Oemopteryx Klapálek, 1902

Verdone, Chris J., Williams, Bronwyn W., Beaty, Steven R., Holland, Victor B., Grubbs, Scott A. & Dewalt, Edward, 2025, The adults, larvae, and systematics of the Nearctic Oemopteryx Klapálek, 1902 (Plecoptera: Taeniopterygidae), Zootaxa 5595 (1), pp. 1-94 : 14-18

publication ID	https://doi.org/10.11646/zootaxa.5595.1.1
publication LSID	lsid:zoobank.org:pub:91BE83A5-8130-4E73-AFDB-6AE50395C8AE
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treatment provided by	Plazi
scientific name	Oemopteryx Klapálek, 1902
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Treatment

Oemopteryx Klapálek, 1902 View in CoL

( Figs 7–12 View FIGURE 7 View FIGURE 8 View FIGURE 9 View FIGURE 10 View FIGURE 11 View FIGURE 12 , 14–25 View FIGURE 14 View FIGURE 15 View FIGURE 16 View FIGURE 17 View FIGURE 18 View FIGURE 19 View FIGURE 20 View FIGURE 21 View FIGURE 22 View FIGURE 23 View FIGURE 24 View FIGURE 25 , 28–32 View FIGURE 28 View FIGURE 29 View FIGURE 30 View FIGURE 31 View FIGURE 32 , 34–38 View FIGURE 34 View FIGURE 35 View FIGURE 36 View FIGURE 37 View FIGURE 38 , 40–49 View FIGURE 40 View FIGURE 41 View FIGURE 42 View FIGURE 43 View FIGURE 44 View FIGURE 45 View FIGURE 46 View FIGURE 47 View FIGURE 48 View FIGURE 49 )

Type species: Taeniopteryx loewii Albarda, 1889 .

Oemopteryx Klapálek, 1902: 179 View in CoL .

Oemopteryx View in CoL : Klapálek 1909: 59.

Taeniopteryx (Oemopteryx) View in CoL : Hanson 1938: 79.

Oemopteryx View in CoL : Illies 1966: 62.

Oemopteryx View in CoL : Zwick 1973: 313.

Oemopteryx View in CoL : Stewart & Stark 2002: 232.

Oemopteryx View in CoL : Zhiltzova 2003: 131.

Oemopteryx View in CoL : Fochetti & Tierno de Figueroa 2006: 2363.

Oemopteryx View in CoL : Baumann & Kondratieff 2009b: 221.

Adult male ( Figs 7A View FIGURE 7 , 8A View FIGURE 8 , 15A View FIGURE 15 , 21A View FIGURE 21 , 28A View FIGURE 28 , 34A View FIGURE 34 , 40A View FIGURE 40 , 45A View FIGURE 45 ). Brachypterous or macropterous. Length of forewings 1.7–8.8 mm (n = 66). Length of body 6.0– 10.4 mm (n = 66). General body color dark-brown.

Head ( Figs 7A View FIGURE 7 , 8A View FIGURE 8 , 15A View FIGURE 15 , 21A View FIGURE 21 , 28A View FIGURE 28 , 34A View FIGURE 34 , 40A View FIGURE 40 , 45A View FIGURE 45 ). Dorsum of head light-brown to dark-brown. Labrum pale anteriorly, brown posteriorly or with brown spots. Anterior frontoclypeus light-brown to brown. Frons with a dark-brown U-shaped marking. Antenna longer than body. Scape, pedicel, and flagella light-brown, yellow-brown to dark-brown. Scape with a distal notch on anterior face. First flagellum subdivided at distal 1/4. Rugosities or pale area anterolateral to lateral ocelli and ecdysial suture. Interocellar area light-brown to dark-brown and slightly depressed. Occasionally with a pale stripe spanning area between eyes across lateral ocelli and interocellar space. Occiput with brown rugosities. Medial areas of the frons, interocellar surface, and occiput covered with fine, pale, clothing hairs.

