Acroneuria kosztarabi Kondratieff & Kirchner, 1993

Verdone, Chris J., South, Eric J. & Kondratieff, Boris C., 2022, Acroneuria kirchneri Stark & Kondratieff, 2004 is a synonym of Acroneuria kosztarabi Kondratieff & Kirchner, 1993 (Plecoptera: Perlidae), Zootaxa 5094 (1), pp. 177-195 : 182-193

Acroneuria kosztarabi Kondratieff & Kirchner, 1993

( Figs. 2–30 )

Acroneuria kosztarabi Kondratieff & Kirchner, 1993: 550 . Holotype M: Virginia, Tazewell County, Burkes Garden (NMNH) Acroneuria kosztarabi: Stark 2004: 70

Acroneuria kirchneri Stark & Kondratieff, 2004: 393 . Holotype M: Kentucky, Lawrence County, Hood Creek (NMNH) Syn. n. Acroneuria kirchneri: Stark 2004: 70

Material examined. U.S. A –– Kentucky: Breathitt Co., Clemons Fork, Robinson Forest , [37.45513, -83.16545], 17 June 2010, M. Floyd, 1F ( CSUIC SEM) . Harlan Co., [Isaac Creek], Laurel House parking lot, [36.94842, -83.18258], 12 June 2009, J. Robinson, 1F ( CSUIC SEM) . Lawrence Co., Hood Creek , 1.5 mi. S of Blaine, [38.01405, -82.83694], 18 May 1994, B.C. Kondratieff, R.F. Kirchner, 2M, 2F ( CSUIC paratypes SEM) ; same data, 2F ( CSUIC: paratypes) ; Hood Creek, Ross Branch Rd. E of Hwy 201, 37.97299, -82.82796, 30 May 2017, C. Verdone, 10F ( CSUIC DNA) . McCreary Co., Eagle Creek , KY 896, [36.86834, -84.36732], 9 June 2007, M. Floyd, 1F ( CSUIC SEM) . North Carolina, Durham Co., South Fork Little River , SR 1461, 36.149722, -78.94638, 27 May 2021, C. Verdone, 5L ( NCDWR DNA) . Ohio: Adams Co., Upper Churn Creek, [Shawnee] State Forest , [38.77761, -83.33452], 15 June 1995, no collector information, 1F ( INHS OBS-INHS 6435 ) . Hocking Co., Queer Creek, NE South Bloomingville along Hwy 664, [39.42360, -82.59084], 19 June 1996, H. Sharb, 1F ( INHS OBS-INHS 7343 ) . Scioto Co., Mackeltree Run, 8 km NW Friendship at confluence with Lake Roosevelt , [38.72390, -83.18150], 20 June 1999, E. Chapman, 3F ( INHS OBS-INHS 3142 ) . Trumbull Co., Mill Creek, 10 km NE Middlefield at Sweet West Rd. bridge, [41.48940, -80.95670], 4 July 1994, V. Fazion, 1F ( INHS OBS-INHS 3170 ) . Washington Co., Little West Branch, CR3 bridge, E. Decaturville , [39.33224, -81.72322], 18 June 1996, T. Troutner, 1F ( INHS OBS-INHS 6869 ) . Virginia: Bedford