D3029: Laboratory efficacy of low-risk insecticides and entomopathogenic fungi on the oriental flower beetle larvae, Protaetia orientalis

The oriental flower beetle (OFB), Protaetia orientalis, is one of the established scarab beetles in Hawaii. It was first discovered on Oahu in 2002, and since then spread to neighbor islands. The adult beetles cause damages to various landscape plants and crops, such as coconut, papaya, mango, corn, etc. This pest has become more of a concern in recent years. In this research, we investigated OFB larval mortality caused by multiple low-risk insecticides on a 7-day time scale: abamectin benzoate, acephate, azadirectin, cyclaniliprole, dinotefuran, emamectin, flypradifurone, imidacloprid, malathion, and Red Palm Weevil Killer. Acephate and cyclaniliprole were found to be statistically significant in causing OFB larvae mortality. Additionally, imidacloprid had an effect on mortality as well. In addition to these chemicals, entomopathogenic fungi were researched. An endemic strain of Metarhizium sp. (2.4 * 10^8 spores/mL and 4.8 * 10^7 spores/mL) and a commercial strain of Beauveria bassiana (2.1 * 10^10 spores/mL and 5.28 * 10^9 spores/mL) were applied in high and low rates over a 14-day time scale to compare efficacy rates on larval mortality. Diapause chamber creation was also noted in this fungal experiment. None of the fungal strains used led to statistically significant results. This research is part of an integrated pest management program to better manage this pest in Hawaii.