Thorax ( Figs 7A View FIGURE 7 , 8A View FIGURE 8 , 15A View FIGURE 15 , 21A View FIGURE 21 , 28A View FIGURE 28 , 34A View FIGURE 34 , 40A View FIGURE 40 , 45A View FIGURE 45 ). Pronotum subquadrate, wider than long (length 0.75– 0.85X width) with posterior width slightly wider than anterior width; brown overall with brown rugosities or with a pale medial triangular area that widens posteriorly.Anterior and posterior margins of pronotal flange often pale. Disk with irregular brown rugosities; with or without a transverse sinuous furrow at anterior 1/4. Prosternum moderately sclerotized. Meso- and metathorax dark-brown, lightly to heavily sclerotized dorsally and ventrally. Mesonotum with or without a pale anteromedial spot. Thoracic nota and coxae uniformly covered with sparse, short, fine clothing hairs and with or without longer brown setae. Legs with or without contrasting pigment. Femur pale, distal portion of femur with darker pigment, or with an incomplete mottled brown stripe antero- and posterodorsally. Tibia brown, darker brown on proximal and distal portions, or with proximal callus pale; apex of tibiae with 2-stout apical spines. Tarsus pale to dark-brown. Legs uniformly covered with dark, short stout setae. Forewings brachypterous, extending to posterior margin of tergum-1 with apex acutely pointed, or macropterous; hyaline; venation brown; forewing with or without light mottling; without costal crossveins between humeral crossvein and apex of the subcostal vein which may be forked. Hindwing mottling minimally developed or absent, absent in anal region.

Abdomen. First abdominal tergite either uniformly sclerotized or with a pale stripe ( Fig. 14A View FIGURE 14 ), a U-shaped pale area ( Fig. 20A View FIGURE 20 ), or paired spots ( Fig. 7A View FIGURE 7 ). Abdominal segments 1–9 lightly covered with short, fine clothing hairs. Terga 2–6 uniformly brown; terga 6–9 with or without a well-defined posteromedial membranous cleft. Sterna 1–9 or 2–8 with a pair of anterior sublateral oval brown spots. Sternum-9 with ( Figs 8C View FIGURE 8 , 15C View FIGURE 15 , 21C View FIGURE 21 , 40C View FIGURE 40 , 45C View FIGURE 45 ) or without ( Figs 28C View FIGURE 28 , 34C View FIGURE 34 ) a lightly sclerotized vesicle. Sterna 7–8 lightly sclerotized. Sternum-9 elongated into a scooped plate, lateral margins straight ( Figs 8C View FIGURE 8 , 15C View FIGURE 15 , 21C View FIGURE 21 , 34C View FIGURE 34 , 40C View FIGURE 40 , 45C View FIGURE 45 ) or with rounded lateral margins ( Fig. 28C View FIGURE 28 ); plate with numerous long setae on dorsal and ventral surfaces; plate covering sternum-10 ventrally and extending beyond.

