The insecticidal activity of recombinant nemertide toxin α-1 from Lineus longissimus towards pests and beneficial species

The nemertide toxins from the phylum Nemertea are a little researched family of neurotoxins with potential for development as biopesticides. Here we report recombinant production α-1 (α-1), 65-residue inhibitor cystine knot (ICK) peptide Lineus longissimus, known to target insect voltage-gated sodium channels. insecticidal activity was assessed and compared well characterised ICK venom peptide, ω-atracotoxin/hexatoxin-Hv1a (Hv1a). elicited potent spastic paralysis when injected into cabbage moth (Mamestra brassicae) larvae; conferring an ED50 3.90 μg/larva (10.30 nmol/g larva), followed by mortality (60% within 48 h after 10 μg injection). By comparison, injection M. brassicae larvae Hv1a produced short-lived flaccid over 6 times greater than that at 26.20 (64.70 larva). Oral toxicity demonstrated against two aphid species (Myzus persicae Acyrthosiphon pisum), respective LC50 values 0.35 0.14 mg/mL, some 6-fold lower those derived Hv1a. When delivered orally larvae, caused both (ED50 11.93 μg/larva, 31.5 larva) mortality. This contrasts lack oral Hv1a, which fed had no effect on feeding or survival. has previously been shown be non-toxic beneficial honeybee (Apis mellifera). contrast, rapid 100% observed following (31.6 insect). These results demonstrate great naturally occurring non-venomous peptides, such α-1, novel effective biopesticides, but equally highlights importance understanding phyletic specificity given toxin early stage in quest discover develop safe sustainable pesticides.