Diversity and Molecular Barcoding of Stink Bugs (Hemiptera: Pentatomidae) Associated with Macadamia in South Africa.

Stink bugs are major pests of macadamia in South Africa. Accurate identification and knowledge of species composition are important to inform management practices. The overall aims of this study were to identify stink bug species from macadamia orchards in South Africa using morphology, and to establish a DNA database based on the gene region. A total of 21 stink bug species were found in macadamia orchards in KwaZulu-Natal, Limpopo and Mpumalanga provinces. Distant, 1878, was the dominant species throughout all three growing regions. Two unidentified species of Kirkaldy, 1909, here designated as sp. 1 and sp. 2, were the second and third most abundant species found in KwaZulu-Natal. No species of has previously been reported in association with macadamia. Evidence of a cryptic third species of was also found. Species composition fluctuated over three growing seasons in Limpopo and differed between the three growing regions during the 2019-2020 season, highlighting the need for ongoing monitoring of these important pest species. The DNA barcode database developed in this study will be valuable for future monitoring and identifications, including cryptic or polymorphic stink bug species and different life stages.