Red Listing African Goliath Beetles: Assessing Threats and Conservation Needs

Abstract

The loss of biodiversity is one of the most critical global environmental challenges, driven by deforestation, habitat fragmentation and overexploitation. This study focuses on the biodiversity crisis in Africa, with particular emphasis on the conservation status of the giant Goliath beetles (genus Goliathus Lamarck, Scarabaeidae: Cetoniinae). These beetles, renowned for their large size and striking colouration, are endemic to sub-Saharan Africa. They face significant threats from habitat loss and, potentially, from intensive harvesting for the entomological trade. The conservation status of Goliath beetles needs to be better understood. In this paper, we perform a Red List assessment based on our research carried out opportunistically for 30 years (1994–2024). We present critical data on four taxa of the genus Goliathus: Goliathus goliatus (Linnaeus), Goliathus meleagris Sjöstedt (currently classified as a well-differentiated subspecies of G. goliatus), Goliathus regius Klug and Goliathus cacicus Olivier. Two additional species, Goliathus orientalis Moser (endemic of Tanzania and Northern Mozambique) and Goliathus albosignatus Boheman (broadly distributed in Southern and Eastern Africa), were not assessed due to a lack of original field data. From data gathered opportunistically through incidental observations and field encounters, we analyse habitat preferences, the impact of deforestation and seasonal activity patterns. Our findings highlight the vulnerability of Goliath beetles to ongoing human-induced threats and underline the need for more targeted conservation efforts. However, using Salafsky's standard classification, there were different threats affecting the various species, and the needed conservation actions should, therefore, be species-specific. We applied the 2024 International Union for Conservation of Nature (IUCN) criteria to each species to inform future conservation strategies and support the survival of these remarkable beetles in the wild. Our assessment indicates that G. cacicus should be listed as Critically Endangered due to its catastrophic decline over recent decades, whilst G. regius qualifies as Endangered. Both species inhabit forest habitats in Western Africa. The other taxa assessed were found to be of lesser concern and evaluated as Near Threatened. This study contributes to our broader understanding of biodiversity loss in Africa, stressing the urgency of protecting critical insect populations. In particular, we present a salient example of how multiple overlapping threats endanger biodiversity across large parts of Africa, and in particular forest species in West Africa.