Capniidae (Lee & Baumann, 2011)

Murányi, Dávid, Gamboa, Maribet & Orci, Kirill Márk, 2014, Zwicknia gen. n., a new genus for the Capnia bifrons species group, with descriptions of three new species based on morphology, drumming signals and molecular genetics, and a synopsis of the West Palaearctic and Nearctic genera of Capniidae (Plecoptera), Zootaxa 3812 (1), pp. 1-82 : 7-13

Capniidae terminalia

In addition to wing venation and thoracic sclerites ( Figs. 53–57 , Tables 1–2 ), the systematics of adult Capniidae is based mainly on the terminalia ( Figs. 1–48 , Tables 3–5 ). This study discusses the structure of the male epiproct, paraprocts, and the fusion plate. These structures are directly involved in mating. The general form and associated structures are illustrated in Figs. 1–31 . These figures are shown to support new generic diagnoses that are presented. A ventral view of the male terminalia is depicted for all genera examined ( Figs. 32–48 ). Terminology and comments are given below:

Basal sclerite (B-scl): The basal portion of the epiproct that can be divided or fused with the main and the laterobasal sclerites (Ep-scl, Lb-scl). It can be vestigial or lacking; its size is usually typical for the genera ( Figs. 1–2, 5–6 , 11–22 , Table 3 ). In some genera the B-scl is developed into the Lower limb (Ll) of the epiproct, see below.

Laterobasal sclerite (Lb-scl): One of two lateral sclerites of the epiproct that are positioned caudally to the Bscl and laterobasally to the Ep-scl (see below). It can be divided or fused with both of those sclerites. The size is also typical for the genera ( Figs. 1–6 , 17–22 , Table 3 ).

Main epiproct sclerite (Ep-scl): The main sclerite of the epiproct, sometimes called the upper limb of the epiproct ( Nelson & Baumann 1987). It is open apically, usually divided in its dorsal portion, and can be divided or entire in its ventral and lateral portion; its ventral connection and lateral division are typical for the genera, as are the presence or absence of setae on its basocaudal portion ( Figs. 1–22 , Table 3 ).

Lower limb (Ll): An epiproctal sclerite is developed from the B-scl ( Figs. 3–6 , Table 3 ). It is large in Utacapnia Gaufin, 1970 and Capnura Banks, 1900 , where the B-scl is completely formed into the Ll and the original sclerite is vestigial or lacking. In Allocapnia Claassen, 1928 , a small Ll is present on the B-scl but not divided. However, the epiproctal portion previously termed Ll in this genus, is in fact the highly separated lower part of the longitudinally divided Ep-scl. A vestigial Ll also present on the vestigial B-scl fused with the Ep-scl in genus Capnia s.s. and in C. s.l. vidua Klapálek 1904 ( Figs. 3–6 ).

Inner sclerite (I-scl): An epiproctal sclerite that is present in some genera, surrounded by the Ep-scl. It is not connected to the Ep-scl but to the membranes forming the epiproct’s inner funnel that fix the Fp and lead the sperm into the apical opening of the epiproct ( Figs. 1–4 , 11–18 , Table 3 ).

Eversible crest (Ec): An eversible, membranous portion of the epiproct on its dorsoapical part, connected to the Ep-scl. Its absence or presence is typical for the genera, although it is difficult to recognize in its contorted state ( Figs. 1–4 , 8–10 , 17–18 , Table 3 ).

Fusion plate (Fp): As described by Klapálek (1896), this organ leads the sperm into the epiproct, and it is more or less fused with the paraprocts ( Fig. 7, 9 ). In this study we note the relative length and width of the organ, and its division or fusion with a small basal sclerite, called the Retractoral plate (Rp) by Hanson (1946) ( Figs. 23–31 , 81 , Table 4 ).

Paraprocts (Pp): The relative length and width of the apical part are typical for the genera, and it is usually related to the dimensions of the Fp ( Figs. 32–48 , 81 , Table 4 ).

Subgenital plate (Sg): In males, its fusion or division with Sternite 9 (St 9) and through this to Tergite 9 (Tg 9) is typical for the genera. If a ventral vesicle is present, the Sg is always separated from the St 9 that is restricted to a well sclerotized arch connecting ventrobasal corners of Tg 9; the vesicle is located on this arch-like St 9, and not on the Sg ( Figs. 32–48 , Table 4 ).

.

Figures

FIGURES 53–55. Thoracal sclerites of male Zwicknia kovacsi Murányi & Gamboa, sp. n.—53: ventral view; 54: lateral view; 55: dorsal view (P: prothoracic; Me: mesothoracic; M: metathoracic—Ab: anterior basalare; Aes: anepisternum; Al: alifer; Bs: basisternum; Cx: coxa; Epm: epimeron; Eps: episternum; Etn: eutrochantin; Fs: furcasternum; Fsa: furcasternal arm; Fsp: furcasternal pit; Kes: katepisternum; Lcs: lateral cervical sclerite; Pb: posterior basalare; Pfs: postfurcasternum; Pn: pronotum; Po: postcoxal bridge; Pr: precoxal bridge; Pra: prealar bridge; Prs: presternum; Psc: prescutum; Pscl: postscutellum; Sct: scutum; Scl: scutellum; Ss: spinasternum; St1: Sternite 1; Tg1: Tergite 1; Tgl: tegula; Tn: trochantin; Tr: trochanter—wings and subalar sclerites omitted)—not to scale.

