Outsmarting wireworms: combining semiochemicals and entomopathogens for sustainable pest management

Wireworms (Coleoptera: Elateridae) are polyphagous soil-dwelling pests causing significant crop losses worldwide. The recent ban on neonicotinoids in Europe has created an urgent need for sustainable control alternatives. Here, we present an integrated research program addressing wireworm management through chemical ecology and biological control.
Our investigations into wireworm host-finding behaviour revealed that larvae use root-emitted volatile organic compounds (VOCs) to locate host plants. In barley, we identified a blend of aldehydes that attracts Agriotes sordidus. Similarly, maize varieties with contrasted field susceptibility showed differential VOC profiles, with less susceptible varieties releasing more diverse blends. In potato, laboratory bioassays confirmed that wireworm feeding activity correlates with variety susceptibility, affecting both larval development and weight gain.
Building on these findings, we developed an attract-and-kill strategy combining plant semiochemicals with entomopathogenic fungi.
We screened 11 entomopathogenic fungal (EPF) strains and identified two highly virulent candidates that significantly reduced larval survival in contact-based assays.
A biodegradable formulation combining wireworms’ attractants with EPF successfully attracted wireworms and achieved up to 74% mortality under laboratory conditions. Applied in sugar beet fields, the formulation led to increased leaf dry mass.
We also evaluated the efficacy of entomopathogenic nematodes (EPN) to control wireworms, with the aim to include them in the attract-and-kill formulation. A comparative study of 16 EPN populations revealed that nematode morphometry, particularly leaner infective juveniles, influences virulence against wireworms. We also characterized the volatile signatures of EPN-infected insect cadavers, identifying specific VOCs that attracted Agriotes larvae, opening new perspectives for biological control applications.
While individually insufficient, these methods appear complementary and compatible, emphasizing the need for integrated pest management strategies combining multiple approaches to maintain crop yields while preserving biodiversity.