Terminalia ( Figs 9A, 9D View FIGURE 9 , 16A. 16D View FIGURE 16 , 22A, 22D View FIGURE 22 , 29A, 29D View FIGURE 29 , 35A, 35D View FIGURE 35 , 41A, 41D View FIGURE 41 , 46A, 46D View FIGURE 46 ). Abdominal segment-10 nested within segment-9. Anterior margin unsclerotized. Tergal sclerite-10 with a subtle medial cleft and with ( Figs 9A, 9C View FIGURE 9 , 16A, 16C View FIGURE 16 ) or without ( Figs 22A. 22C View FIGURE 22 , 29A, 29C View FIGURE 29 , 35A, 35 C View FIGURE 35 , 41A, 41C View FIGURE 41 , 46A, 46C View FIGURE 46 ,) paired anterior processes with raised scale-like armature. Cercus 3–7 segmented ( Figs 9A, 9D View FIGURE 9 , 16A, 16D View FIGURE 16 , 22A, 22D View FIGURE 22 , 29A, 29D View FIGURE 29 , 35A, 35D View FIGURE 35 , 41A, 41D View FIGURE 41 , 46A, 46D View FIGURE 46 ), excluding vestigial apical segment, and with posteriorly or anteriorly directed basalcercal process covered in socketed setae and sensilla basiconica ( Figs 9A, 9D View FIGURE 9 , 16A, 16a, 16D View FIGURE 16 , 22A, 22D View FIGURE 22 29A, 29D View FIGURE 29 35A, 35D View FIGURE 35 , 41A, 41D View FIGURE 41 , 46A, 46D View FIGURE 46 ). Basal plate of tergum-10 relatively flat ( Figs 9A View FIGURE 9 , 16A View FIGURE 16 , 22A View FIGURE 22 , 29A View FIGURE 29 , 35A View FIGURE 35 ), or produced into paired lobes ( Figs 41A–C View FIGURE 41 , 46A, 46C View FIGURE 46 ). Lateral struts present ( Figs 9A, 9C View FIGURE 9 , 16A, 16C View FIGURE 16 , 22A View FIGURE 22 , 29A View FIGURE 29 , 35A, 35C View FIGURE 35 , 41A View FIGURE 41 , 46A–C View FIGURE 46 ), median strut present ( Figs 29A, 29C View FIGURE 29 , 35A, 35C View FIGURE 35 , 46A–C View FIGURE 46 ), or absent with a small medial point ( Figs 9A, 9C View FIGURE 9 , 16A, 16C View FIGURE 16 , 22A View FIGURE 22 ). Basal bulb, glabrous ( Figs 9A–B, 9E View FIGURE 9 , 16A–B View FIGURE 16 , 22A–B, 22D–E View FIGURE 22 , 41A–B, 41D–E View FIGURE 41 , 46A–C View FIGURE 46 ) or covered in minute raised armature ( Figs 29A–B, 29E View FIGURE 29 , 35A, 35C View FIGURE 35 ), oval, bulbous, moderately sclerotized and with or without an obvious oval inner bulb bearing a small hollow stalk, which terminates at a pore on the anterior face of the anterior epiproct prong. Anterior epiproct prong fused to basal bulb, entire ( Figs 29A–B, 29D–E View FIGURE 29 , 35A–B, 35D–E View FIGURE 35 , 41A–B, 41D–E View FIGURE 41 , 46A–B, 46D–E View FIGURE 46 ) or divided halfway to base ( Figs 9A–B, 9E View FIGURE 9 , 16A–B, 16E View FIGURE 16 , 22A–B, 22E View FIGURE 22 ). Posterior epiproct prong subdivided into 2-processes; ventral process lightly sclerotized, entire ( Figs 29A–B, 29D–E View FIGURE 29 , 35A–B, 35D–E View FIGURE 35 , 41A–B, 41D–E View FIGURE 41 , 46A–B, 46D–E View FIGURE 46 ) or divided near apex into 2-rounded lobes ( Figs 9A–B, 9D–E View FIGURE 9 , 16A, 16D–E View FIGURE 16 , 22A–B, 22D–E View FIGURE 22 ); dorsal process pouch-like, armed with posteriorly directed spine-like setae with an apical sleeve containing 1–3 internal filament(s) ( Figs 35B, 35E View FIGURE 35 , 41B, 41E View FIGURE 41 , 46B, 46E View FIGURE 46 ); filament(s) sometimes visible on left side of basal bulb. Paraprocts subdivided into 2-parts, symmetrical anterior paraprocts and asymmetrical bi-lobed posterior paraprocts. Anterior paraprocts medially directed, minute and lightly sclerotized ( Fig. 46D View FIGURE 46 ) or subrectangular ( Figs 29A View FIGURE 29 , 35A–B View FIGURE 35 ) or conical and well-sclerotized ( Figs 9A–B, 9D–E View FIGURE 9 , 16A–B, 16D View FIGURE 16 , 22A–B View FIGURE 22 ). Posterior paraprocts subdivided, multi-lobed, variable in appearance, fused at base (variously visible in Figs 9A View FIGURE 9 , 16A View FIGURE 16 , 22A View FIGURE 22 , 29A View FIGURE 29 , 41A View FIGURE 41 , 46A View FIGURE 46 ; not visible in Figs 35A–E View FIGURE 35 ).

