Laboratory Exploration of Several Potential Biocontrol Methods Against the Ambrosia Beetle, Euwallacea interjectus

The ambrosia beetle <i>Euwallacea interjectus</i> Blandford (Coleoptera: Curculionidae: Scolytinae) has recently emerged as a pest in Chinese poplar plantations, causing significant economic losses through damage to host trees in association with its mutualistic fungus <i>Fusarium populicola</i>. This study evaluated the biocontrol potential of <i>Beauveria bassiana</i> strain B-BB-1, <i>Serratia marcescens</i> strain B-SM-1, its metabolite prodigiosin, and two ectoparasitic mites, <i>Pyemotes moseri</i> and <i>Pyemotes zhonghuajia</i>. <i>B. bassiana</i> exhibited significant lethality toward adult female <i>E. interjectus</i>, reduced offspring production, and inhibited <i>F. populicola</i> growth. <i>S. marcescens</i> and prodigiosin had certain lethal effects on larvae and inhibited the growth of <i>F. populicola</i>. Both mites effectively parasitized beetle pupae and larvae, with no significant differences in efficacy between the two species. These agents demonstrate promise for the biological control of <i>E. interjectus</i>, offering insights for managing ambrosia beetle infestations.