Bioactivity profiling of linear venom peptides from Italian small wood-scorpion (Euscorpius italicus)

Rising host-expansion and the global spread of pest insects, confront agricultural sectors with substantial concerns. A promising source of potential lead compounds to target these growing challenges are animal venoms which abound with a huge diversity of bioactive peptides suited for both pest control and drug discovery. Arachnids in particular contribute substantially to the extreme diversity of highly adapted venom compounds, and for some of these, translational potential in pest control has already been demonstrated. Members of the Euscorpiidae family of scorpions are among the most successful groups of scorpions in Europe. Although they use their venom for hunting, none of their toxins has thus far been functionally evaluated as their low toxicity to humans has kept them out of the spotlight of venom research. We hypothesize that their venom peptides exert insecticidal activity which might be harnessed for pest control applications.

Based on our hypothesis, we conducted bioactivity profiling of linear venom peptides derived from Euscorpius italicus, one of the most common euscorpiid species. In silico analyses revealed them as neutral to cationaic alpha helical peptides with high hydrophobicity. Functionally, our established profiling pipeline that combines in vivo and in vitro bioassays, reveals that one of the tested linear venom peptides, Ei1, causes mortality in Drosophila suzukii postinjection, as well as signs of neuroparalysis. Furthermore, Ei1 exhibits inhibitory effects on Staphylococcus aureus, while also affecting MDCK II cells and equine erythrocytes, implying functions in host defense.

This study reveals insights on properties of Euscorpiidae venom, their ecological values for predation and defensive function against microbial colonization of the venom glands - revealing further knowledge to the growing biodiscovery of animal venoms and potential agricultural functions as a biological insecticide. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.