Department of Physics, Faculty of Science, University of Yaoundé 1, P.O. Box 812, Ngoa Ekelle, Yaoundé, Cameroon.
Department of Physics, Faculty of Science, University of Buea, P. O. Box 63, Buea, Cameroon.
Sci Rep. 2022 May 9;12(1):7535. doi: 10.1038/s41598-022-11424-0.
Despite substantial efforts to control locusts they remain periodically a major burden in Africa, causing severe yield loss and hence loss of food and income. Distribution maps indicating the value of the basic reproduction number R was used to identify areas where an insect pest can be controlled by a natural enemy. A dynamic process-based mathematical model integrating essential features of a natural enemy and its interaction with the pest is used to generate R risk maps for insect pest outbreaks, using desert locust and the entomopathogenic fungus Metarhizium acridum (Synn. Metarhizium anisoliae var. acridum) as a case study. This approach provides a tool for evaluating the impact of climatic variables such as temperature and relative humidity and mapping spatial variability on the efficacy of M. acridum as a biocontrol agent against desert locust invasion in Africa. Applications of M. acridum against desert locust in a few selected African countries including Morocco, Kenya, Mali, and Mauritania through monthly spatial projection of R maps for the prevailing climatic condition are illustrated. By combining mathematical modeling with a geographic information system in a spatiotemporal projection as we do in this study, the field implementation of microbial control against locust in an integrated pest management system may be improved. Finally, the practical utility of this model provides insights that may improve the timing of pesticide application in a selected area where efficacy is highly expected.
尽管人们做出了巨大努力来控制蝗虫，但它们仍然周期性地成为非洲的主要负担，导致严重的产量损失，从而导致粮食和收入损失。使用表示基本繁殖数 R 的分布地图来识别可以通过天敌控制害虫的区域。使用沙漠蝗虫和昆虫病原真菌绿僵菌（Synn。Metarhizium anisoliae var。acridum）作为案例研究，使用一种基于动态过程的数学模型，该模型整合了天敌的基本特征及其与害虫的相互作用，生成昆虫病虫害暴发的 R 风险图。这种方法提供了一种工具，用于评估气候变量（如温度和相对湿度）的影响，并绘制空间变异性对绿僵菌作为防治沙漠蝗虫入侵非洲的生物防治剂的功效的影响。通过每月对流行气候条件下的 R 图进行空间投影，展示了在摩洛哥、肯尼亚、马里和毛里塔尼亚等几个选定的非洲国家应用绿僵菌防治沙漠蝗虫的情况。通过将数学建模与地理信息系统相结合进行时空投影，如我们在本研究中所做的那样，可以改进害虫综合管理系统中针对蝗虫的微生物防治的现场实施。最后，该模型的实际应用提供了一些见解，可能会改善在预期效果很高的选定区域中施药的时机。
