Combined Application of Entomopathogenic Fungi and Nematodes Against Larval and Adult Stages of the Agave Weevil, <i>Scyphophorus acupunctatus</i>

ABSTRACT The agave weevil, Scyphophorus acupunctatus , is a key pest of Agave spp. crops, causing severe damage and plant mortality. We evaluated the pathogenicity against adult and larval S. acupunctatus of isolates of the entomopathogenic fungi Beauveria bassiana , B. pseudobassiana , Metarhizium anisopliae and M. pingshaense ; and the entomopathogenic nematodes Steinernema feltiae , S. carpocapsae and Heterorhabditis bacteriophora . While fungal isolates caused low mortality in adults (&lt; 20%), they induced moderate larval mortality (50%–80%) with no significant differences among isolates. Nematode‐induced mortality was also low in adults (&lt; 10%) but significantly higher in larvae, especially with S. carpocapsae (~60%), compared with the other species (&lt; 10%). In dual‐inoculation experiments, using isolates C18/11 ( B. bassiana ) and L21‐1 ( M. anisopliae ) with S. carpocapsae , additive effects were observed in adults, with higher mortality (up to 50%) than in single treatments. Against larvae, S. carpocapsae alone caused high mortality (~98%), which was similar to dual treatments, suggesting limited synergism. Overall, our findings suggest that biological control efforts should focus on the larval stage, where S. carpocapsae shows strong potential as a biological control agent. Future work should evaluate field application strategies to enhance nematode delivery and persistence in agave‐growing environments.