Co., Rye Cove Creek, Rte 815, 4 mi. NW of Stuart, [36.65750, -80.32664], 5 July 2008, R.L. Hoffman, 2F ( CSUIC SEM) . Bland Co., Wolf Creek, Rte 614, Stephen Levitt Property , 37.14702, -81.26314, 4 June 2016, C. Verdone, B.C. Kondratieff, 1F ( CSUIC SEM) ; same location, 5 June 2016, C. Verdone, B.C. Kondratieff, 1M, 2F ( CSUIC) ; same location, 6 June 2016, C. Verdone, B.C. Kondratieff, 1F ( CSUIC) ; same location, 8 June 2016, C. Verdone, B.C. Kondratieff, 2F ( CSUIC) ; same location, 23 May 2017, C. Verdone, 1M, 1F ( CSUIC DNA) ; same location, 25 May 2017, C. Verdone, D. Fuller, 1M 3E ( CSUIC) ; same location 27 May 2017, C. Verdone, D. Fuller, 3M, 16 E ( CSUIC) ; same location, 28 May 2017, C. Verdone, 7M, 3F, 5E ( CSUIC) ; same location, 24 May 2021, C. Verdone, 9L ( NCDWR DNA) ; Wolf Creek, Rte 614, Wolf Creek Picnic Area , 37.18026, -81.19496, 8 June 2016, C. Verdone, B.C. Kondratieff, 2M, 1F ( CSUIC) ; same location, 12 June 2016, C. Verdone, B.C. Kondratieff, 2M, 1F ( CSUIC) ; same location, 20 June 2016, C. Verdone, 2M, 1F ( CSUIC DNA) . Franklin Co., Grassy Fork, Rte 619, [36.81097, -79.74516], 2 June 2000, R.L. Hoffman, 1F ( CSUIC SEM) ; Henry Co., Machine Creek, at Rt. 619 Crossing , [36.801867, -79.741136], 12 July 2009, R.L. Hoffman, 1F ( CSUIC SEM) . Patrick Co., Rye Cove Creek , rt. 815, 4 mi. NW of Stuart, [36.65749, -80.32663], 5 July 2008, R.L. Hoffman, 1F ( CSUIC SEM) . Prince William Co., Catharpin Creek, Jackson Hollow Campground , [38.87930, -77.68958], 30 May–15 June 2015, D.R. Smith 1F ( CSUIC SEM) . Cattlets Branch, Bull Run Mtns , [38.83218, -77.70473], 30 July 1998, C. S. Hobson, 1F ( CSUIC SEM) . Rappahannock Co., Covington River, VA Hwy 614, 3 mi W of Washington, 38.70549, -78.21945, 10 July 1989, R.L. Hoffman, 1F ( CSUIC SEM) ; Russell Co., Clinch River, Rte 798 SE of Rte 645 nr. Nash Ford , 36.96550, -82.07750, 24 May 2017, C. Verdone, 1M ( CSUIC DNA) ; same location, 27 May 2017, C. Verdone, D. Fuller, 1F ( CSUIC DNA) . Tazewell Co., Burkes Garden, Flatwoods , [NO GPS], 5 July 1987, V.M. Dalton, 1F ( CSUIC paratype) ; Station Spring Creek, Burkes Garden , [37.10065, -81.36992], 17 August 1987, UV, V.M. Dalton, 1M ( NMNH Holotype) . same data, 1F ( CSUIC SEM) .

