Abstract
Little is known regarding the diversity, abundances and ecology of bark and ambrosia beetles in South Africa. This study investigated the drivers of bark and ambrosia beetle communities, particularly concerning the invasive polyphagous shot hole borer ( Euwallacea fornicatus (Eichoff, 1868); PSHB), in native forests in two ecoregions in South Africa. Forty-six species of Scolytinae and Platypodinae were recorded, representing ~ 21% of the 219 known beetle species in the country. This study highlights significant regional and seasonal differences in beetle diversity and abundance. While the Western Cape and KwaZulu-Natal regions exhibited similar overall species richness, KwaZulu-Natal had a higher number of beetle species. Beetle community composition was influenced by differences between forest types, regions, and seasons. Increased presence of PSHB in native forests correlated with an increased richness of other beetle species, but these results should be interpreted with caution. PSHB may therefore create opportunities for other beetle species. However, the effect of PSHB on assemblages of other taxa and the long-term impacts of its interactions with other species is still unclear. Implications for insect conservation Our study provides novel data on scolytine beetle diversity in native South African forests and the potential effects of an invasive beetle on scolytine beetle assemblages, which has important implications for forest health and management.