The insecticidal Bt proteins (cry proteins) from the gram-positive bacterium Bacillus thuringiensis are used worldwide in transgenic crops for protection against damage by caterpillars and other insect pests. However, concern about potential widespread field-evolved resistance to Bt-toxins has highlighted the urgent need for new, insecticidal proteins with different modes of action. After screening thousands of plant species, we discovered a new family of insecticidal proteins from ferns which has strong activity against the major insect pests of maize and soybean. The crystal structure of one of the variants has been solved and refined to 1.98Å resolution. Remarkably, despite being derived from plants, this protein structurally resembles the Bt bacterial delta endotoxins but only has two domains, lacking the C-terminal domain which is required for the insecticidal activity of the delta endotoxins. This new protein can control insect pests that are resistant to the Bt proteins indicating a different site of action. This presentation will describe our recent characterisation of these fern insecticidal proteins(Fips), their structures and possible modes of action.