Additional records from BOLD and GenBank. Acroneuria kosztarabi : Ohio: Adams Co ., Ohio Brush Creek, 7 km SW, Peebles at Hull Rd. Public Access, 38.89550, -83.45810, 6 July 2008, R.E DeWalt, 1F ( INHS Insect Collection 300959, HQ568845) . Tennessee: Blount Co., Abrams Creek, Abrams Creek Campground , GRSM, 35.6103, -83.9327, 22 July 2001, B.D. Heinold, A. Zimmerman, 1F ( INHS Insect Collection 3458, HQ568938). Scott Co. , Station Camp Creek , downstream Charit Creek Lodge, Big South Fork National River Recreation Area, 36.53600, -84.72600, 27 July 2007, M. Geraghty, C.R. Parker, 1F (BISO-41837269a, PKSTO078-08 ) . Virginia: Smyth Co., North Fork Holston River, Nebo , Rte 622, [36.94202, -81.43780], 12 July 2006 O.S. Flint, Adult (sex unknown) ( NMNH, JN200432 ) .

Additional material examined. Virginia: Bedford Co., Falling Rock Creek, BLRI, 37.56400, -79.40850, 27 May 2017, C. Verdone, D. Fuller, 1M ( CSUIC DNA). Bland Co. , Wolf Creek , Rte 614, Wolf Creek Picnic Area , 37.18030, -81.19500, 12 June 2016, C. Verdone, B.C, Kondratieff, 1M ( CSUIC DNA) . Virginia: Scott Co., Straight Fork, Rte 619, Devils Fork Loop Trail , 36.81860, -82.62720, 06 May 2017, C. Verdone, B.C. Kondratieff, S. Roble, 1M ( CSUIC DNA). Tazewell Co. , Cove Creek , Rte 622, 37.17900, -81.30070, 07 May 2017, C. Verdone, B.C. Kondratieff, S. Roble, 1M ( CSUIC DNA) . Virginia: Amherst Co., Otter Creek, Otter Creek Overlook, BLRI , 37.58802, -79.32760, 27 May 2017, C. Verdone, D. Fuller, 1M, 3N, 1E ( CSUIC DNA); Otter Creek, MP 56.7, BLRI, [37.62370, -79.33459], 17–18 July 2007, C.R. Parker, 7F, 1E ( CSUIC DNA); Pedlar River, FR 315, above Panther Falls , 37.71912, -79.29043, 18 June 2016, C. Verdone, 1M, 1F ( CSUIC DNA). Prince Williams Co., Catharpin Creek, Jackson Hollow Campground , Bull Run M.C ., 38.87930, -77.68958, 3–20 June 2016, D.R. Smith, 5M ( CSUIC DNA). Virginia: Russell Co., Clinch River, Rte 798 SE of Rte 645 Nr. Nash Ford , 36.96550, -82.07750, 24 May 2017, C. Verdone, 1M, 1F ( CSUIC DNA) .

Distribution. U.S.A. – KY, OH, NC, TN, VA, WV*. ( Fig. 1 ) *Specimens from West Virginia reported by Stark & Kondratieff (2004) were not examined. While it is likely those records are valid, they were not included in the distribution map.

Male. ( Fig. 2 ). Macropterous; forewing length, 21.3–23.2 mm; body length, 18.8–20.0 mm (n = 5). General body color yellow-brown. Dorsum of head yellow-brown ( Fig. 3 ); interocellular area enclosed with dark brown pigment; dark pigment extends anterolaterally and recurves posteriorly to a tapered point; pale sinuous M-line anterior to the median ocellus ( Fig. 3 ); frons medium brown; pale bands extend anteriorly from lateral margins of M-line; lateral margins of frons medium brown; epicranial suture extending well beyond the lateral ocelli; postocular rugose spots present ( Fig. 3 ). Antennal scape medium brown, pedicel yellow-brown, flagellum medium brown. Pronotum medium brown with irregular rugosities; posterolateral margins darkened ( Fig. 3 ). Mesonotum and metanotum light to medium brown ( Fig. 3 ); wings hyaline with medium brown veins ( Fig. 4 ). Femora yellow-brown with darkened proximal and distal margins connected by a darkened dorsal stripe ( Fig. 2 ). Tibia yellow brown with darkened proximal margin. Tarsi medium brown. Abdominal terga pale yellow to yellow, darkening laterally; lateral margins medium brown; abdominal sterna yellow; terga 9–10 with paired submedial patches of sensilla basiconica ( Fig. 5 ). Hammer on tergum 9 rounded and moderately sclerotized ( Fig. 6 ). Paraprocts slender, apices acutely pointed, deflected ventrad at apex ( Fig. 5 ). Aedeagus with an apical lobe, ventral lobe and ventral quadrangular lobe; apical lobe broadly rounded basally, tapering to a narrow medial projection ( Figs. 5–8 ); dorsum of apical lobe with a broad, golden-brown chevron-shaped setal patch basally ( Figs. 5, 7 ); apical patch either entire or narrowly divided; basal setal patch situated posterior to basal lobe ( Figs. 5, 7 ); basal patch narrowly divided dorsomedially ( Figs. 5, 7 ); consisting of golden brown setae that encircle the aedeagus; ventral patch of setae extends ventrad and laterad to base of apical lobe ( Fig. 6 ); setae tends to be darker and thicker in the mesal area appearing as a stalk ( Fig. 6 ); basal lobe with a few fine setae dorsally and prominent quadrangular lobe ventrally ( Fig. 8 ).

