Insecticidal toxin (PubMed:8541888, PubMed:8896202). This toxin promotes opening of insect Nav channels. The toxin binds to the S1-S2 and S3-S4 loops in the domain II voltage-sensor of insect Nav channels (i.e., receptor site 4). The American cockroach P.americana is largely resistant to the effects of this toxin due to an unusual sequence within the domain II S1-S2 loop. In vivo, paralyzes lepidopteran and dipteran larvae. Paralyzed insects ultimately die from secondary effects of starvation and dehydration (PubMed:25014760). Expressed by the venom gland. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. PD(50) is 0.38 nmol/g in lepidopteran larvae. LD(50) is 0.231 +- 32 nmol/g in blowfly adult (L.cuprina). LD(50) is 0.493 nmol/g in adult housefly (Musca domestica). This toxin has no effect on the human Nav channel subtypes Nav1.1-Nav1.7, and no effect on hERG (Kv11.1) and Kv2.1. Is non-toxic to mice at 657 pmol/g (4.2 mg/kg) i.p. and 156 pmol/g (1.0 mg/kg) i.c.v. Belongs to the neurotoxin 26 (DTX) family.