The sterigma of Fagitana littera Guenée (Lepidoptera: Noctuidae) and its correspondence to structures in the male clasping architecture

Authors: Goldstein, Paul

Submitted to: Proceedings of the Entomological Society of Washington
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/15/2022
Publication Date: 12/1/2022
Citation: Goldstein, P.Z. 2022. The sterigma of Fagitana littera Guenée (Lepidoptera: Noctuidae) and its correspondence to structures in the male clasping architecture. Proceedings of the Entomological Society of Washington. 124(2):251-263. https://doi.org/10.4289/0013-8797.124.2.251.
DOI: https://doi.org/10.4289/0013-8797.124.2.251

Interpretive Summary: This paper describes unique reproductive structures of the Marsh Fern Moth, which is native to the U.S. This moth has no known close relatives but appears related to other fern-feeding species, including candidates for biocontrol agents of the invasive Old World Climbing fern. The newly-described structures are unusual because they represent rare external reproductive locking mechanisms, whereas such mechanisms in Owlet moths are most commonly internal. This work is of interest to entomologists, bio-control specialists, and evolutionary biologists.

Technical Abstract: The genitalia of Fagitana littera Guenée are described with a focus on the complex external copulatory coupling mechanism in the male and female. The female genital plate (sterigma) is robustly developed, with the lamella postvaginalis enclosing a complex of sclerotized, scobinate structures and pockets deriving from the abdominal VIII sternum and tergum, variously fused with elements arising from the sternum and intersegmental membrane of abdominal segments VII and VIII. This scaffold appears to accommodate the robustly developed male clasper, which derives in part from a modification of the valve’s ventro-lateral edge. Such conspicuous and elaborate external coupling mechanisms are rarely reported in Noctuidae.