Adult female ( Figs 8B View FIGURE 8 , 14A View FIGURE 14 , 15B View FIGURE 15 , 20A View FIGURE 20 , 21B View FIGURE 21 , 28B View FIGURE 28 , 34B View FIGURE 34 , 40B View FIGURE 40 , 45B View FIGURE 45 ). Macropterous. Length of forewings 7.6– 14.7 mm (n = 66). Length of body 5.7–13.2 mm (n = 70). General body color brown. Appearance generally similar to male. Forewing without costal crossveins between humeral crossvein and apex of the subcostal vein which may be forked ( Figs 8D View FIGURE 8 , 15D View FIGURE 15 , 21D View FIGURE 21 , 28D View FIGURE 28 , 34D View FIGURE 34 , 40 View FIGURE 40 , 45D View FIGURE 45 ). AA1 vein of forewing with long fine setae ≥1.0 mm ( Fig. 28F View FIGURE 28 ) or short setae ( Figs 8F View FIGURE 8 , 15F View FIGURE 15 , 21F View FIGURE 21 , 34F View FIGURE 34 , 40F View FIGURE 40 , 45F View FIGURE 45 ). Hindwing mottling reduced or absent ( Figs 8D View FIGURE 8 , 15D View FIGURE 15 , 21D View FIGURE 21 , 28D View FIGURE 28 , 34D View FIGURE 34 , 40D View FIGURE 40 , 45D View FIGURE 45 ). Abdominal tergites either unmodified and lightly sclerotized or with contrasting pigment patterns on the first abdominal tergum ( Figs 7 View FIGURE 7 , 14 View FIGURE 14 , 20 C View FIGURE 20 ); lateral margins of abdomen segments 1–8 unsclerotized. Sternum- 8 weakly sclerotized ( Figs 8E View FIGURE 8 , 15E View FIGURE 15 , 21E View FIGURE 21 , 28E View FIGURE 28 , 34E View FIGURE 34 , 40E View FIGURE 40 , 45E View FIGURE 45 ). Terga 9–10 sclerotized dorsally and laterally. Subgenital plate weakly to moderately sclerotized ( Figs 8E View FIGURE 8 , 15E View FIGURE 15 , 21E View FIGURE 21 , 28E View FIGURE 28 , 34E View FIGURE 34 , 40E View FIGURE 40 , 45E View FIGURE 45 ), produced posteriorly with a posterior notch ( Fig. 40E View FIGURE 40 , 42A–B View FIGURE 42 ), without a notch ( Figs 30A–B View FIGURE 30 , 36A–B View FIGURE 36 , 42A–B View FIGURE 42 , 47A–B View FIGURE 47 ) or not produced posteriorly ( Figs 10A–B View FIGURE 10 , 17A–B View FIGURE 17 , 23A–B View FIGURE 23 ). Sternum-9 parabolic ( Figs 8E View FIGURE 8 , 10A–B View FIGURE 10 , 15E View FIGURE 15 , 17A–B View FIGURE 17 , 21E View FIGURE 21 , 23A–B View FIGURE 23 , 28E View FIGURE 28 , 30A–B View FIGURE 30 , 34E View FIGURE 34 , 36A–B View FIGURE 36 , 40E View FIGURE 40 , 42A–B View FIGURE 42 , 45E View FIGURE 45 , 47 A–B View FIGURE 47 ), produced just beyond the apex of abdominal segment-10; length of free portion of sternum-9 0.7–1.0X basal width; uniformly covered with long setae that are longer posteriorly; lateral margins slightly narrowing to a rounded apex. Cercus 4–8 segmented, excluding vestigial apical segment ( Figs 8E View FIGURE 8 , 10A View FIGURE 10 , 17A View FIGURE 17 , 15E View FIGURE 15 , 21E View FIGURE 21 , 23A View FIGURE 23 , 28E View FIGURE 28 , 30A View FIGURE 30 , 34E View FIGURE 34 , 36A View FIGURE 36 , 40E View FIGURE 40 , 42A View FIGURE 42 , 45 E View FIGURE 45 , 47A View FIGURE 47 ).

Ovum. Unknown.

