Acts by delaying the inactivation of presynaptic voltage-sensitive sodium channels (Nav). Acts against insects and cause a progressive spastic paralysis. Expressed by the venom gland. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. PD(50) is 0.71 nmol/g in lepidopteran larvae. Belongs to the neurotoxin 26 (DTX) family. The measured molecular weight is 27 daltons higher than the expected one suggesting a sequence error.