Targets selection and field evaluation of an RNA biopesticide to control Phyllotreta striolata

Phyllotreta striolata is a major insect pest that threatens vegetable crops worldwide. Recently, its increasing resistance to chemical pesticides underscores the urgent need for novel control strategies. This study explores the potential of RNA biopesticides for managing P. striolata infestations. Transcriptome sequencing of P. striolata generated 42,779 unigenes, which were subsequently compared with genes known to cause 100 % lethality to Tribolium castaneum in the iBeetle database. Forty-eight candidate RNAi target genes were identified, from which six genes-PsHsc70-3, Psfkh, PsRpn11, PsRpt3, Psncm, and PsCoatβ-were selected for further bioassays. Laboratory results indicated that two of these genes, PsRpt3 and PsCoatβ, achieved a 7-day lethality rate exceeding 60 %. These genes were then combined in equal proportions and incorporated into the dsRNA stabilizer MLG01 to form an RNA biopesticide, Ger@dsRNA, for field trials. The initial field trial, conducted in Zhuanghang, Shanghai, showed a 7-day control efficacy of 82.55 ± 6.80 % and 89.11 ± 7.12 % at dsRNA concentrations of 0.1 g/L and 0.5 g/L, respectively. Subsequent field trials in Guangzhou (2022) and Shanghai (2024) yielded similar control effects. This study provides a comprehensive process for the rapid screening of target genes and the development of RNA biopesticides, demonstrating that Ger@dsRNA offers robust preventive efficacy against P. striolata, representing a promising new approach for pest management.