Life-Stage-Specific Survivorship and Mortality Aetiology of Gonimbrasia belina: The Interplay of Habitat Type, Seasons and Edaphic Factors

Gonimbrasia belina (mopane worms) is a keystone species in the mopane woodland, yet its population dynamics remain unpredictable and poorly understood. This study aims to analyse the survivorship and mortality aetiology of G. belina by evaluating how habitat and seasonal variations interact to influence reproductive fitness, larval and pupal survivorship. The study used multi-factorial experiments and necropsy-based diagnostic frameworks across four sub-sites representing a combination of habitat and season, and the addition of five soil substrates for pupae. The greenhouse increased the overall survivorship (10%) of G. belina compared to natural mopane woodlands (1%). The greenhouse mitigated extrinsic mortality pressure from predation and abiotic stress, but it inadvertently created intrinsic pressures, especially disease and parasitoid-related mortality. The larval stage had the highest killing power, especially in the natural woodland, where predation is severe (65.6%). Pupae were influenced by seasons and soil substrate, with organic soils supporting high moth emergence in the wet season but with high mortality during the dry season (70%), while the addition of mulch to the substrate increased diapause rates. The study shows that natural woodlands under wet conditions serve as reproductive reservoirs where G. belina produces the best. Greenhouses protect against predation and weather, but they attract diseases and parasitoids. The conservation and domestication of G. belina require an integrated approach that preserves natural woodland to enhance productivity. Semi-domestication systems can be utilised as protective nurseries to mitigate predation and abiotic bottlenecks, but there is a need to develop bio-sanitation protocols to protect against pathogens and parasitoids. Clinical trial number: not applicable.