Female. Macropterous; forewing length, 26.5–29.5 mm (n = 5). Body length, 21.9–24.1 mm (n = 5). General color and morphology similar to the male. Subgenital plate extending 1/3–1/2 the length of tergum 9 ( Figs. 9–11 ); with or without lateral constrictions; with only minor or without medial emargination; occasionally asymmetrical ( Figs. 9–11 ).

Ovum. ( Figs. 12–23 ). Length 509–564 μm; width 370–393 μm (n = 6). Outline strawberry-shaped. Cross- section circular. Collar covered with a removable membranous cap. Chorion completely pitted with irregularly sized punctations. Micropyles situated near apical 1/4 ( Fig. 13 ).

Larva. ( Fig. 24 ). Mature body length 20.0–27.0 mm, (n = 6). General body color pale yellow with contrasting brown markings. Dorsum of head pale yellow with brown pigment extending from the epicranial suture to frontoclypeus; broad pale-yellow M-line anterior to median ocellus completely enclosed by brown pigment; posterior and distal margins of lateral ocelli open to occipital pale area; frontoclypeus pale yellow; labrum medium brown with a small triangular pale area anteromedially ( Fig. 25 ). Antennal scape pale yellow, with or without brown mottling; flagellum pale yellow. Postocular area with a ridge of 25–35 stout setae. Lateral margins of occiput with a non-linear grouping of 10–15 stout setae. Mandibles with 5 teeth and a dense brush of marginal setae; submarginal setae on both venter and dorsum ( Fig. 26 ). Lacinia bidentate ( Fig. 27 ); subapical tooth 4/5 the length of apical tooth; marginal setae receding evenly towards base from subapical tooth; length of marginal setae decreases evenly towards base; basal marginal setae short and bifurcate ( Fig. 27 inset). Maxillary palp 5-segmented and longer than lacinia; galea slightly shorter than lacinia ( Fig. 27 ). Pronotum with contrasting pigment; irregular network of brown pigment medially; anterior and posterior margins with short stout setae; lateral margins of disc pale and without regularly spaced, short stout setae ( Fig. 25 ). Mesonotum and metanotum with contrasting pigment and irregularly spaced hair-like setae; distal and proximal margins of wing pads with short stout setae. Mesosternum Y-arm with a long stem, arms reaching anterior corners of furcal pits. Femora, tibia and tarsi mostly pale yellow; anterior face of femora with brown markings becoming more prominent distally; femora and tibia with long dorsal fringes of silky setae ( Fig. 28 ). Abdominal terga medium brown anteriorly, pale posteriorly; brown bands wavy, typically narrowed medially and covering 1/2–1/3 of respective terga ( Fig. 29A ), but may extend to posterior margin of tergum ( Fig. 30A ); posterior margins with tergum 10 variable, but typically with brown anterior band and thin brown posterior band. Dorsum of abdomen with scattered stout setae; posterior margins with a single row of stout setae. Abdominal sterna 1–9 mostly pale with darkened anterolateral margins becoming progressively darker on each segment; sternum 10 entirely brown, or with a pale medial area. Anal gills present; number of filaments variable, arising from a single origin ( Fig. 29B ) or up to 10 separate origins ( Fig. 30B ) on the dorsal face of each paraproct; gill origins covered with small spicules and bearing several stout setae. ( Fig. 30b ); cerci encircled with a fringe of silky setae arising from among spine whorls; most prominent on the proximal side; typically reduced or absent ventrally ( Fig. 24 ).

Diagnosis. Adults of A.kosztarabi are conspecific with A.kirchneri and they are morphologically indistinguishable from A. filicis . Presently, ova are necessary to morphologically distinguish A. kosztarabi from A. filicis . The ovum of A. kosztarabi is easily separated from A. filicis by the completely pitted chorionic surface. In contrast, the ovum of A. filicis is typically only pitted apically beyond the micropyles (Stark 2004, fig. 7.78), but may be pitted up to approximately 50% of the ovum length (S. A. Grubbs & R. E. DeWalt unpublished data). Larvae of A. kosztarabi are similar to A. filicis and A. frisoni Stark & Brown, 1991 and cannot be distinguished using available keys ( Stark 2017).

