Evaluation of fern and moss protein-based defenses against phytophagous insects

Relatively little is known about insect defense mechanisms in the ferns and mosses. The current paradigm is that secondary metabolites and physical barriers are most important in conferring insect resistance in ferns, lycopods, and mosses. We investigated whether protein-based resistance exists in representatives of these taxa. We screened a total of 23 plant species for protein-based insecticidal activity against the two common lepidopteran pests: corn earworm ( Helicoverpa zea) and fall armyworm ( Spodoptera frugiperda). Protein extracts from fern and moss species were compared with those from a lepidopteran-susceptible soybean ( Glycine max) cultivar ( Cobb) in bioassays for insect resistance. The ebony spleenwort ( Asplenium platyneuron), sensitive fern (Onoclea sensibilis), glade fern ( Anthyrium pycnocarpon), and the burned ground moss ( Ceratodon purpureus) protein extracts caused the greatest decrease in damage in leaf-disk assays and insect larval growth. These species are good candidates for follow-up evaluation.