Floristic characterisation of Lake Chilua and Chiuta plains as outbreak areas of red locust in Mozambique

The red locust (Nomadacris septemfasciata Serville) is one of the most devastating migratory pests of crops in several African countries south of the equator. It originates from small areas characterised by a mosaic of tall and short grasses, known as outbreak areas. The females of this species prefer to lay eggs in clay soils, indicating that the floristic composition and soil characteristics influence the upsurges of red locust. Limited information exists on the abundance and distribution of this important habitat along the country. Therefore, the objective of this study was to characterise the plant community of Lake Chilua and Chiuta plains as outbreak areas of red locust, and to use the obtained data and soil type to identify other potential red locust outbreak areas in Mozambique. A total of 52 plots of 32 m x 32 m and 624 sub-plots of 1 m2 were mapped out and sampled. In the study area, 83 species were found and these taxonomically represented 55 genera and 21 families. The most abundant and frequent species were Cyperus sp. (44.39%), Sesbania sesban (28.21%), Cynodon nlemfuensis (20.81%), Sporobolus sp. (19.71), Ipomoea sp. (19.23%), Hyparrhenia sp. (15.06%), Leersia hexandra (14.58%), Sacciolepis sp. (11.86%), Typha sp. (6.73%) and Panicum dregeanum (6.41%). According to soil type and vegetation (clay and flood plain grassland) observed in the study area, there is likelihood of outbreaks in all provinces of Mozambique. However, Sofala, Zambezia, Niassa and Maputo showed areas with high risk of red locust outbreaks.