FIGURES 56–57. Macropterous wings of Zwicknia Murányi, gen. n.—56: Female Z. bifrons (Newman, 1838); 57: male Z. tuberculata (Zhiltzova, 1964) (A: anal vein; a: anal crossvein; arc: arculus; C: costa; Cu: cubital vein; cu-a: cubitoanal crossvein; h: humeral crossvein; M: medial vein; m-cu: mediocubital crossvein; R: radial vein; r: radial crossvein; r-m: radiomedial crossvein; Sc: subcosta)—scale 1 mm.

FIGURES 1–6. Male terminalia of West Palaearctic Capniidae—1–2: Zwicknia bifrons (Newman); 3–4: Capnia s.s. nigra (Pictet); 5–6: Capnia s.l. vidua Klapálek; 1, 3, 5: dorso-caudal view; 2, 4, 6: ventro-caudal view (B-scl: basal sclerite; Cs: caudal setae; Ec: eversible crest; Ep-scl: main epiproct sclerite (shaded in grey); I-scl: inner sclerite; Lb-scl: laterobasal sclerite; Ll: lower limb; Tg 10: tergite 10)—not to scale.

FIGURES 7–10. Male genitalia of Zwicknia Murányi, gen. n.—7, 10: Z. bifrons (Newman); 8–9: Z. rupprechti Murányi, Orci & Gamboa, sp. n.; 7: Fp disconnected to the epiproct, latero-caudal view; 8: epiproct tip with contorted Ec, dorsal view; 9: epiproct with partly everted Ec and Fp connected to the Ep-scl, dorsal view; 10: epiproct with everted Ec, dorso-lateral view (B-scl: basal sclerite; Ec: eversible crest; Ep-scl: main epiproct sclerite; Fp: fusion plate; Lb-scl: laterobasal sclerite; Pp: paraproct; Sg: subgenital plate; Tg 9 p: process of tergite 9; Tg 10: tergite 10)—scales 0.1 mm.

FIGURES 11–16. Male terminalia of East Palaearctic Capnia s.l.—11–12: C. s.l. prolongata Zhiltzova; 13–14: C. s.l. pedestris Kimmins; 15–16: C. s.l. arensi Zhiltzova; 11, 13, 15: dorso-caudal view; 12, 14, 16: ventro-caudal view (B-scl: basal sclerite; Ep-scl: main epiproct sclerite (shaded in grey); I-scl: inner sclerite; Tg 10: tergite 10)—not to scale.

FIGURES 17–22. Male terminalia of Nearctic Capniidae—17–18: Bolshecapnia gregsoni (Ricker); 19–20: Isocapnia grandis (Banks); 21–22: Eucapnopsis brevicauda (Claassen); 17, 19, 21: dorso-caudal view; 18, 20, 22: ventro-caudal view (B-scl: basal sclerite; Ec: eversible crest; Ep-scl: main epiproct sclerite (shaded in grey); I-scl: inner sclerite; Lb-scl: laterobasal sclerite; Tg 10: tergite 10)—not to scale.

FIGURES 23–31. Male paraprocts and fusion plate of Capniidae, dorso-lateral view—23: Zwicknia bifrons (Newman); 24: Capnia s.s. nigra (Pictet); 25: Capnia s.l. vidua Klapálek; 26: Capnia s.l. prolongata Zhiltzova; 27: Capnia s.l. pedestris Kimmins; 28: Capnia s.l. arensi Zhiltzova; 29: Bolshecapnia gregsoni (Ricker); 30: Isocapnia grandis (Banks); 31: Eucapnopsis brevicauda (Claassen) (Fp: fusion plate; Pp: paraproct; Rp: retractoral plate)—not to scale.

FIGURES 32–48. Male terminalia of Capniidae, ventral view—32: Zwicknia bifrons (Newman); 33: Bolshecapnia gregsoni (Ricker); 34: Eucapnopsis stigmatica transversa Aubert; 35: Isocapnia grandis (Banks); 36: Capnia s.l. arensi Zhiltzova; 37: C. s.l. prolongata; 38: C. s.l. pedestris Kimmins; 39: C. s.s. nigra (Pictet); 40: Arsapnia decepta Banks; 41: Allocapnia granulata (Claassen); 42: Mesocapnia silvatica Raušer; 43: Capnura venosa Banks; 44: Utacapnia lemoniana (Nebeker & Gaufin); 45: Paracapnia opis (Newman); 46: Nemocapnia carolina Banks; 47: Capnopsis schilleri schilleri (Rostock); 48: Capnioneura nemuroides Ris (C: cercus; Ep-scl: main epiproct sclerite; Fp: fusion plate; Pp: paraproct; Sg: subgenital plate; St 9: sternite 9; Tg 9: tergite 9; Tg 10: tergite 10; Vv: ventral vesicle)—scale 1 mm.