Mature larva ( Figs 11A View FIGURE 11 , 18A View FIGURE 18 , 24A View FIGURE 24 , 31A View FIGURE 31 , 37A View FIGURE 37 , 43A View FIGURE 43 , 48A View FIGURE 48 ). Length of male body 6.4–10.9 mm (n = 40), female body 6.8–13.3 mm (n = 51). General color light-brown to brown. Integument glossy, much of the body with sparse, fine, hair-like sensillae and socketed stout setae, observable at>100X magnification. Specimens generally preserve in a curled posture with the head touching or approaching the abdomen apex, similar to other Taeniopterygidae .

Head ( Figs 11A View FIGURE 11 , 18A View FIGURE 18 , 24A View FIGURE 24 , 31A View FIGURE 31 , 37A View FIGURE 37 , 43A View FIGURE 43 , 48A View FIGURE 48 ). Dorsum of head light-brown to brown with darker brown maculations variously developed. Antelabrum pale to brown; anterior margin with a dense brush of golden setae. Postlabrum pale to brown. Anterior frontoclypeus pale to brown. Frons with or without a brown U-shaped marking with posterolateral extensions; often with light-brown subrectangular markings directly anterior to lateral ocelli. Interocellar area diffusely light-brown to brown. Occipital area light-brown to brown and with irregular brown rugosities. Eyes with pigmented ommatidia sometimes reduced, not reaching eye margins. Antennal scape brown ( Figs 11C View FIGURE 11 , 18C View FIGURE 18 , 24C View FIGURE 24 , 31C View FIGURE 31 , 37C View FIGURE 37 , 43C View FIGURE 43 , 48C View FIGURE 48 ); scape and flagella light-brown to brown; dorsobasal apically inserted setae present ( Figs 31C View FIGURE 31 , 37C View FIGURE 37 , 43C View FIGURE 43 ) or absent ( Figs 11C View FIGURE 11 , 18C View FIGURE 18 , 24C View FIGURE 24 , 48C View FIGURE 48 ); antenna slightly shorter than body ( Figs 11A View FIGURE 11 , 18A View FIGURE 18 , 24A View FIGURE 24 , 31A View FIGURE 31 , 37A View FIGURE 37 , 43A View FIGURE 43 , 48A View FIGURE 48 ).

Maxilla ( Figs 12A–B View FIGURE 12 , 19A–B View FIGURE 19 , 25A–B View FIGURE 25 , 32A–B View FIGURE 32 , 38A–B View FIGURE 38 , 44A–B View FIGURE 44 , 49A–B View FIGURE 49 ). Lacinia triangular with a straight, convex or sinuous inner margin. Lacinia with 2-apical, cupped teeth and 1–7 subapical denticle(s) on ventral face (SD in Fig. 12B View FIGURE 12 square inset). Apical teeth subequal in length; relative length of apical teeth to palm length difficult to discern due to wear. Inner palm margin with 10–19 stout socketed marginal setae below apical teeth; first marginal seta robust. Basal 1/3 of palm with a cluster of 6–10 thin dorsal setae.Acutely pointed sensilla basiconica on various locations on palm surface. Galea with a dense brush of curved setae on the distal apical margin, which transition to sparse peg-like setae at the apical 1/4; a thin patch of setae on inner margin below apical setae, which extends about 1/2–2/3 to base. Length of galea, including apical setae 1.1–1.3X length of lacinia; width of galea 0.8–1.3X the lacinia width. Maxillary palp with 5-segments; 1.7–2.2X length of lacinia; palp with sensilla basiconica variously developed.

