Shuo Feng

BACKGROUND: Aromia bungii (Coleoptera: Cerambycidae) is a major wood‐boring pest of rosaceous fruit trees, whose distribution and impact have expanded considerably in recent years. Conventional chemical control methods often cause environmental pollution, harm natural enemies and compromise fruit safety. RESULTS: In this study, an entomopathogenic fungal strain was isolated and purified from a mummified larva of A. bungii . Based on morphological characteristics and molecular identification, the fungus was identified as Beauveria bassiana and designated as SPT35. The SPT35 strain showed a daily radial growth rate of 3.95 mm/day on SDAY medium at 30 °C. By the tenth day of cultivation, the sporulation yield per unit area and total sporulation yield reached 5.15 × 10 ⁸ spores/cm ² and 6.31 × 10 ⁹ spores/Petri dish respectively. The virulence of SPT35 against both larvae and adults of A. bungii increased with conidia suspension concentration. At 1 × 10 ⁷ spores/mL, the cumulative corrected mortality rates for first‐ to third‐instar larvae after 10 days reached 95.83%, 100% and 95.24%, respectively, with lethal concentration (LC ₅₀ ) values of 7.19 × 10 ² , 1.51 × 10 ⁴ and 1.35 × 10 ⁵ spores/mL. For adults, the cumulative corrected mortality exceeded 50% after 8 days across the tested concentrations, with an LC ₅₀ ranging from 2.45 × 10 ⁷ to 3.84 × 10 ⁷ spores/mL. In field trials, trunk injection treatment with the SPT35 strain at a concentration of 1 × 10 ⁸ spores/mL achieved a control efficacy of 88.93% after 7 days. CONCLUSIONS: The SPT35 strain can serve as an effective microbial agent for controlling A. bungii and holds potential for development into a biocontrol product for practical application. © 2026 Society of Chemical Industry.

Bradysia odoriphaga is a devastating soil pest of Allium tuberosum (Chinese chive), and current control relies heavily on chemical insecticides. Cry39Ab1 toxins from Bacillus thuringiensis (Bt), which are highly toxic to B. odoriphaga, offer an environmentally friendly alternative. However, its mechanism of action remains unclear. In this study, we identified the involvement of vacuolar H⁺-ATPase subunit A (V-ATPase A) in Cry39Ab1 insecticidal activities. The full-length cDNA sequences of BoV-ATPase A was contained 1659 bp open reading frame (ORF), encoding a protein of 552 amino acids with a calculated molecular weight of 59 kDa and an isoelectric point of 9.11. Successful expression and purification of BoV-ATPase A (with GST and His tags) and Cry39Ab1 (with GST and His tags) proteins were achieved. GST pull-down assays demonstrated a direct interaction between recombinant BoV-ATPase A and activated Cry39Ab1 toxin in vitro. Heterologous expression of BoV-ATPase A in Cry-insensitive Sf9 cells conferred susceptibility to Cry39Ab1, resulting in a significant increase in cytolysis compared with control cells. Finally, RNAi-mediated knockdown of BoV-ATPase A in larvae significantly decreased their susceptibility to Cry39Ab1, as evidenced by a marked decrease in mortality. This is the first report that BoV-ATPase A is a key protein required for Cry39Ab1 toxicity, revealing its insecticidal mechanism and establishing BoV-ATPase A as a potential target for pest control.

Bradysia odoriphaga Yang et Zhang damages roots of 30 plant species, resulting in >50% yield loss. Heat stress can not only affect the survival but also affect the expression of heat shock proteins of B. odoriphaga. In this study, two small heat shock protein genes, Hsp21.9 and Hsp22.3, were cloned from B. odoriphaga. The full-length cDNA sequences of BoHsp21.9 and BoHsp22.3 were 749 and 941 bp in length and contained a 588 and 594 bp open reading frame (ORF), encoding a protein of 196 and 198 amino acids with a calculated molecular weight of 21.9 and 22.3 kDa and an isoelectric point of 6.84 and 6.91. Phylogenetic tree analysis showed that BoHsp21.9 and BoHsp22.3 clustered into one branch with flies. qRT-PCR analyses indicated that BoHsp21.9 and BoHsp22.3 were expressed in all tested developmental stages and body segments, especially induced by heat stress. RNAi-mediated silencing of BoHsp21.9 and BoHsp22.3 significantly decreased the survival rate of fourth-instar larvae when exposed to 38 °C. This is the first study on small heat shock proteins in B. odoriphaga, and BoHsp21.9, and BoHsp22.3 play important roles in the molecular mechanism of B. odoriphaga to theromotolerance.