FIGURES 78–81. Male terminalia of Zwicknia acuta Murányi & Orci, sp. n.; paratype, Slovakia, Banskobystrický Region, Krupinská Planina, Pôtor—78: dorsal view; 79: ventral view; 80: lateral view; 81: caudal view (Fp: fusion plate; Pp: paraproct)—scale 1 mm.

Tables

TABLE 3. Male epiproct of valid extant Capniidae genera. — in case of two character states the first one refers to the type species; for abbreviations of parts see Figs. 1-22.

	B-scl size, /Ep-scl	Lb-scl size, /Ep-scl	Ep-scl ventral connection	Ep-scl laterally	Ep-scl caudal setae	I-scl	Ec	Ll
Allocapnia	medium or large, fused	large, divided	entire	longitudinally divided	present	lacking	absent	present
Apteroperla	lacking?	large?, divided?	?	entire	absent?	long, bifid?	present	absent
Arsapnia	lacking or vestigial	large, fused	entire	apically divided	present	lacking	absent	absent
Baikaloperla	lacking?	large, divided?	?	longitudinally divided?	absent?	?	absent?	absent?
Bolschecapnia	large, divided	small, divided	basal & apical or apical	apically or longitudinally divided	absent	long, divided hook or tube	present	absent
Capnia s.s.	vestigial	large, divided	entire	longitudinally divided	present	small, curved stick	present	vestigial
Capniella	lacking?	large, divided?	?	longitudinally divided	present	?	absent?	present?
Capnioneura	lacking	large, divided	entire	entire	absent	lacking	absent	absent
Capnopsis	small, divided	small, fused	apical	entire	present	long, erect stick	absent	absent
Capnura	lacking	large, divided	entire	entire	vestigial or present	lacking	absent	present
Eocapnia	large?, divided?	small?, fused?	?	entire	absent?	?	absent?	absent
Eucapnopsis	small, divided	small, divided	full divided	entire	absent	lacking	absent	absent
Isocapnia	large, divided	small, divided	entire	entire	absent	lacking	absent	absent
Mesocapnia	small, fused or divided	small, fused	entire	entire	present	lacking	absent	absent
Nemocapnia	large, divided	small, divided	entire	entire	absent	lacking	absent	absent
Paracapnia	vestigial or large, divided	large, hardly divided	entire	entire	absent	lacking	present	absent
Takagripopteryx Utacapnia	large, divided? lacking	small, fused? medium, fused	basal & tip? entire	entire? entire	absent? present	lacking? lacking	absent? absent	absent present
Zwicknia	large, divided	small, divided	basal & tip	apically divided	absent	long, open tube	present	absent

TABLE 4. Male terminalia (besides epiproct) of valid extant Capniidae genera. — in case of two character states the first or the non-parenthesised one refers to the type species; for abbreviations of parts see Figs.7-10, 23, 35, 81.

	Sg/Tg 9	Vesicle	Cercal	Pp apical	Fp length &	Fp/Rp	Tg
			segments	part	width		processes
Allocapnia	fused	absent	many	long,	medium, wide	divided	Tg (7-) 8
				tapering
Apteroperla	fused	absent	many	short	short, wide	divided	Tg (6-7-) 8
Arsapnia	fused	absent	many	long, wide	long, narrow	divided	Tg 7
Baikaloperla	divided?	absent	many	long, wide	?	?	Tg 7-8
Bolschecapnia	divided	present	many	long,	long, narrow	divided	absent
				narrow			or T 9
Capnia s.s.	fused	absent	many	long, wide	long, medium	fused	Tg 7
Capniella	hardly	absent	many	long,	?	?	Tg 6-7 (-8)
	separated			wide?
Capnioneura	fused	absent	one	needle-	long, narrow	fused	absent
				like
Capnopsis	fused	absent	few	short,	medium, wide	divided	absent
				wide
Capnura	divided	absent	many	medium,	long, narrow	divided	Tg 7 (6-8)
				tapering
Eocapnia	fused	absent	many	long,	medium, wide	fused	Tg (7) 8
				wide?
Eucapnopsis	divided	present	few	medium,	long, medium	fused	absent
				tapering
Isocapnia	divided	present	many	long, wide	long, very	divided	absent
					narrow		or Tg 9
Mesocapnia	fused	absent	many	long,	long, medium	divided	absent
				narrow
Nemocapnia	hardly	absent	few	short,	medium, wide	fused	Tg 9
	separated			narrow
Paracapnia	fused	absent	many	long,	short or	divided	absent
				narrow	medium, wide
Takagripopteryx	fused	absent	many	medium,	short, wide	fused	Tg 8 (-9)
				tapering?
Utacapnia	fused	absent	many	long, wide	long, wide	divided	absent
Zwicknia	divided	present	many	short,	long, narrow	divided	Tg 9
				wide