effect of acrostalagmus luteoalbus acro1 on mortality of the second-stage juveniles of the citrus nematode tylenchulus semipenetrans under laboratory conditions

This study investigates the nematicidal activity of acrostalagmus luteoalbus acro1 as a potential biocontrol agent against the citrus nematode tylenchulus semipenetrans under laboratory conditions. the acro1 isolate was cultured in potato extract-dextrose broth, and its nematicidal metabolites were extracted using ethyl acetate. its effectiveness was assessed in comparison to purpureocillium lilacinum, a known biocontrol agent, and abamectin, a chemical nematicide. acro1 demonstrated remarkable nematicidal efficacy, achieving an average mortality rate of 81.5% within 72 hours, significantly surpassing p. lilacinum (46.3%) and the negative control (6.5%). in a secondary experiment, acro1 induced 58.7% mortality in 72 hours, again outperforming p. lilacinum (26.2%) and the control (6.25%). its cell-free culture extract exhibited rapid activity, reaching 76.0% mortality within 24 hours, while its metabolites achieved complete nematicidal efficacy with 100% mortality. by comparison, abamectin induced mortality rates of 53.2%, 62.2%, and 100% at concentrations of 5 ppm, 10 ppm, and 3%, respectively. these findings underscore acro1’s potential as an effective and environmentally friendly alternative to synthetic nematicides, offering a sustainable solution for managing the citrus nematode, a persistent threat to global citrus production.