Oemopteryx leei Baumann & Kondratieff, 2009

Oemopteryx leei Baumann & Kondratieff, 2009 View in CoL

( Figs 40–44 View FIGURE 40 View FIGURE 41 View FIGURE 42 View FIGURE 43 View FIGURE 44 )

Headwater Willowfly

Oemopteryx leei Baumann & Kondratieff, 2009a: 199 View in CoL . Holotype male (CAS), Willow Creek , Humboldt Co., California, USA.

Distribution. USA.—CA, OR ( Baumann & Kondratieff 2009a; DeWalt et al. 2024) ( Fig. 39 View FIGURE 39 )

Material examined. USA.— California: Humboldt Co., Oil Creek headwaters, [Mattole Rd.], 40.49400, - 124.30800, 2 May 2011, B. Kondratieff, J. Sandberg, 4M, 2F ( CSUIC) GoogleMaps ; Willow Creek, at Hwy 299, mile 29.54, [40.90443, -123.74335], 14 April 2006, L. Lee, 9M, 4F ( CSUIC) GoogleMaps ; [ UT to Butte Creek], Butte Creek Access Rd, 1.8 mi S Hwy 36, 40.41982, -123.68350, 2 May 2011, B. Kondratieff, J. Sandberg, 32M, 8F, 5L ( CSUIC) GoogleMaps . Siskiyou Co., Etna Creek, Sawyers Bar Rd. , 41.41157, -122.97366, 14 May 2016, C. Kerst, 1M ( CSUIC) GoogleMaps . Oregon: Linn Co., [Two Girls Creek], Two Girls Peak, Willamette National Forest , [44.34066, -122.29390], 25 August 2005, A. Moldenke, VerLinden, 4M, 2F ( CSUIC) GoogleMaps .

Adult male ( Fig. 40A View FIGURE 40 ). Macropterous. Length of forewings 7.3–8.0 mm (n = 10). Length of body 6.0– 7.3 mm (n = 10). General body color brown.

Head. ( Fig. 40A View FIGURE 40 ). Dorsum of head mostly light-brown. Labrum pale anteriorly, brown posteriorly. Anterior frontoclypeus light-brown. Frons with a brown U-shaped marking. Antenna longer than body. Scape, pedicel, and flagella brown. Scape with a distal notch on anterior face. First flagellum subdivided at distal 1/4. Interocellar area uniformly brown, darker than rest of head and slightly depressed. Dark rugosities anterior to lateral ocelli. Pale transverse band posterior to lateral ocelli. Occiput with brown rugosities. Medial areas of the frons, interocellar surface, and occiput covered with fine, pale, clothing hairs.

Thorax ( Fig. 40A View FIGURE 40 ). Pronotum subquadrate, wider than long (length 0.8X width) with posterior width slightly wider than anterior width; light-brown overall with brown rugosities.Disk with irregular brown rugosities.Prosternum lightly sclerotized. Meso- and metathorax dark-brown, heavily sclerotized dorsally and ventrally. Mesonotum with a triangular pale anteromedial spot. Thoracic nota and coxae uniformly covered with sparse, short, fine clothing hairs. Legs light-brown with contrasting pigment. Distal portion of femur with darker pigment. Tibia light-brown, darker brown on proximal and distal portions; apex of tibiae with 2-stout apical spines. Tarsus light-brown distal segments progressively darker. Legs uniformly covered with dark, short stout setae. Wings hyaline, amber; venation brown; mottling absent. Forewing without costal crossveins between humeral crossvein and apex of the subcostal vein which may be forked.

Abdomen. First abdominal tergite completely pale. Abdominal segments 1–9 lightly covered with short, fine clothing hairs. Terga 2–6 with posterior sublateral patches of stout dark brown setae. Terga 3–7 with intersegmental sublateral membranous bulges. Terga 6–9 pale posteromedially, otherwise terga brown. Sterna 1–9 brown with a pair of sub-lateral brown spots. Sternum-9 with a lightly sclerotized, clavate, tab-like vesicle that is attached to sternum-9 at the anterior margin of the vesicle. ( Fig. 40C View FIGURE 40 ). Sternum-9 elongated into a scooped plate, width subequal from base to apex; apex truncate ( Fig. 41C View FIGURE 41 ); plate with numerous long setae on dorsal and ventral surfaces ( Figs 41A, 41D View FIGURE 41 ); plate covering sternum-10 ventrally and extending beyond.

