Abstract

Spodoptera frugiperda is considered the most severe maize pest in the world and Ethiopia as well. A survey was conducted during the 2017 and 2018 cropping seasons to determine the distribution, relative importance, and the association between S. frugiperda intensity and biophysical factors. A total of 375 maize fields were surveyed during the two cropping seasons. The spatiotemporal analysis revealed that there was a 100% prevalence of the S. frugiperda with various degrees in both cropping seasons. However, significant variations were observed in the pest incidence and plant damage severity of S. frugiperda among the surveyed districts in the two seasons. There were higher pest incidence and plant damage severity in 2017 than in the 2018 cropping season. Logistic regression analysis was used to analyze the association of S. frugiperda with biophysical factors. Higher (> 75% for both cropping seasons) S. frugiperda plant damage severity was highly associated with Denba Gofa, Zala, Arba Minch, cropping system, altitude, pest management, insecticide spray frequency, and weeding practice with variable levels of significance. Lower plant damage severity of S. frugiperda was highly associated with Burji, high intercropping, altitude, a cultural plus insecticide used in pest management, more than two times insecticide applications, and high weeding practice. The study suggests proper pest management practices should be carried out to reduce S. frugiperda damaged to the maize crop.

摘要

草地贪夜蛾被认为是世界上最严重的玉米害虫，埃塞俄比亚也是如此。在 2017 年和 2018 年种植季节进行了一项调查，以确定草地贪夜蛾的分布、相对重要性以及强度与生物物理因素之间的关联。两个种植季节共调查了 375 块玉米田。时空分析显示，两季草地贪夜蛾患病率均为100%，均有不同程度的发生。然而，草地贪夜蛾的害虫发生率和植物损害严重程度存在显着差异两季调查地区中。2017年病虫害发生率和植物受损严重程度均高于2018年种植季节。采用Logistic回归分析分析草地贪夜蛾与生物物理因素的关联。较高（两个种植季节均> 75%）的草地贪夜蛾植物损害严重程度与 Denba Gofa、Zala、Arba Minch、耕作制度、海拔、害虫管理、杀虫剂喷洒频率和除草实践高度相关，具有不同程度的显着性。降低草地贪夜蛾对植物的损害程度与布尔吉、高间作、海拔高度、害虫防治中使用的文化加杀虫剂、两次以上的杀虫剂施用以及高除草实践高度相关。该研究建议采取适当的害虫管理措施，以减少草地贪夜蛾对玉米作物的损害。