Testing local isolates of entomopathogenic microorganisms against Brown Marmorated Stink Bug Halyomorpha halys in Georgia

Abstract

The brown marmorated stink bug, Halyomorpha halys (Hemiptera: Pentatomidae) (BMSB) is an exotic invasive insect which has spread extensively and established in new area of Black sea regions of Georgia. During 2017-2019, infected adults with fungal disease symptoms were found in population of H. halys from different regions of Western Georgia. Three isolates of entomopathogenic fungus Beauveria bassiana sensu lato and one of Isaria cf fumosorosea were recovered. Mycoinsecticide Bover-Ge, based on a local strain of B. bassiana-024 (isolated from soil high mountain of Caucasus Range, provide molecular identification in CABI-UK, gave a unique cultural number - IMI # 501797 and keep in CABI Genetic Recourse Collection) two concentrations (1×107 and 1×108 conidia/ml) was tested on the adults of H. halys in laboratory and its efficiency reached 72.0-90.5%. Under laboratory conditions, local isolates of nematodes Heterorhabditis bacteriophora and Steinernema borjomiensis were tested on H. halys adults. At three increasing concentrations (200, 500 and 1000 IJs/mL), H. bacteriophora caused bug mortality at the rates of 33-47%. As for Steinernema borjomiensis, the respective values were 13-33%.