Decline of the Commercially Attractive White Morph in Goliath Beetle Polymorphic Populations

Abstract

The Goliath beetle (Goliathus goliatus) is one of the largest and most commercially valuable (for collection exports) beetle species worldwide, and occurs in West and Central Africa, with polymorphic populations being found in Benin, Eastern Nigeria, and Western Cameroun. The white morph is the most commercially valuable, and therefore is actively searched for by hunters and dealers. In a long-term, opportunistically conducted study in south-eastern Nigeria, we documented a substantial decline of the white morph compared to the normally coloured brown morph, although an overall decline in the number of observed beetles was evident for both colour morphs. Although a combination of reasons may have caused the white form decline, it is likely that overcollecting was the primary threat behind the observed pattern. Therefore, we urge the competent authorities to better protect the polymorphic populations of these giant beetles and the International Union for the Conservation of Nature (IUCN) to make a quick assessment for eventual inclusion of the species among the threatened taxa Red List.