Attack by Augosoma centaurus (Coleoptera, Scarabaeidae) adults on rattan palm Laccosperma secundiflorum (Arecaceae) in Plateaux Batéké, Gabon

Abstract

An unusual phenomenon consisting of attacks once every two years by adults of a horned beetle on the rattan palm Laccosperma secundiflorum (Arecaceae) (known as ‘French palmier-asperge’) was observed in the Plateaux Batéké (Gabon) over the past decade. Residents reported repeated devastation of rattan palm from May to June, pointing to Pandanus beetle as the pest killing many shoots within populations of this palm species, which is used as a non-timber forest product (NTFP) for alimentary purposes. The ecological area of these attacks includes gallery forests and groves surrounding Ossouele village and neighbouring villages across the border in Congo Brazzaville. The insect fed on and destroyed the rattan heart, starting at its tip, leading to the deterioration and death of L. secundiflorum. Our observations in 2022 allowed us to identify Augosoma centaurus (Coleoptera, Scarabaeidae) as the insect pest devastating this climbing palm, reducing the resource quality and quantity for household consumption and trade. Further studies are needed to increase our understanding of the trophic relationship between the pest and its new adult host/feeding plant.