Efficacy of Beauveria bassiana Ric1 in controlling Zophobas morio larvae: A promising biological approach

The study aimed to evaluate the efficacy of entomopathogenic fungi for the biological control of Zophobas morio (Fabricius, 1776) to prevent economic losses in packaged amylase food products. This study aimed to evaluate the potential of the entomopathogenic fungus Beauveria bassiana Ric1 as a biological control agent against Z. morio. The B. bassiana Ric1 isolate was cultured on Sabouraud Dextrose Agar (SDA), displaying white colonies with irregular edges and producing spherical conidia. Phylogenetic analysis using ITS gene sequences confirmed the isolate's close relation to other B. bassiana strains. Z. morio larvae were exposed to five different conidial concentrations of B. bassiana Ric1 to determine its virulence. The experiments were conducted in triplicate with each group consisting of ten healthy 3rd instar Z. morio larvae. Conidial suspensions at the two highest concentrations (1 × 108 and 1 × 109 conidia/mL−1) resulted in 100% larval mortality within four days. Additionally, 1 × 107 and 1 × 106 conidia/mL−1 concentrations achieved 100% mortality on days six and seven, respectively. The lowest concentration (1 × 105) led to 50% mortality by the end of the bioassay. To confirm that B. bassiana Ric1 caused larval death, the cadavers were incubated on moist paper at room temperature for five days. Mycosis rates of 100% were observed at concentrations of 1 × 108 and 1 × 109, while concentrations of 1 × 107, 1 × 106, and 1 × 105 conidia/mL−1 resulted in mycosis rates of 90%, 80%, and 40%, respectively. The LC50 value of B. bassiana Ric1 was calculated to be 2.06 × 105 conidia/mL−1 for Z. morio larvae. These results indicate that B. bassiana Ric1 is a promising biocontrol agent against Z. morio. •B. bassiana Ric1 caused 100% mortality on 3rd instar larvae of Z. morio at 1 × 108 and 1 × 109 conidia mL−1 concentration within four days.•Mycosis rates of 100% were observed at concentrations of 1 × 108 and 1 × 109 conidia mL−1 concentration.•The LC50 value of B. bassiana Ric1 was calculated to be 2.06 × 105 conidia mL−1.•B. bassiana Ric1 is a promising biocontrol agent against Z. morio.