Soyedina Ricker, 1952

Grubbs, Scott A. & Baumann, Richard W., 2023, The Nemourinae (Insecta, Nemouridae) of the eastern Nearctic, Zootaxa 5306 (1), pp. 1-53 : 31

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

Figures

FIGURES 123‒128. Soyedina kondratieffi. 123, USA, North Carolina, Ball Creek, epiproct, ventral view; 124, USA, Maryland, Mill Run, epiproct apex, ventral view; 125, USA, North Carolina, Ball Creek; epiproct, lateral view; 126, epiproct, caudal view; 127, USA, North Carolina, Ball Creek, outer paraproct lobe, lateral view. 128, USA, Maryland, spring into Dry Run, female, abdominal terminalia, ventral view. c = cercus, ds = dorsal sclerite, im = inner member, vs = ventral sclerite.

FIGURES 135‒138. Soyedina parkeri.135, USA, North Carolina,ATBI plot, epiproct, ventral view; 136, USA, North Carolina, ATBI plot, epiproct apex, ventral view; 137, USA, North Carolina, Wine Spring Creek, outer paraproct lobe, lateral view; 138, USA, North Carolina, ATBI plot, abdominal terminalia, lateral view. ds = dorsal sclerite, im = inner member, vs = ventral sclerite.

FIGURES 99‒104. Soyedina alexandria. 99, USA, Tennessee, tributary to Harpeth River, epiproct, ventral view; 100, USA, Tennessee, tributary to Harpeth River, epiproct apex, ventral view; 101, USA, Tennessee, tributary to Harpeth River, epiproct, lateral view; 102, USA, Alabama, spring into East Fork Scarce Grease Branch, epiproct, caudal view; 103, USA,Alabama, spring into East Fork Scarce Grease Branch, outer paraproct lobe, lateral view; 104, USA, Alabama, spring into Larkin Fork, female abdominal terminalia, ventral view. ds = dorsal sclerite, im = inner member, opl = outer paraproct lobe, vs = ventral sclerite.

FIGURES 115‒122. Soyedina carolinensis. 115, USA, West Virginia, Marsh Fork of Buckhannon River, epiproct, ventral view; 116, USA, North Carolina, Rattlesnake Springs, epiproct, ventral view; 117, USA, North Carolina, Robin Branch, epiproct, lateral view; 118, USA,North Carolina, Robin Branch, epiproct, caudal view; 119, USA, North Carolina, Rattlesnake Springs, outer paraproct lobe, lateral view; 120, USA, Maryland, Fishing Creek, outer paraproct lobe, lateral view; 121, USA, Virginia, seep into Lewis Fork, outer paraproct lobe, lateral view; 122, USA, North Carolina, tributary Connelly Creek, female, abdominal terminalia, ventral view. c = cercus, ds = dorsal sclerite, im = inner member. vs = ventral sclerite.

FIGURES 105‒108. Soyedina amicalola. 105, USA, Georgia, Frogtown Creek. epiproct, ventral view; 106, USA, Georgia, Frogtown Creek, epiproct, lateral view; 107, USA, Georgia, Frogtown Creek, epiproct, caudal view; 108, USA, Georgia, Frogtown Creek, outer paraproct lobe. ds = dorsal sclerite, vs = ventral sclerite, im = inner member, opl = outer paraproct lobe.

FIGURES 139‒144. Soyedina sheldoni. 139, USA, North Carolina, tributary to Holder Creek, epiproct, ventral view; 140, USA, North Carolina, Holder Creek, epiproct apex, ventral view; 141, USA, North Carolina, Holder Creek, epiproct apex, lateral view; 142, USA, North Carolina, Holder Creek, epiproct, caudal view; 143, USA, North Carolina, tributary to Holder Creek outer paraproct lobe, lateral view; 144, USA, North Carolina, Lower Creek, female, abdominal terminalia, ventral view. ds = dorsal sclerite, im = inner member, opl = outer paraproct lobe, vs = ventral sclerite.

FIGURES 109‒114. Soyedina calcarea. 109, USA, Kentucky, springhead to Wet Prong, epiproct, ventral view; 110, USA, Kentucky, springhead to Wet Prong, epiproct, ventral view; 111, USA, Kentucky, springhead to Wet Prong, epiproct, lateral view; 112, USA, Kentucky, springhead to Wet Prong, epiproct, caudal view; 113, USA, Kentucky, tributary to Green River, outer paraproct lobe, lateral view; 114, USA, Kentucky, tributary to Green River, female abdominal terminalia, ventral view. ds = dorsal sclerite, im = inner member, vs = ventral sclerite.

FIGURES 129‒134. Soyedina merritti. 129, USA, Pennsylvania, seep into Powdermill Run, epiproct, ventral view; 130, USA, Pennsylvania, seep into Powdermill Run, epiproct apex, ventral view; 131, USA, Pennsylvania, seep into Indian Creek, epiproct, lateral view; 132, USA, Pennsylvania, seep into Powdermill Run epiproct, caudal view; 133, USA, Pennsylvania, seep into Powdermill Run, outer paraproct lobe, lateral view. 134, USA, Pennsylvania, seep into Powdermill Run, female, abdominal terminalia, ventral view. ds = dorsal sclerite, im = inner member, vs = ventral sclerite.

FIGURES 145‒150. Soyedina vallicularia. 145, USA, Pennsylvania, stream into Traverse Creek, epiproct, ventral view; 146, USA, Maryland, tributary to Trading Run, epiproct apex, ventral view; 147, USA, New York, Kenney Brook, epiproct, lateral view; 148, USA, Maryland, tributary to Fifteenmile Creek, epiproct, caudal view; 149, USA, Kentucky, Spout Spring, outer paraproct lobe, lateral view. 150, USA, Pennsylvania, tributary Traverse Creek, female, abdominal terminalia, ventral view. ds = dorsal sclerite, im = inner member, opl = outer paraproct lobe, vs = ventral sclerite.

FIGURES 151‒156. Soyedina washingtoni. 151, USA, Maine, Thorndike Brook, epiproct, ventral view; 152, USA, Maine, Thorndike Brook, epiproct apex, ventral view; 153, USA, Maryland, spring into Elk Lick Run, epiproct, lateral view; 154, USA, Pennsylvania, Fourmile Creek, epiproct, caudal view; 155, USA, Maryland, Mill Run, outer paraproct lobe, lateral view; 156, USA, Maryland, spring into Blue Lick Run, female, abdominal terminalia, ventral view. ds = dorsal sclerite, im = inner member, opl = outer paraproct lobe, vs = ventral sclerite.