Causes constriction on isolated rat ileum preparations and relaxation on rat duodenum muscle preparations at amounts higher than bradykinin. Targets bradykinin receptor B2 (BDKRB2). Has insecticidal properties. May be related to the predation of insects by the spider webs. LD(50) is 54 pmoles/mg when injected into honeybees. Dose that causes muscle constriction (ED(50)) is 0.3 uM. Dose that causes muscle relaxation (ED(50)) is 0.2 uM. Has been extracted from the spider web. Belongs to the bradykinin-related peptide family.