Molecular Analysis. The ML analysis of COI barcode sequences also supported the synonymy of the two species ( Fig. 31 ). All haplotypes from Wolf Creek, Virginia representing A. kosztarabi and Hood Creek, Kentucky ( A. kirchneri ), along with specimens from Clinch River, Virginia and South Fork Little River, North Carolina were recovered collectively as a single clade with 100% bootstrap support (BS) ( Fig. 31 ). The remaining haplotypes were recovered as monophyletic groups according to respective species with high nodal support [(BS = 100% for A. abnormis (Newman, 1838) , A. carolinensis (Banks, 1905) , A. internata (Walker, 1852) ; BS = 99% for A. filicis ( Fig. 31 )]. With the exception of A. kosztarabi and A. kirchneri , all minimum interspecific K2P distances were greater than maximum intraspecific K2P distances ( Table 2 ). The sequence for one A. kosztarabi specimen (PKSTO078, Scott County, Tennessee) was identical to that of an A. kirchneri specimen ( MZ364767 , Lawrence County, Kentucky).

Biological notes. Acroneuria kosztarabi occurs in at least nine EPA level III Ecoregions throughout the eastern Nearctic region (USEPA 2019) ( Fig. 1 ). Within these areas adults have been collected near streams of various sizes from small headwaters such as Cattlets Branch, Prince William County, Virginia (drainage area = 3.3 km 2) to rather large drainages such as the Clinch River, Russell County, Virginia (drainage area = 1251 km 2). Based on the presence of multiple age classes, the population in Wolf Creek, Bland County, Virginia appears to have a semivoltine (two year) life cycle, similar to other Acroneuria species with which A. kosztarabi is sympatric. Schmidt & Tarter (1985) documented a two-year life cycle for A. carolinensis in West Virginia. Populations of A. abnormis (Newman, 1838) in Michigan have also been documented as requiring two years ( Bottorff & Knight 1987). Conversely, A. frisoni , which is sympatric with A. kosztarabi in the western part of its range has been documented as having a univoltine life cycle in second-order stream in northern Oklahoma (Ernst & Stewart 1985).

Preferred larval habitat of A. kosztarabi is apparently areas of lower velocity. Larvae were found among other known run/pool dwellers including Stenacron interpunctatum (Say, 1839) , Leucrocuta spp. , Psilotreta spp. and Neophylax spp. Numerous benthic samples taken from riffles produced many A. abnormis , but failed to produce any individuals of A. kosztarabi . The vast majority of emergent larvae and adults collected from Wolf Creek, Bland County, Virginia, were collected adjacent to pools and runs on either concrete structures or riparian vegetation. Similarly, larvae collected from South Fork Little River, Durham County, North Carolina were collected from depositional areas.

Larvae of A. kosztarabi were observed emerging at Wolf Creek from a bridge pool on the evening of 28 May 2017, where emergence apparently began after dusk. The first emergent larva was seen atop the adjacent concrete bridge at 10:30 pm. Emergence continued until approximately 5:30 am, with peak activity occurring between 10:30 pm and 12:00 am. Larvae typically crawled to the bridge ceiling before beginning ecdysis, which lasted between 5 and 13 minutes. This is perhaps the most vulnerable time for A. kosztarabi as they are fully immobilized. Large Dolomedes tenebrosus Hentz, 1831 (dark fishing spiders) were observed feeding on emergent larvae. Following ecdysis, some individuals remained still until fully sclerotized, while others resumed crawling towards a terrestrial refugia.

