertyn Sonnica, Hill Martin P
Citrus Research International, Humewood, Port Elizabeth, South Africa.
Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa.
J Econ Entomol. 2018 Dec 14;111(6):2637-2643. doi: 10.1093/jee/toy287.
The litchi moth, Cryptophlebia peltastica (Meyrick) (Lepidoptera: Tortricidae), is endemic to sub-Saharan Africa and certain Indian Ocean islands. It is an important pest of litchis and to a lesser extent macadamias. Litchis are exported to certain markets that consider C. peltastica as a phytosanitary pest. Consequently, an effective postharvest phytosanitary treatment is required. This study sought to develop a cold disinfestation treatment for this purpose. First, it was established that the fifth instar was the most cold-tolerant larval stage, as it was the only instar for which there was still some survival after 12 d at 1°C. It was then determined that cold treatment trials could be conducted in artificial diet, as there was no survival of fifth instar C. peltastica in litchis after only 9 d at 1°C, whereas it took 15 d at this temperature before no survival of fifth instar C. peltastica was recorded in artificial diet. Consequently, cold susceptibility of fifth instar C. peltastica and the most cold-tolerant larval stages (fourth and fifth instar) of false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), were compared in artificial diet. There was no survival of C. peltastica after 13 d at 1°C, whereas this was only so for T. leucotreta after 16 d. Consequently, it can be concluded that any cold treatment that has been proven effective against T. leucotreta would be as effective against C. peltastica. Finally, it was confirmed that the cold susceptibility of T. leucotreta in artificial diet did not overestimate the effect of cold on T. leucotreta larvae in litchis.
荔枝细蛾（Cryptophlebia peltastica (Meyrick)，鳞翅目：卷蛾科）原产于撒哈拉以南非洲和某些印度洋岛屿。它是荔枝的一种重要害虫，对澳洲坚果的危害较小。荔枝出口到某些将荔枝细蛾视为植物检疫性害虫的市场。因此，需要一种有效的采后植物检疫处理方法。本研究旨在为此开发一种冷处理除害方法。首先，确定五龄幼虫是最耐寒的幼虫阶段，因为它是在1°C下放置12天后仍有部分存活的唯一虫龄。然后确定可以在人工饲料中进行冷处理试验，因为在1°C下，五龄荔枝细蛾在荔枝中仅9天后就没有存活个体，而在人工饲料中，在该温度下15天后才没有记录到五龄荔枝细蛾存活个体。因此，在人工饲料中比较了五龄荔枝细蛾和荔枝异形小卷蛾（Thaumatotibia leucotreta (Meyrick)，鳞翅目：卷蛾科）最耐寒的幼虫阶段（四龄和五龄）对低温的敏感性。荔枝细蛾在1°C下放置13天后没有存活个体，而荔枝异形小卷蛾在16天后才如此。因此，可以得出结论，任何已被证明对荔枝异形小卷蛾有效的冷处理对荔枝细蛾也同样有效。最后，证实了人工饲料中荔枝异形小卷蛾对低温的敏感性并没有高估低温对荔枝中荔枝异形小卷蛾幼虫的影响。
