Cokola Marcellin Cuma, Noël Grégoire, Mugumaarhahama Yannick, Caparros Megido Rudy, Bisimwa Espoir B, Francis Frédéric
Faculty of Agriculture and Environmental Sciences, Department of Crop Sciences, Université Evangélique en Afrique, Bukavu, South Kivu, DR Congo.
Functional and Evolutionary Entomology, Gembloux Agro-Bio Tech, Liege University, Liege, Belgium.
PLoS One. 2024 Dec 2;19(12):e0314615. doi: 10.1371/journal.pone.0314615. eCollection 2024.
There is growing research interest in the fall armyworm (FAW) Spodoptera frugiperda, a polyphagous insect that is a major pest of maize crops worldwide. We investigated the relationship between planting date of maize and FAW infestation in South Kivu, eastern Democratic Republic of Congo, in two sampling seasons (September to October 2020 and February to March 2021). Five planting dates were considered for 45 fields in each season. The incidence, severity of attack and larval density of FAW were assessed at the 8-leaf stage (V8) of maize development in monoculture and intercropping systems. Planting period, classified as late or early, had a strong influence on FAW larval density, incidence and severity. The results showed that the late planting period (mainly on 30 October in season-1 and 30 March in season-2) had the highest larval density, incidence and severity of attack compared to the early planting period (15 September in season-1 and 01 Mars in season-2). During the season-1, five larval stages were found in the same field, whereas all larval stages were present in season-2, regardless of planting period. High densities of L4, L5 and L6 larvae were much more associated with late planting and incidence appeared to be highest when these larvae were present. The presence of L2 and L3 larval stages was observed in maize cropping systems intercropped with soybean and peanuts, while maize in monoculture and intercropped with cassava and beans was colonized by L4, L5 and L6 larvae. This study highlights the existence of different maize planting dates in South Kivu and demonstrates that late plantings have significant FAW infestations compared to early plantings. It provides a basis for developing climate-smart integrated pest management.
对草地贪夜蛾这种多食性昆虫的研究兴趣与日俱增，它是全球玉米作物的主要害虫。我们在刚果民主共和国东部南基伍的两个采样季节（2020年9月至10月和2021年2月至3月）调查了玉米种植日期与草地贪夜蛾侵染之间的关系。每个季节对45块田地考虑了五个种植日期。在单作和间作系统中，于玉米发育的8叶期（V8）评估了草地贪夜蛾的发病率、危害严重程度和幼虫密度。种植期分为晚播或早播，对草地贪夜蛾幼虫密度、发病率和危害严重程度有很大影响。结果表明，与早播期（第一季为9月15日，第二季为3月1日）相比，晚播期（第一季主要为10月30日，第二季为3月30日）的幼虫密度、发病率和危害严重程度最高。在第一季，同一田地发现了五个幼虫阶段，而在第二季，无论种植期如何，所有幼虫阶段都有出现。L4、L5和L6幼虫的高密度与晚播密切相关，当这些幼虫出现时，发病率似乎最高。在与大豆和花生间作的玉米种植系统中观察到了L2和L3幼虫阶段，而单作以及与木薯和豆类间作的玉米则被L4、L5和L6幼虫侵染。本研究突出了南基伍存在不同的玉米种植日期，并表明与早播相比，晚播有显著的草地贪夜蛾侵染情况。它为制定气候智能型综合虫害管理提供了依据。
