Region: Central Africa > Congo Democratic Republic
Categorized: Biology, monitoring, surveillance and scouting
Tagged: agro-ecological zone degree day infestations season Spodoptera frugiperda
Fall Armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae) in South Kivu, DR Congo: Understanding How Season and Environmental Conditions Influence Field Scale Infestations
The fall armyworm (FAW) Spodoptera frugiperda (J. E. Smith) has become a global devastating pest because of its broad dispersal capacity and the high crop damages. At present, research on FAW infestations of crops in the DR Congo remains undocumented. Here, FAW infestations in two agro-ecological zones (Kabare and Ruzizi Plain) were compared in South-Kivu Province. Surveys were carried out during the early 2018 and late 2019 crop seasons to assess the impact of FAW on maize crops. In each agro-ecological zone, 50 fields were selected for investigation. A total of hundred (100) fields were assessed in the 2018 crop season. During the 2019 crop season, the same fields were investigated. The two zones had very different bioclimatic characteristics. FAW attacks were more pronounced under conditions of relatively high temperatures with high evapotranspiration, which occurred in the Ruzizi Plain and late 2019 season. In comparison, Kabare territory and the early 2018 season were characterized by heavy rainfall. The incidence, level of leaf damage, and density of FAW larvae varied significantly with season and agro-ecological zone. The Ruzizi Plain had the highest incidence (60 ± 30%), level of leaf damage and larval density (28.5 ± 19.3). The late 2019 season had the highest incidence (70 ± 20%) as well as the larval density (27.8 ± 19.2). Total annual number of FAW generations was 5.64 and 3.36 in the Ruzizi Plain and Kabare territory, respectively. In conclusion, FAW infestation represents a major problem for agricultural production due to the climatic conditions in the study region.
This is really interesting work Marcellin. It seems similar to what I saw in Kenya – when it is hot and dry, attacks seem to be more prolific than when there is heavy rainfaill. Only an observation, but evidence such as this is very useful. Do you think the insects in the Ruzizi Plain might be a source population for the insects in the Kabare territory, or are they more likely to discrete populations? From what I know, there the altitude winds that are good for insect migration are not common in the DRC because of the rainforest. However, you… Read more »
Thank you for your comment Aislinn and sorry for this late reply. Not all regions of the DR Congo are made up of rainforest climate, the case of the Ruzizi plain and many other corners of the country. In fact, the Ruzizi plain has a rather special climate compared to Kabare which is located next to the Kahuzi Biega National Park. You have just underlined a very important aspect of the research that I had not considered, the action of the wind in the migration of fall armyworm. This would be very important to study.