Based on the examined material, emergence begins in late May. The exact date likely fluctuates annually based on environmental conditions such as air and water temperature. Adults have been collected as late as 17 August from Station Spring Creek, Tazewell County, Virginia. Late emergence of taxa from this location is thought to be in response to the stenothermic conditions of the spring. Type material of Isoperla major Nelson & Kondratieff, 1983 was collected from near this location as late as 7 September ( Nelson & Kondratieff 1983); notably we collected this species on 7 May 2017 from a spring tributary to Cove Creek, Tazewell County, Virginia.

Discussion. Despite being among the more conspicuous stoneflies in eastern North America, Nearctic Acroneuria remains a taxonomic morass. The genus has bewildered prominent plecopterologists for well over a century resulting in 14 Nearctic synonymies (DeWalt et. al 2021). Of the current 17 Nearctic species, five lack larval descriptions and for those that have been described, larval diagnosis relies primarily on highly variable dorsal maculations. Additionally, subtle variations of the ovum chorion and aedeagal setal patterns currently used to distinguish adults, may not be suitable to separate closely related species. Given the history of synonymy and sometimes difficult specimen preparation, we believe the taxonomy of Nearctic Acroneuria could benefit greatly from a comprehensive molecular review, which could promote and bolster future conservation decisions.

Figures

FIGURE 1. Distribution of Acroneuria kosztarabi based on specimens analyzed genetically or with associated ova.

FIGURE 2. Acroneuria kosztarabi, adult male, habitus, dorsal, Wolf Creek, Bland County, Virginia.

FIGURES 3–4. Acroneuria kosztarabi, adult male, Wolf Creek, Bland County, Virginia. 3. Head and pronotum, dorsal. 4. Forewings and hindwings.

FIGURES 5–8. Acroneuria kosztarabi, male, Wolf Creek, Bland County, Virginia. A. Apical lobe. B. Apical setal patch. C. Basal setal patch. D. Basal lobe. E. Dorsomedial division of basal setal patch. F. Quadrangular ventral lobe. G. Ventral setal patch. 5. Terminalia, dorsal. 6. Terminalia, ventral. 7. Aedeagus, dorsal. 8. Aedeagus, ventral.

FIGURES 9–11. Acroneuria kosztarabi, female abdominal sterna 8–10, ventral. 9. Wolf Creek, Bland County, Virginia. 10–11. Hood Creek, Lawrence County, Kentucky.

FIGURES 12–17. Acroneuria kosztarabi, ovum. 12. Station Spring Creek, Tazewell County, Virginia. 13. Wolf Creek, Bland County, Virginia. 14. Grassy Fork, Franklin County, Virginia. 15. Machine Creek, Henry County, Virginia. 16–17. Hood Creek, Lawrence County, Kentucky.

FIGURES 18–23. Acroneuria kosztarabi, ovum. 18. Wolf Creek, Bland County, Virginia. 19. Eagle Creek, McCreary County, Kentucky. 20. Clemons Fork, Breathitt County, Kentucky. 21. Isaac Creek, Harlan Co., Kentucky. 22. Cattlets Branch, Prince William County, Virginia. 23. Covington River, Rappahannock County, Virginia.

FIGURE 24. Acroneuria kosztarabi, larval habitus, dorsal, Wolf Creek, Bland County, Virginia.

FIGURES 25–28. Acroneuria kosztarabi, larva, Wolf Creek, Bland County, Virginia. 25. Head and pronotum, dorsal. 26. Right mandible. 27. Right lacinia (inset, bifurcate marginal setae) 28. Fore- mid- and hind-legs, anterior face.

FIGURES 29–30. Acroneuria kosztarabi, larva, dorsal, (A) abdomen, (B) anal gills. 29. Wolf Creek, Bland County, Virginia. 30. South Fork Little River, Durham County, North Carolina.

FIGURE 31. Maximum Likelihood phylogenetic analysis of 31 Acroneuria haplotypes using the Tamura 3-parameter +I +G nucleotide substitution model. GenBank accession numbers along with collection county and state are listed with corresponding haplotypes. Outgroup taxa include Perlinella ephyre and Remenus bilobatus. Bootstrap support values (> 70%) from 1,000 replicates are displayed at nodes. Scale bar indicates estimated number of nucleotide substitutions per site.