Influence of agro-ecological zone and land management on the occurrence of Gonimbrasia belina in Zimbabwe

Gonimbrasia belina larvae (mopane worms) are a crucial food source and livelihood resource in Zimbabwe, with their spatial distribution closely linked to the conditions of Colophospermum mopane woodlands and prevailing land use management practices. This study aimed to investigate how Agro-Ecological Zones (AEZs IV and V) and land-use types influence the structure of C. mopane woodlands and the occurrence of G. belina larvae in Gwanda District, Zimbabwe. The goal was to determine how C. mopane woodland condition and land management interact to shape G. belina occurrence. Field surveys were conducted from 2019 to 2024 across four sub-sites representing combinations of AEZs and land use. In total, 100 plots (100 × 100 m), with 25 plots per sub site were established to quantify stem density, basal area and leaf area. Gonimbrasia belina occurrence was recorded biannually during harvesting seasons across all plots. Colophospermum mopane stem density and basal area were significantly higher in A2 resettlement areas than in communal lands, within AEZ IV. Gonimbrasia belina occurrence correlated strongly with C. mopane basal area and was approximately 30% higher in resettlement areas. Random Forest modelling identified C. mopane basal area, season and land use as the strongest predictors of G. belina occurrence. Land use management, woodland condition (basal area and stem density) and season are key determinants of G. belina occurrence. Sustainable management requires integrating woodland conservation with community-based governance to ensure both biodiversity and rural food security, while empowering communities to implement and take ownership of the regulatory framework.