Terminalia ( Figs 41A–E View FIGURE 41 ). Abdominal segment-10 nested within segment-9. Anterior margin unsclerotized. Tergal sclerite-10 lightly sclerotized with a medial cleft, paired anterior processes absent ( Fig. 41C View FIGURE 41 ). Cercus 5–6 segmented, excluding vestigial apical segment ( Figs 40C View FIGURE 40 , 41A, 41D View FIGURE 41 ). Basalcercal process dorsally directed with an acutely pointed posteriorly oriented apex and covered dorsally with sensilla basiconica and long socketed setae; basalcercal process much shorter than cercus ( Figs 41A, 41D View FIGURE 41 ). Basal plate of tergum-10 bulbous with 2-hemispherical lobes divided by a median furrow and bearing long socketed setae ( Figs 41A–E View FIGURE 41 ). Lateral struts present ( Fig. 41A View FIGURE 41 ), median strut present (not shown). Basal bulb ( Figs 41A–B View FIGURE 41 ), glabrous, oval, bulbous, moderately sclerotized and with an inner bulb bearing a small hollow stalk, which terminates at a pore at the apical 1/4 on the ventral face of the anterior epiproct. Anterior epiproct prong fused to basal bulb, broadly spatulate with sinuous lateral margins and a hood-like tip ( Figs 41A–E View FIGURE 41 ). Posterior epiproct prong closely appressed to anterior prong, lightly sclerotized, divided near apex with dorsal and ventral processes. Ventral process thin and cylindrical with posteriorly directed plate-like setae and long sensillae ( Figs 41A–B, 41D–E View FIGURE 41 ). Dorsal process pouch-like, armed with posteriorly directed spine-like setae with an apical sleeve containing an internal filament ( Figs 41A–B, 41D–E View FIGURE 41 ). Internal filament eversible and apparently composed of 2-strands that are twisted, fused and hooked near the apex. Filament(s) visible inside basal bulb. Paraprocts ( Fig. 41A View FIGURE 41 ) subdivided into 2-parts, symmetrical anterior paraprocts and asymmetrical multi-lobed posterior paraprocts. Anterior paraproct posterior to cercus, base triangular, well sclerotized with a small, lightly sclerotized finger-like mediodorsal projection. Posterior paraprocts with 4-prongs, variously fused. Left outer prong flattened with a truncate apex; left outer middle prong flattened, lightly sclerotized, apex spatulate. Left inner middle prong cupped longitudinally, moderated sclerotized, apex truncate. Left inner prong thinner and shorter, moderately sclerotized with a rounded apex bearing 3-spines. Right outer prong lightly sclerotized, flattened, concave posteriorly with lateral flanges and a curved spinous apex. Right outer middle prong moderately sclerotized with a broadly rounded apex; right inner middle prong twisted with a membranous filamentous apex; right inner prong thinner and shorter, moderately sclerotized, apex rounded bearing 4-stout spines.

Adult female ( Fig. 40B View FIGURE 40 ). Macropterous. Length of forewings 8.5–8.9 mm (n = 10). Length of body 7.3–8.5 mm (n = 10). General body color brown. Overall appearance similar to male. Wings hyaline, amber; venation brown; mottling absent. Forewing without costal crossveins between humeral crossvein and apex of the subcostal vein which may be forked ( Fig. 40D View FIGURE 40 ). AA1 vein of forewing with short fine setae ≤ 0.5mm ( Fig. 40F View FIGURE 40 ). Dorsum of abdomen lightly sclerotized, otherwise unmodified. Venter of abdomen similar to male. Sternum-8 lightly to moderately sclerotized anteriorly ( Fig. 40E View FIGURE 40 ). Subgenital plate moderately produced posteriorly with a narrow Ushaped notch medially ( Figs 40E View FIGURE 40 ; 42A–B View FIGURE 42 ); moderately sclerotized ( Fig. 40E View FIGURE 40 ). Sternum-9 parabolic, produced just beyond the apex of abdominal segment-10; length of free portion of sternum-9 0.8X basal width; uniformly covered with long setae that become longer posteriorly; lateral margins moderately narrowing to a rounded apex ( Figs 40E View FIGURE 40 ; 42A–B View FIGURE 42 ). Cercus 5–6 segmented, excluding vestigial apical segment ( Figs 40E View FIGURE 40 ; 42A View FIGURE 42 ).

Ovum. Unknown.

Mature larva ( Fig. 43A View FIGURE 43 ). Length of male body 6.4–6.5 mm (n = 2), female body 6.8–7.5 mm (n = 3). General color 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 ( Fig. 43A View FIGURE 43 ). Dorsum of head brown with indistinct darker brown maculations variously developed. Antelabrum and postlabrum brown with 2-anterolateral pale spots; anterior margin with a dense brush of golden setae. Anterior frontoclypeus brown. Interocellar area brown. Occipital area brown with indistinct, irregular brown rugosities. Eyes with pigmented ommatidia sometimes reduced, not reaching eye margins. A single long seta both anterior and posterior to eyes. Antennal scape, pedicel and flagella brown; dorsobasal apically inserted setae present up to segment-15 ( Fig. 43C View FIGURE 43 ); antenna slightly shorter than body ( Fig. 43A View FIGURE 43 ).

