Impact of metal salts on the survival, development, and oviposition behavior of coconut rhinoceros beetle (Coleoptera: Scarabaeidae)

Oryctes rhinoceros (Coleoptera: Scarabaeidae) is an invasive pest of palms in the Pacific Region, including Hawaii, for which limited management options are available. O. larvae develop materials rich organic such as green waste and animal manure. Biosolid within Hawaii’s infestation zone, however, was determined to inhospitable . To determine if elevated metal salts present biosolid responsible this observation, life stages were acutely chronically exposed several at increasing concentrations impact these on survival, development, oviposition behavior. Acute (7 days) exposure mulch rehydrated solutions CaCl 2 , KCl, MgCl or NaCl concentration from 0 0.7 M resulted increased mortality, with > 0.5 generally being 100% lethal both first second-instar larvae. A similar trend survival observed subsequent experiments using a horticultural grade Epsom salt (MgSO 4 ) 1×, 2×, 5× recommended application rate. Chronic (eggs reared through pupation) same rates significantly delayed instar development reduced adult biometrics 1× 2× levels. Similar acute exposure, eggs levels did not hatch, died soon after emergence. In choice experiments, gravid females showed no preference media hydrated water but avoid ovipositing salt. These trials demonstrate potentially novel approach managing populations