Mandible. Right mandible ( Figs 12C View FIGURE 12 , 19C View FIGURE 19 , 25C View FIGURE 25 , 32C View FIGURE 32 , 38C View FIGURE 38 , 44C View FIGURE 44 , 49C View FIGURE 49 ) bicuspid, outer cusp with 2–3 teeth, inner cusp with 1-tooth. Molar pad adorned with marginal rows of pointed acanthae (length 1.0–2.1X width). Palm dorsum with 1–11 dorsal sensillae adjacent to molar pad (requires focusing through the mandible) ( Figs 12C View FIGURE 12 , 19C View FIGURE 19 , 25C View FIGURE 25 , 32C View FIGURE 32 , 38C View FIGURE 38 , 44C View FIGURE 44 , 49C View FIGURE 49 square inset); proximal basal corner with a marginal patch of 3–5 hair-like, branched setae. Ventro-apical setal patch extending from outer cusp to beyond the inner cusp basally (indicated by dotted line in Figs 12C View FIGURE 12 , 19C View FIGURE 19 , 25C View FIGURE 25 , 32C View FIGURE 32 , 38C View FIGURE 38 , 44C View FIGURE 44 , 49C View FIGURE 49 ). Left mandible ( Figs 12D View FIGURE 12 , 19D View FIGURE 19 , 25D View FIGURE 25 , 32D View FIGURE 32 , 38D View FIGURE 38 , 44D View FIGURE 44 , 49D View FIGURE 49 ) bicuspid, outer cusp with 4–5 teeth, inner cusp with 5-tooth. Molar pad with marginal rows of rounded acanthae and long pointed acanthae (length 2.0–4.5X width). Palm dorsum with 1–12 dorsal sensillae adjacent to molar pad ( Figs 12D View FIGURE 12 , 19D View FIGURE 19 , 25D View FIGURE 25 , 32D View FIGURE 32 , 38D View FIGURE 38 , 44D View FIGURE 44 , 49D View FIGURE 49 circle inset); proximal basal corner with a marginal patch of 3–5 hair-like, branched setae. Ventral palm setae extending from outer cusp to beyond the inner cusp basally (indicated by dotted line in Figs 12D View FIGURE 12 , 19D View FIGURE 19 , 25D View FIGURE 25 , 32D View FIGURE 32 , 38D View FIGURE 38 , 44D View FIGURE 44 , 49D View FIGURE 49 )

Thorax ( Figs11A View FIGURE 11 , 18A View FIGURE 18 , 24A View FIGURE 24 , 31A View FIGURE 31 , 37A View FIGURE 37 , 43A View FIGURE 43 , 48A View FIGURE 48 ).Pronotum wider posteriorly; light-brown with faint rugosities and with or without a pale posteromedial spot. Length of forewing pad 1.0–3.9X width. Length of hindwing pad 1.8–2.0X width. Venter of thorax pale. Prothoracic presternum mostly glabrous with light-brown spicules laterally and a pair of elongate lateral cervical sclerites. Prothoracic basisternum and furcasternum light-brown; spicules dense medially and sporadic distally, or absent. Mesothorax with an oval prefurcasternal pit; light-brown spicules present both anterior and posterior to pit; lateral areas glabrous. Mesothoracic basisternum with light-brown spicules mostly concentrated medially. Furcasternal pit present between mesothoracic legs; furcasternum triangular (length 0.5–1.2 width). Metathoracic basisterna with a medial patch of light-brown spicules and a pair of furcasternal pits. Femur and tibia pale to light-brown ( Figs 11D View FIGURE 11 , 18D View FIGURE 18 , 24D View FIGURE 24 , 31D View FIGURE 31 , 37D View FIGURE 37 , 43D View FIGURE 43 , 48D View FIGURE 48 ) and with a fringe of silky setae (not shown); length of femoral setae 0.5–1.5X width of the femur; length of tibial setae about 1.0–1.4X tibial width. Anterior and posterior faces of the femur with scattered short stout setae. Tibial callus, an area of thickened integument on the proximal end of the tibia, pale or darkened ( Figs 11D View FIGURE 11 , 18D View FIGURE 18 , 24D View FIGURE 24 , 31D View FIGURE 31 , 37D View FIGURE 37 , 43D View FIGURE 43 , 48D View FIGURE 48 ). Tarsus with a sparse dorsal fringe of silky setae (not shown); tarsus entirely pale or light-brown and becoming progressively darker distally. Venter of tibia and tarsus with scattered short stout setae.

