Plants and Insect Eggs: First Report of a Katydid Using a Fern as Host for Oviposition

Ferns are the second most diverse lineage of vascular plants worldwide and are particularly abundant in tropical forests. However, the ecological significance of such remarkable diversity has been often underestimated. In this article, we report for the first time the observation of ferns, specifically Polytaenium cajenense (Desv.) Benedict (Polypodiopsida, Pteridaceae), serving as oviposition sites for katydids ( Stilpnochlora sp., Orthoptera: Tettigoniidae) in a remnant of humid tropical forest in Brazil. The identification of the katydid was performed by experts based on egg morphology. The eggs were laid along the margin of the laminae, on the abaxial surface. Interestingly, the eggs seemed to be deposited inside the lamina, and after the oviposition, part of the leaf began a senescence process that exposed the eggs. Phaneropterine katydids are typically generalists regarding plant species or family when it comes to oviposition, but they seem to select material with suitable mechanical properties (e.g. high thickness and stability). We suggest that future experimental studies should include ferns in oviposition tests for katydids, examining how foliar traits such as leaf thickness, orientation, water content, and leaf size influence substrate selection. Future studies should also explore the bidirectional effects between plants and insect eggs, such as phytochemical changes and the production of ovicidal substances, as well as alterations in photosynthetic activity and secondary metabolism. We propose the hypothesis that ferns, which are plants that predominantly occur in low‐light habitats, may provide benefits for egg development in katydids by preventing overheating and dehydration. Our article highlights the potential ecological role of ferns as oviposition sites for katydids.