Entomopathogenic activity of Purpureocillium takamizusanense against diverse agricultural pests

Sustainable control of agricultural pests requires alternatives to synthetic pesticides and to the Beauveria/Metarhizium products that dominate fungal biocontrol. Purpureocillium takamizusanense, first described from cicadas in Japan and recently from lychee stink bug in Taiwan, is an emerging entomopathogenic fungus. We assessed the virulence of strain TCTeb01, isolated from naturally infected Tessaratoma papillosa, against three pests from three insect orders. Inoculation significantly reduced cumulative survival in all three hosts (Kaplan-Meier with log-rank, all P < 10^⁻3): Hypothenemus hampei reached 100% mortality by day 6, Thrips palmi 77.5% by day 7, and T. papillosa nymphs 67.5% by day 42. For adult T. papillosa, virulence was concentration-dependent, with 1 × 10⁷ conidia/mL producing 94% cumulative mortality by day 42, significantly higher than at 1 × 105 and 1 × 10⁶. Median lethal times were 3.7 days for H. hampei and T. palmi at 1 × 10⁸ conidia/mL, 19.7 days for T. papillosa nymphs at 1 × 10⁷, and 14.5 days for T. papillosa adults at 1 × 10⁷. Morphological characterization of seven Taiwanese strains extended conidiophore length (up to 169 μm) and documented an Acremonium-like synanamorph; a four-locus phylogeny confirmed species identity. Purpureocillium takamizusanense shows broad-spectrum virulence across Coleoptera, Thysanoptera, and Hemiptera, supporting its potential as a locally adapted biocontrol agent for IPM.