Abdomen ( Figs 11E View FIGURE 11 , 18E View FIGURE 18 , 24E View FIGURE 24 , 31E View FIGURE 31 , 37E View FIGURE 37 , 43E View FIGURE 43 , 48E View FIGURE 48 ). Dorsum of abdomen uniformly light-brown to brown. Posterior margins of terga with a single row of short, stout sensillae. Posterior margins of tergum-8 and tergum-9 or terga 8–10 with a pair of thin, erect, submedial setae. Venter of abdomen pale; sterna 1–8 with light-brown spicules. Sternum-9 with an elongate plate (male = length 1.4–1.7X width; female = length 1.5–1.9X width); plate width relative to sternal width (male = 0.7–0.9X; female = 0.7–0.8X). Male plate ( Figs 11F View FIGURE 11 , 18F View FIGURE 18 , 24F View FIGURE 24 , 31F View FIGURE 31 , 37F View FIGURE 37 , 43F View FIGURE 43 , 48F View FIGURE 48 ) with sides slightly widening towards posterior margin of sternum-9, posterolateral margins convex, evenly rounded towards apex. Female plate ( Figs 11G View FIGURE 11 , 18G View FIGURE 18 , 24G View FIGURE 24 , 31G View FIGURE 31 , 37G View FIGURE 37 , 43G View FIGURE 43 , 48G View FIGURE 48 ) narrower basally, widest at posterior margin of sternum-9; posterolateral margins linear or convex, evenly narrowing towards apex. Plates of both males and females with stout setae sparse on basal half, becoming denser towards apex. Cercus uniformly light-brown to brown; dorsobasal apically inserted setae absent; cercus about as long as body ( Figs 11A View FIGURE 11 , 18A View FIGURE 18 , 24A View FIGURE 24 , 31A View FIGURE 31 , 37A View FIGURE 37 , 43A View FIGURE 43 , 48A View FIGURE 48 ).

Diagnosis. The genus Oemopteryx is defined in the adult male by the epiproct being composed of two prongs. Females are distinguished by their parabolic 9 th sternum and the forewing lacking costal crossveins between the humeral crossvein and the apical crossvein of the posterior Subcosta. The larvae are differentiated by having both basal cercal and antennal segments with apically inserted setae, or having both absent; the lateral margins of the 9 th sternal plate usually convex at the apical 1/3; the lack of an inner tibial fringe on pro- and meso-thoracic legs and the ventro-apical patch of setae on the left mandible extends proximally to, or past the base of the basal tooth of the outer cusp.

Biological notes. Nearctic Oemopteryx larvae are found in small upland streams in the Appalachians, Sierra Nevada, and Cascades, as well as larger rivers across Canada’s Atlantic, Central, and Prairie provinces, and the U.S. Northeast, Upper Midwest, and Rocky Mountain plateaus. A univoltine life cycle and larval diapause has been hypothesized for four species based on life history studies ( Dosdall & Lehmkuhl 1979, Nelson 1982, Harper et al. 1991). Larvae are usually present from October through April and are most commonly found in gravel riffles. Mouthpart morphology and wear suggests Oemopteryx larvae are scrappers. Adults can be active from mid-January to mid-June depending on elevation and latitude.

Nearctic Oemopteryx morphological species groups

The Oemopteryx contorta Group

The Oemopteryx contorta Group includes O. bimaculata sp. nov., O. contorta , and O. tuscarora sp. nov. Species of this group have larvae without dorsobasal apically inserted setae on the antenna and cercus ( Figs 11B–C View FIGURE 11 , 18B–C View FIGURE 18 , 24B–C View FIGURE 24 ) and lack maxillary palp setae ( Figs 12A–B View FIGURE 12 , 19A–B View FIGURE 19 , 25A–B View FIGURE 25 ). Adult males have a broadly circular vesicle on sternum-9 ( Figs 8C View FIGURE 8 , 15C View FIGURE 15 , 21C View FIGURE 21 ) that is attached to sternum-9 from beneath the vesicle; an anterior epiproct prong that is divided apically ( Figs 9A–B, 9E View FIGURE 9 , 16A–B, 16E View FIGURE 16 , 22A–B, 22E View FIGURE 22 ) and a basal plate of tergum-10 that lacks lobes and a median strut ( Figs 9A, 9C View FIGURE 9 , 16A, 16C View FIGURE 16 , 22A View FIGURE 22 ). Additionally, males have low, rounded, posteriorly directed basal cercal processes ( Figs 9A, 9D View FIGURE 9 , 16A, 16D View FIGURE 16 , 22A, 22D View FIGURE 22 ). The subgenital plate of the females is not produced posteriorly ( Figs 10A–B View FIGURE 10 , 17A–B View FIGURE 17 , 23A–B View FIGURE 23 ).

