The invention provides novel cyclotide polypeptides, and variants and fragments thereof, obtained from Butterfly pea and having pesticidal activity against nematodes. Particular embodiments of the invention provide isolated nucleic acids encoding pesticidal proteins, biopesticide compositions, expression cassettes, and transformed microorganisms and plants comprising a nucleic acid of the invention. These compositions find use in methods for controlling pests, especially plant-parasitic pests such as nematodes and insects.