Insect and vertebrate active toxin. Binds to site 4 of mammalian voltage-gated sodium channels and shifts the activation voltage of the mammalian Nav1.2a/SCN2A channel to more hyperpolarized voltages, whereas the insect channel, DmNav1 (para), is not affected. Competes for binding at site 3 of the insect sodium channel. Causes temporary paralysis when injected into lepidopteran larvae at 8.6 nmol/g. A low intracranial injection dose into mice causes lacrimation, closure of the eyes and sweating. A high injection dose causes extensive lacrimation and death. Expressed by the venom gland. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. LD(50) is 0.73 pmol/g by intracranial injection into mice. The primary structure of the mature toxin is identical to that of beta-hexatoxin-Mr1a (Raventoxin-III) from Macrothele raveni (AC P61232). Belongs to the neurotoxin 15 family. 01 (magi-5) subfamily.