The Oemopteryx glacialis Group

The Oemopteryx glacialis Group includes O. fosketti and O. glacialis . Species of this group have larvae with dorsobasal apically inserted setae on the cercus and antenna ( Figs 31B–C View FIGURE 31 , 37B–C View FIGURE 37 ), but lack maxillary palp setae ( Figs 32A–B View FIGURE 32 , 38A–B View FIGURE 38 ). Adult males have short, upturned forewings ( Figs 28A View FIGURE 28 , 34A View FIGURE 34 ), an anterior epiproct prong with a trilobed apex ( Figs 29A–B View FIGURE 29 , 35A–B View FIGURE 35 ), a basal plate of tergum-10 with weakly developed lobes and a median strut ( Figs 29A, 29C View FIGURE 29 , 35A, 35C View FIGURE 35 ). Additionally, males have simple, posteriorly directed, finger-like basal cercal processes ( Figs 29A, 29D–E View FIGURE 29 , 35A, 35D–E View FIGURE 35 ) and lack a vesicle on sternum-9 ( Figs 28C View FIGURE 28 , 34C View FIGURE 34 ). The subgenital plate of the females is moderately produced posteriorly ( Figs 28E View FIGURE 28 , 30A–B View FIGURE 30 , 34E View FIGURE 34 , 36A–B View FIGURE 36 ). The description of O. loewii is strikingly similar to the species of the O. glacialis Group suggesting it could be placed in the same species group. However, because O. loewii is presumably extinct, only pinned females are available for study and the scope of the current project is limited to the Nearctic species, no revision to the O. loewii Group is proposed at this time.

The Oemopteryx leei Group

The Oemopteryx leei Group is represented only by O. leei . The larvae of this group have dorsobasal apically inserted setae on the cercus and antenna ( Figs 43B–C View FIGURE 43 ) and hair-like sensillae on the maxillary palps ( Figs 44A–B View FIGURE 44 ). The adult male has a tab-like vesicle on sternum-9 ( Fig. 40C View FIGURE 40 ), an anterior epiproct prong that is hooded at its apex ( Figs 41A–E View FIGURE 41 ), a basal plate of tergum-10 with well-developed lobes and a weak median strut ( Figs 41A–E View FIGURE 41 ). Additionally, the male has dorsally directed basal cercal processes ( Figs 41A, D View FIGURE 41 ). The subgenital plate of the female is moderately produced posteriorly ( Figs 40E View FIGURE 40 ; 42A–B View FIGURE 42 ).

The Oemopteryx vanduzeea Group

The Oemopteryx vanduzeea Group is represented only by O. vanduzeea . The larvae of this group have an acute nipple-like projection on the apex of sternum-9 ( Figs 48F–G View FIGURE 48 ) and lack setae on the cercus ( Fig. 48B View FIGURE 48 ), antenna ( Fig. 48C View FIGURE 48 ) and maxillary palp ( Figs 49A–B View FIGURE 49 ). The adult male has a tab-like vesicle on sternum-9 ( Fig. 45C View FIGURE 45 ), an anterior epiproct prong that is flat and undivided ( Figs 46A–B, 46D–E View FIGURE 46 ), a basal plate of tergum-10 with well-developed lobes and a weak median strut ( Figs 46A–C View FIGURE 46 ). Additionally, the male has long, anteriorly directed basal cercal processes that are bent at mid-length ( Figs 46A–B, 46D–E View FIGURE 46 ) and the apex of sternum-9 is acute anterodorsally. The subgenital plate of the female is moderately produced posteriorly ( Figs 45E View FIGURE 45 , 47A–B View FIGURE 47 ) and sternum-9 has an acute medial projection ( Figs 45E View FIGURE 45 , 47A View FIGURE 47 ).