The invention provides nucleic acids, and variants and fragments thereof, obtained from strains of Bacillus thuringiensis encoding polypeptides having pesticidal activity against insect pests, including Lepidoptera. Particular embodiments of the invention provide isolated nucleic acids encoding pesticidal proteins, pesticidal compositions, DNA constructs, and transformed microorganisms and plants comprising a nucleic acid of the embodiments. These compositions find use in methods for controlling pests, especially plant pests.