Prostoia Ricker, 1952

Grubbs, Scott A. & Baumann, Richard W., 2023, The Nemourinae (Insecta, Nemouridae) of the eastern Nearctic, Zootaxa 5306 (1), pp. 1-53 : 22

VI. Genus Prostoia Ricker, 1952

http://lsid.speciesfile.org/urn:lsid: Plecoptera .speciesfile.org:TaxonName:6092

Type species. Nemoura completa Walker, 1852

Range. Nearctic ( DeWalt et al. 2022).

Diagnosis. See Baumann (1975) for a comprehensive description of the genus and Grubbs et al. (2014) for an SEM-based treatment for all five species.

Species key to eastern Nearctic Prostoia adult males and females

(modified from Grubbs et al. 2014)

1 Males .............................................................................................. 2

- Females............................................................................................. 5

2 Dorsal sclerite with secondarily reduced lateral arms ( Fig. 79 ); ventral sclerite bears an ornate, secondarily divided process apically ( Figs. 70, 72‒73 )......................................................................... P. hallasi

- Dorsal sclerite possesses lateral arms ( Figs. 66 , 82 , 88 ); apex of ventral sclerite simple, not divided apically ( Figs. 61 , 77 , 85 ) ................................................................................................... 3

3 Lateral arms longer and sinuous, reaching nearly to ½ the length of the ventral sclerite ( Figs. 85‒87 )............. P. similis

- Lateral arms shorter, extending <¼ the length of the ventral sclerite ( Figs. 66 , 82 ).................................. 4

4 In dorsal view, ventral sclerite parallel-sided in basal ⅓ ( Fig. 61 ); lateral arms sickle-shaped, gradually recurved ( Figs. 66‒67 )........................................................................................... P. completa

- In dorsal view, ventral sclerite gradually widening in basal ⅓ ( Fig. 77 ); lateral arms somewhat triangular in shape, tips flared laterally ( Figs. 74 , 82‒83 ).................................................................... P. ozarkensis

5 7 th and 8 th abdominal sterna not fused medially ( Fig. 75‒76 ), with a well-developed subgenital plate that is convex, extending over the anteromedial margin of the 9 th sternum and slightly notched medially ( Figs. 75‒76 ).................... P. hallasi

- 7 th and 8 th abdominal sterna fused medially, subgenital plate not convex and bearing a distinct medial notch or not ( Figs. 68 , 84 , 93‒94 ).............................................................................................. 6

6 Posterior margin of 8 th sternum with a distinct medial notch, lateral lobes of subgenital plate distinctly angular, projecting ca. 1/4 over anterior margin of 9 th sternum ( Figs. 93‒94 ).................................................. P. similis

- Posterior margin of 8 th sternum with a shallow medial notch, lateral lobes scarcely projecting posteriorly ( Figs. 68 , 84 ).................................................................................. P. completa and P. ozarkensis

Figures

FIGURES 77‒84. Prostoia ozarkensis. 77, USA, Arkansas River, epiproct, dorsal view; 78, USA, Oklahoma, Baron Fork, epiproct, dorsal view; 79, USA, Arkansas River, epiproct, lateral view; 80, USA, Oklahoma, Baron Fork, epiproct apex, lateral view; 81, USA, Oklahoma, Baron Fork, epiproct apex, lateral view; 82, USA, Oklahoma, Baron Fork, epiproct base, caudal view; 83, USA, Illinois, Hutchins Creek, epiproct base, caudal view; 84, USA, Illinois, Hutchins Creek,, female abdominal terminalia, ventral view. c = cercus, la = lateral arm, sgp = subgenital plate, vs = ventral sclerite.

FIGURES 69‒76. Prostoia hallasi. 69, USA, Virginia, Washington Ditch, epiproct, dorsal view; 70, male abdominal terminalia, lateral view; 71, USA, Virginia, Washington Ditch, epiproct, lateral view; 72, USA, Illinois, tributary to Alcorn Creek, epiproct apex, lateral view; 73, USA, Virginia, Washington Ditch, epiproct apex, lateral view; 74, USA, Virginia, Washington Ditch, male abdominal terminalia, caudal view; 75, female abdominal terminalia, ventral view; 76, USA, Virginia, 1 mi SE Dunnsville, female abdominal terminalia, ventral view. c = cercus, la = lateral arm, sgp = subgenital plate, vs = ventral sclerite.

FIGURES 61‒68. Prostoia completa. 61, USA, Wisconsin, Plover River, epiproct, dorsal view; 62, male abdominal terminalia, lateral view; 63, USA, Wisconsin, Plover River, epiproct, lateral view; 64, USA, Wisconsin, Plover River, epiproct apex, dorsolateral view; 65, USA, Wisconsin, Plover River, epiproct apex, dorsal view; 66, epiproct base, dorsal view, USA, Virginia, Roanoke River; 67, Canada, Newfoundland, Walsh River, epiproct base, lateral view; 68, USA, Kentucky, Trammel Fork, female, abdominal terminalia, ventral view. c = cercus, la = lateral arm, sgp = subgenital plate, vs = ventral sclerite.

FIGURES 85‒92. Prostoia similis. 85, USA, Virginia, McClure River, epiproct, dorsal view; 86, male abdominal terminalia, dorsal view; 87, male abdominal terminalia, lateral view; 88, USA, Virginia, McClure River, epiproct, lateral view; 89, USA, Virginia, McClure River, epiproct apex, lateral view; 90, USA, Virginia, McClure River, epiproct apex, dorsal view; 91, USA, Virginia, McClure River, epiproct base, caudal view; 92, USA, Virginia, Big Run, epiproct base, dorsal view. c = cercus, la = lateral arm, vs = ventral sclerite.

FIGURES 93‒94. Prostoia similis. 93, female abdominal terminalia, ventral view; 94, USA, West Virginia, Little Coal River, female abdominal terminalia, ventral view. sgp = subgenital plate.