Sphenoptera sp. (Buprestidae: Coleoptera) threatening wild cancer bush (Sutherlandia frutescens) population

Abstract

Cancer bush (Sutherlandia frutescens) is a medicinal plant indigenous to Southern Africa, important in the treatment of diverse human diseases and ailments. The rampant harvesting in the wild has threatened many indigenous medicinal plants. To safeguard this national treasure, cultivation has been recommended. Recently, substantial insect damage to the wild population of cancer bush in the Limpopo province has been observed. Currently, there are no reports of insect pests associated with cancer bush, hence the objective of this study was to use morphological and molecular tools in the identification of insect pest associated with extensive damage to wild cancer bush populations in Makgophong and Tubatse, Limpopo Province, South Africa from March to June 2023. Plants were cut longitudinally to expose insects inside the stem, and a microscope at 40X magnification, was used to examine the morphological characteristics of insects found. Insect species found were further confirmed using mitochondrial cytochrome c oxidase subunit 1 gene (COI). All life stages of the beetle except the egg stage were observed in the plant, and the morphological and molecular examination of these specimens revealed that the adults and larvae corresponded with the descriptions of Sphenoptera species. This is the first positive confirmation of Sphenoptera species associated with cancer bush and urgent development of management strategies is needed if this plant population (species) is to be conserved.