Maxilla ( Figs 44A–B View FIGURE 44 ). Lacinia triangular with a straight inner margin. Lacinia with 2-apical, cupped teeth and weakly developed denticles on ventral face; actual number difficult to discern due to wear. Apical teeth subequal in length; length of apical teeth relative to palm length difficult to discern due to wear. Inner palm margin with 10–11 stout socketed marginal setae below apical teeth; first setae below apical teeth robust; a patch of hair like acanthae present below apical teeth; acutely pointed sensilla basiconica below apical teeth and on inner palm margin near the middle. Basal 1/3 of palm with a cluster of>10 thin dorsal setae. 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 marginal row of long setae below apical setae extends about 2/3 to base. Length of galea, including apical setae, 1.1X length of lacinia; width of galea subequal to lacinia width. Maxillary palp with 5-segments; 2.2X length of lacinia; palp with sensilla basiconica developed on the apical and lateral margins of each segment.

Mandible. Right mandible ( Fig. 44C View FIGURE 44 ) bicuspid, outer cusp with 3-teeth, inner cusp with 1-tooth. Molar pad adorned with marginal rows of rounded acanthae (length 2.0X width). Palm dorsum with 8–9 dorsal sensillae adjacent to molar pad (requires focusing through the mandible) ( Fig. 44C View FIGURE 44 circle inset); proximal basal corner with a marginal patch of 3–4 hair-like, branched setae. Ventro-apical setal patch extending from outer cusp to beyond the inner cusp basally (indicated by dotted line in Fig. 44C View FIGURE 44 ) Left mandible ( Fig. 44D View FIGURE 44 ) bicuspid, outer cusp with 5- teeth, inner cusp with 1-broad tooth. Molar pad with marginal rows of rounded acanthae and long pointed acanthae (length 5.0X width). Palm dorsum with 8–9 dorsal sensillae adjacent to molar pad (requires focusing through the mandible) ( Fig. 44D View FIGURE 44 circle inset); the proximal basal corner with a marginal patch of 3–4 hair-like, branched setae. Ventro-apical setal patch extending from outer cusp to middle of the inner cusp (indicated by dotted line in Fig. 44D View FIGURE 44 , square inset).

Thorax ( Fig. 43A View FIGURE 43 ). Pronotum wider posteriorly; light-brown with faint rugosities; Length of forewing pad 3.3X width; length of hindwing pad 1.8X 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. 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, wider than long (length 0.9X width). Metathoracic basisterna with a medial patch of light-brown spicules and a pair of furcasternal pits. Femur and tibia generally light-brown and with a fringe of silky setae (not shown); length of femoral setae about ½ the width of the femur; length of tibial setae longer than tibial width. Anterior and posterior faces of the femur with scattered short stout setae. Tibial callus darkened ( Fig. 43D View FIGURE 43 ). Tarsus with a sparse dorsal fringe of silky setae (not shown); tarsus light-brown to brown. Venter of tibia and tarsus with scattered short stout setae.

Abdomen. Dorsum of abdomen uniformly brown ( Fig. 44E View FIGURE 44 ). Terga with a sparse posterior row of short, stout sensillae and pair of longer submedial stout sensillae anterior to those. Posterior margins of terga 8–10 with a pair of thin, erect, submedial setae. Venter of abdomen brown or with a purple hue; sterna 1–8 with light-brown spicules. Sternum-9 with an elongate plate (male = length 1.6X width ( Fig. 43F View FIGURE 43 ); female = length 1.6X width ( Fig. 43G View FIGURE 43 )); plate width relative to sternal width (male = 0.75X; female = 0.75X). Both male and female with plate narrower basally, widest at posterior margin of sternum-9; posterolateral margins convex, evenly narrowing towards apex; apex broadly rounded. Plates of both males and females with stout setae begin at basal 1/5, becoming denser towards apex. Cercus uniformly brown; dorsobasal apically inserted setae present up to segment-15 ( Fig. 42B View FIGURE 42 ); cercus longer than body ( Fig. 43A View FIGURE 43 ).

Diagnosis. Oemopteryx leei is defined in the adult male by the anterior prong of the epiproct having a hood-like tip and the basal cercal processes being dorsally directed with a posteriorly oriented, pointed apex. The female is distinguished by having a subgenital plate with a narrow U-shaped notch medially. The larvae are unique in having long hair-like sensillae on distal margins of segments 3–4 of the maxillary palps.

Biological notes. Oemopteryx leei is presently known from the three EPA Level III ecoregions (Coast Range, Klamath Mountains, and Cascades) in northern California to west-central Oregon. Elevations of collection locations range between 447 m to 1411 m ASL. Based on known records O. leei appears to be allopatric with O. vanduzeea , which occurs in the Central California Foothills/Coastal Mountains, Sierra Nevada, Cascades , and Eastern Cascades Slopes and Foothills Level III ecoregions in California, though some range overlap could occur in the Cascades Level III ecoregion. Available records indicate adults are generally active from mid-April to mid-May; however, one record from Two Girls Peak in Willamette National Forest, Oregon was collected 25 August. Larvae have been collected from only one location with a drainage area of 1.6 km 2. Nothing is known regarding this taxon’s life history. A conservation rank of G3 was calculated for this species indicating a moderate risk of extinction because of its relatively restricted range and few known populations (NatureServe 2020).

The O. vanduzeea Group