Revision of the fern-feeding Chytonidia Schaus, 1914 (=Leucosigma Druce, 1908 NEW SYNONYMY) with a key to adults and a description of 5 new species (Lepidoptera, Noctuidae)

Authors: Goldstein, Paul; JANZEN, D. - University Of Pennsylvania; HALLWACHS, W. - University Of Pennsylvania; Proshek, Benjamin; DAPKEY, TANYA - University Of Pennsylvania

Submitted to: ZooKeys
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/5/2018
Publication Date: 10/18/2018
Citation: Goldstein, P.Z., Janzen, D.H., Hallwachs, W., Proshek, B.T., Dapkey, T. 2018. Revision of the fern-feeding Chytonidia Schaus, 1914 (Leucosigma Druce, 1908 new synonymy) with a key to adults and a description of 5 new species (Lepidoptera, Noctuidae). ZooKeys. 788:87-133.

Interpretive Summary: Ferns occupy a uniquely important role in understanding how insect diets evolve. Fern-feeding insects are sometimes thought to be rare in nature or at least occur in low numbers because ferns possess a unique combination of toxic chemical defenses. This presents Ferns occupy a uniquely important role in understanding how insect diets evolve. Fern-feeding insects are sometimes thought to be rare in nature or at least occur in low numbers because ferns possess a unique combination of toxic chemical defenses. This presents a challenge not only for understanding how herbivores overcome plant chemistry but also for discovering biocontrol solutions to problems with invasive fern species, such as the highly destructive Old World Climbing Fern. For these reasons, the discovery and documentation of fern-feeding species among multiple groups of moths is an important consequence of ongoing caterpillar surveys in the tropics. Here we revise the taxonomy of one of two related groups of owlet moths whose caterpillars have been discovered to be fern-specialists, describe several new species, provide a taxonomic key, and discuss implications for their classification. This work is of interests to chemical ecologists and biocontrol specialists as well as ecologists and plant-insect scientists.

Technical Abstract: Chytonidia Schaus, is one of two related noctuine genera originally described by Schaus and to include species recently associated with ferns (Pteridophyta), specifically Dryopteridaceae and Polypodiaceae, as larval host plants. By examining museum specimens, including all relevant type material, as well as reared material accompanied by DNA barcode data, we synonymize Chytonidia with Leucosigma Druce, 1908 NEW SYNONYMY; re-describe all valid species, including males which we assign to species known from female holotypes; and describe five new species of Leucosigma: L. poolei Goldstein NEW SPECIES; L. schausi Goldstein NEW SPECIES; L. solisae Goldstein NEW SPECIES; and L. davisorum Goldstein NEW SPECIES. Images of adult and, where available, larval habitus as well as dissected genitalia are presented with a taxonomic key to adults. The complex valvae and variously modified male clasping structures are compared with those of the related fern-feeding genus Lophomyra Schaus, with reference both to slide-mounted and in situ images.