Dantje Tarore, Vivi Bernadeth Montong, Jusuf Manueke, Yermia Semuel Mokosuli, Lucia Cecilia Mandey
This study investigates the efficacy of the entomopathogenic fungus Beauveria bassiana (Bals.) Vuill. (Ascomycota: Hypocreales) in controlling Necrobia rufipes (De Geer) (Coleoptera: Cleridae), a significant pest responsible for economic losses in copra production, aiming to determine the effective concentration required to achieve substantial mortality and reduce copra damage in storage systems. Employing a completely randomized design with five treatments and three replications, the research assessed B. bassiana concentrations (10%, 15%, 20%, 25%, and 30%) on N. rufipes mortality and copra weight loss across pest population sizes ranging from 8 to 24 adults, with mortality recorded weekly over one month and weight loss measured after one month. Data analysis using analysis of variance, followed by a least significant difference test and probit analysis, revealed mortality rates from 14.67% (±2.31%) at 10% concentration to 69.33% (±3.79%) at 30%, with an LC50 of 23.611% (±1.12%), while copra weight loss increased from 1.33 g (±0.15 g) with 8 adults to 6.87 g (±0.42 g) with 21 adults, strongly correlating with pest density. These findings demonstrate that B. bassiana effectively reduces N. rufipes populations, with higher concentrations enhancing control, and the identified LC50 provides a practical application threshold, underscoring the influence of pest population size on copra weight loss and the need for timely intervention. This approach offers a sustainable, biological strategy to protect copra, potentially minimizing economic losses in tropical storage systems. © Alma Mater Studiorum – Università di Bologna.
Faculty of Agriculture, Sam Ratulangi University, Manado, Indonesia; Postgraduate Program, Sam Ratulangi University, Manado, Indonesia; Faculty of Mathematics and Natural Sciences, Manado State University, Manado, Indonesia