Soyedina Ricker 1952
Creators: name: Grubbs, Scott A.
name: Baumann, Richard W.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Plecoptera
Nemouridae
Soyedina

description: VIII. Genus Soyedina Ricker, 1952
http://lsid.speciesfile.org/urn:lsid: Plecoptera.speciesfile.org:TaxonName:6133
Type species. Nemoura vallicularia Wu, 1923
Range. Nearctic (DeWalt et al. 2022).
Diagnosis. See Baumann (1975) for a comprehensive description of the genus. Grubbs & Baumann (2019) and Grubbs et al. (2019) provided a morphological- and SEM-based treatment for all 10 eastern Nearctic species. Females cannot be objectively determined to species without direct association with males.
Two keys are presented below. One, the dichotomous key in Grubbs & Baumann (2019) and the slight amendment with S. parkeri presented below are more effective if adult male terminalia are mounted in dorsal view and examined with compound light microscopy with a 10X objective to best visualize important diagnostic characteristics of the epiproct. A depression slide or a counting chamber provides sufficient depth for examination. The male abdomen may need to be dissected from the adult body and softened in a warm 10% solution of potassium hydroxide to manipulate the position of epiproct from recurved over the abdomen to directly posteriorly.
Two, as an alternative for use with standard dissecting light microscopy, an easy guide is also provided that focuses on a combination of the shape of the outer paraproct lobe, the asymmetry exhibited by the epiproct, and geographic distribution. This guide will enable the user to determine adult male specimens to species with minimal uncertainty.
Species key to eastern Nearctic Soyedina adult males
(modified from Grubbs & Baumann 2019)
1 Epiproct slightly asymmetric, especially the paired dorsal sclerites (Figs. 123, 135)................................. 2
- Epiproct distinctly bilaterally asymmetric, including the paired dorsal and ventral sclerites (Figs. 99, 115)............... 3
2 Outer paraproct lobe with a distinct anteriorly-directed sharp spur (Fig. 127)........................... S. kondratieffi
- Outer paraproct lobe apically rounded and markedly expanded (Fig. 137).................................. S. parkeri
3 Inner epiproct member terminated as a blunt process, triangular in shape apically (Figs. 105–107); currently known only from a small geographic area in northern Georgia ....................................................... S. amicalola
- Inner epiproct member round apically, either straight-sided or slightly tapered (Figs. 140–141) or distinctly flanged apically (Figs. 110, 116)....................................................................................... 4
4 Inner epiproct member straight-sided or slightly tapered apically (Figs. 140–141), ventral sclerites typically rounded apically (Fig. 139), outer paraproct lobe robust, with a distinct anteriorly-directed triangular flap (Fig. 143)............. S. sheldoni
- Inner epiproct member distinctly flanged apically (Figs. 110, 116), outer paraproct lobe not as above.................. 5
5 Inner epiproct member flanged and slightly directed laterally, flange lip approximately same width radially (Figs. 116, 130).. ................................................................................................... 6
- Inner epiproct member flanged and directed laterally, flange lip enlarged apically (Figs. 110, 146)..................... 8
6 Outer paraproct lobe subtriangular in shape, terminating with a anteriorly-directed spur (Fig. 133); currently known only from a small geographic area in southwestern Pennsylvania ................................................. S. merritti
- Outer paraproct lobe variable in shape, with (Figs. 120–121, 155) or without an anteriorly-directed spur (Fig. 119)........ 7
7 Outer paraproct lobe variable in shape but not quadrate, with (Figs. 116–117) or without an anteriorly-directed spur (Fig. 119)........................................................................................ S. carolinensis
- Outer paraproct lobe quadrate, with an anteriorly-directed spur (Fig. 155).............................. S. washingtoni
8 Apical portion of outer paraproct lobe narrowed markedly in distal half (Fig. 149)........................ S. vallicularia
- Apical portion of outer paraproct lobe not narrowed markedly in distal half (Figs. 103, 113).......................... 9
9 Outer paraproct lobe straight or slightly convex along dorsal margin (Fig. 103), currently known from middle Tennessee south to northern Alabama and northern Mississippi ..................................................... S. alexandria
- Outer paraproct lobe concave along dorsal margin (Fig. 113), currently known only from the Mammoth Cave region in central Kentucky .................................................................................... S. calcarea
description: Published as part of Grubbs, Scott A. & Baumann, Richard W., 2023, The Nemourinae (Insecta, Nemouridae) of the eastern Nearctic, pp. 1-53 in Zootaxa 5306 (1) on page 31, DOI: 10.11646/zootaxa.5306.1.1, http://zenodo.org/record/8054287