ABSTRACT

In Colombia, the Tetranychus urticae mite (Acari: Tetranychidae) is one of the most challenging phytosanitary issues faced by flower cultivators. The control of this mite has been commonly done through the use of chemical insecticides. But the mites have generated resistance to these substances over time, making their handling more difficult. Some sustainable alternatives based on the use of biological control agents (BCA) can also be implemented in the control of T. urticae. The fungus Akanthomyces lecanii has proved to be effective in the control of T. urticae, however, is conventionally produced by solid-state fermentation (SSF) with low yields and high costs. Submerged fermentation (SmF) is a successful alternative that increases yields and reduces times in BCA production. In this research, the conditions for the production of A. lecanii by SmF were determined to improve the control of T. urticae in the Gerbera jamesonii. The percentage of immobile T. urticae adults, and the median lethal time (LT₅₀) values, were evaluated. Also, some low molecular weight compounds were extracted and detected by liquid chromatography coupled with high-resolution mass spectrometry. The concentration of A. lecanii produced in SmF was 132 times higher than that obtained from SSF and, better control of mite populations was observed both in vitro and in the field. These results show that the production of A. lecanii by SmF can be a more efficient alternative to implement comprehensive control strategies in flower crops.

摘要

在哥伦比亚，荨麻叶螨（Acari：Tetranychidae）是花卉栽培者面临的最具挑战性的植物检疫问题之一。这种螨的控制通常是通过使用化学杀虫剂来完成的。但随着时间的推移，螨虫对这些物质产生了抵抗力，这使得它们的处理变得更加困难。一些基于使用生物控制剂 (BCA) 的可持续替代方法也可以用于控制荨麻疹。真菌枝菌三级Akanthomyces已被证明是有效的控制T.螨然而，传统上通过固态发酵（SSF）生产，产量低，成本高。深层发酵 (SmF) 是一种成功的替代方法，可提高产量并缩短 BCA 生产时间。在这项研究中，对于生产条件A.枝菌三级确定由SMF是改进的控制T.螨的非洲菊。评估了不动的荨麻疹成虫的百分比和中位致死时间 (LT ₅₀ ) 值。此外，一些低分子量化合物通过液相色谱与高分辨率质谱联用进行了提取和检测。蜡螟浓度在 SmF 中产生的 132 倍比从 SSF 中获得的高 132 倍，并且在体外和田间观察到对螨种群的更好控制。这些结果表明，通过 SmF生产蜡蚧可以是在花卉作物中实施综合控制策略的更有效替代方案。