Mutyambai Daniel Munyao, Niassy Saliou, Calatayud Paul-André, Subramanian Sevgan
International Centre of Insect Physiology and Ecology (ICIPE), Nairobi P.O. Box 30772-00100, Kenya.
UMR Évolution, Génomes, Comportement et Écologie, IRD, Université Paris-Saclay, CNRS, 91198 Gif-sur-Yvette, France.
Insects. 2022 Mar 7;13(3):266. doi: 10.3390/insects13030266.
Fall armyworm (FAW), J.E Smith, (Lepidoptera: Noctuidae) is a serious invasive pest of maize that has been established in Kenya since 2016. Little is known about its co-occurrence with resident stemborers, relative infestation and damage and how agronomic factors influence its infestation and damage in maize cropping systems across different agro-ecological zones. This study assessed FAW co-occurrence with resident stemborers, relative infestation and damage across three agro-ecological zones, and the effects of different agronomic practices on its infestation and damage in maize cropping systems in Kenya. A total of 180 maize farms were surveyed across three different agro-ecological zones. FAW infestation and damage was highest in lowlands compared to mid-altitude and high-altitude lands. Its population (eggs and larvae) dominated that of resident stemborers in maize fields. Maize grown under mixed cropping systems, with rainfed production and weeded frequently had low infestation and damage compared to those grown under monoculture, with irrigation and no weeding, respectively. Young vegetative maize plants were more infested and damaged compared to mature plants. Different maize varieties were found to have different infestation and damage levels with Pioneer having the least damage. These results demonstrate that agronomic practices play a role in influencing FAW infestation and damage in maize cropping systems. Further, the population of FAW is dominating that of stemborers in maize cropping systems in Kenya, four years after its invasion. Thus, agronomic practices need to be considered while designing sustainable agro-ecological-based management solutions for resource-constrained smallholder farmers.
草地贪夜蛾（FAW），J.E.史密斯，（鳞翅目：夜蛾科）是玉米的一种严重入侵害虫，自2016年以来已在肯尼亚定殖。关于它与当地蛀茎害虫的共生情况、相对侵染率和危害，以及农艺因素如何影响不同农业生态区玉米种植系统中的侵染和危害，人们了解甚少。本研究评估了草地贪夜蛾与当地蛀茎害虫在三个农业生态区的共生情况、相对侵染率和危害，以及不同农艺措施对肯尼亚玉米种植系统中其侵染和危害的影响。在三个不同的农业生态区共调查了180个玉米农场。与中海拔和高海拔地区相比，低地的草地贪夜蛾侵染和危害最高。其种群（卵和幼虫）在玉米田中占主导地位，超过了当地蛀茎害虫。与分别采用单一栽培、灌溉且不除草的玉米相比，混作系统下种植、雨养生产且经常除草的玉米侵染和危害较低。与成熟植株相比，营养生长阶段的年轻玉米植株受侵染和危害更严重。发现不同玉米品种的侵染和危害水平不同，先锋品种的危害最小。这些结果表明，农艺措施在影响玉米种植系统中草地贪夜蛾的侵染和危害方面发挥着作用。此外，在入侵四年后，肯尼亚玉米种植系统中草地贪夜蛾的种群数量超过了蛀茎害虫。因此，在为资源有限的小农户设计基于可持续农业生态的管理解决方案时，需要考虑农艺措施。
