Rhyacophila loeffleri, Valladolid & Waringer, 2023

Valladolid, Maria, Arauzo, Mercedes, Coppa, Gennaro, Reding, Jean-Paul G., Dorda, Beatriz A. & Rey, Isabel, 2025, The Rhyacophila fasciata Species Complex (Trichoptera: Rhyacophilidae) in France and Switzerland, with description of a new species, Rhyacophila caussensis Valladolid & Coppa sp. nov. from France, based on morphological, genetic and ecological evidence, Zootaxa 5692 (3), pp. 401-445 : 424-435

Rhyacophila loeffleri

MALE

Biometrics: Body length (distance from front of head to distal edge of segment IX): 9.2–10.0 mm (x̄ = 9.6, n = 3), forewing 11.3–12.7 mm (x̄ = 12.0, n = 3), hind wing 10.2–11.4 mm (x̄ = 10.6, n = 3).

Genitalia ( Figs 21 , 24 ): 2nd segment of each inferior appendage ( Figs 21A , 24a ) with posterior edge slightly convex in central area, ventral edge straight or slightly convex, ~ 2.1 times longer that dorsal edge; apicodorsal vertex of 2nd segment ~ 135° and angled, apicoventral angle ~ 45°, projecting as thick lobe tapering to round apex.

Parameres in ventral view curved posteromesad in distal half ( Figs 21 BV, p; 24c). In lateral view ( Figs 21 BL, 24d) each constricted 1/3 distance beyond base, dilated at middle, with round dorsal and straight or slightly convex ventral margins respectively; along posterior midventral margin two rows with three long, thick spines, pointing outward; midlateral surface with spicules or setae, from middle posteroventral to posterodorsal edges, decreasing on size from ventral to dorsal edges. Aedeagus (phallicata) in lateral view ( Fig. 21 CL) with anterodorsal margin and posterior corner of dorsal concavity hooked anterad, apical edge of aedeagus straight or slightly convex; ventral lobe of aedeagus in ventral view triangular ( Fig. 21 BV, vl), in lateral view vertical edge convex, posteroventral angle almost 90º ( Fig. 21 CL). In dorsal view posterior edges of lateroventral lobes of phallus apically straight or slightly convex, apicolateral margins round ( Fig. 21 CD, lvl).

Apicodorsal lobe of segment IX in dorsal view almost circular, slightly dilated subapicolaterally ( Figs 21 DD, al; 24b), with small apicomesal excision in some specimens; preanal appendages ( Fig. 21 DD, pa) rectangular, 3/4 as long as apicodorsal lobe, pointed subapically and posterior edges convex. In ventral view, apical band diamond shaped ( Fig. 21 DV, ab), almost as long as wide, its posterior arms convergent posterad, rounded apically, its non-sclerotized mesal area oval ( Fig. 21 DV, va), anal sclerites triangular, posterior edges straight or slightly concave ( Fig. 19 DV, as).

FEMALE

Biometrics: 1 specimen. Body length (distance from front of head to distal edge of segment VIII): 10.9 mm, forewing 12.8 mm, hind wing 11.3 mm.

Genitalia ( Figs 22 , 27 ): In lateral view ( Figs 22L , 27L ), posterior margin of segment VIII valves on each side triangular, with a dorsolateral projection, posterodorsal and posteroventral margins straight or slightly concave. In dorsal view ( Figs 22D , 27D ), with indentation between segment VIII valves enclosed by pair of small dorsolateral suboval projections, with rounded apical and subapical corners, delimiting oval space. In ventral view ( Figs 22V , 27V ) segment VIII valves forming two elongate sclerites, concave, diverging and separated basally; intersegmental membrane with pair of dark, ovoid or slightly elongate sclerites.

Diagnosis of males of Rhyacophila septentrionis , R. loeffleri and R. fasciata

Genitalia: In R. septentrionis , ( Fig. 23a ) the posterior edge of the second segment of each inferior appendage is slightly concave in the dorsal area and the ventral edge is about 2.2 times longer than dorsal edge. In R. loeffleri ( Fig. 24a ) the posterior edge of the second segment of each inferior appendage is slightly convex in the middle and ventral edge is about 2.1 times longer than dorsal edge. In R. fasciata , the posterior edge of the second segment of each inferior appendage is slightly concave dorsally and convex ventrally and the ventral edge is less than 1.8 times longer that dorsal edge ( Fig. 25a ).

In R. septentrionis the posterior edge of aedeagus is straight and projected posteroventrad in a small ventral apex in lateral view ( Fig. 19 CL); the ventral lobe of aedeagus is semicircular with the apex pointed ( Figs 19 BV, vl; 23c), in lateral view a small projection in posteroventral angle ( Fig. 19 CL); posterior edges of lateroventral lobes of phallus are convex; the apicolateral margins are rounded. In R. loeffleri the posterior edge of aedeagus is straight or slightly convex ( Fig. 21 CL); the ventral lobe of aedeagus is triangular ( Figs 21 BV, vl; 24c), in lateral view angled, almost 90º ( Fig. 21 CL); posterior edges of lateroventral lobes of phallus are straight or slightly convex; the apicolateral margins are rounded ( Fig. 21 CD, lvl). In R. fasciata the posterior edge of aedeagus is straight, projected posteroventrad, and rounded at posteroventral apex ( Valladolid et al. 2021, fig. 12CL); the ventral lobe of aedeagus is subtriangular and round posteroventrally ( Fig. 25c ); the lateroventral lobes of phallus are straight, its posterior edges convex, apicolateral margins rounded.

In R. septentrionis the apicodorsal lobe of segment IX in dorsal view ( Figs 19 DD, al; 23b) is dilated subapicolaterally, with a small apicomesal excision; the preanal appendages ( Fig. 19 DD, pa) are round; the apical band in ventral view ( Fig. 19 DV, ab) is V-shaped with its posterior arms almost parallel; the non-sclerotized mesal area ( Fig. 19 DV, va) is oval, narrow; the anal sclerites ( Fig. 19 DV, as) are concave apically. In R. loeffleri the apicodorsal lobe of segment IX in dorsal view ( Figs 21 DD, al; 24b) is slightly dilated subapicolaterally, with small apicomesal excision in some specimens; the preanal appendages ( Fig. 21 DD, pa) are rectangular; the apical band in ventral view ( Fig. 21 DV, ab) is diamond shaped with its posterior arms converging posterad; the non-sclerotized mesal area oval ( Fig. 21 DV, va), the anal sclerites are straight or slightly concave apically ( Fig. 21 DV, as). In R. fasciata the apicodorsal lobe of segment IX in dorsal view ( Fig. 25b ) is dilated subapicolaterally, almost round, with maximum with in the posterior third and a small apicomesal excision in some specimens; the preanal appendages ( Valladolid et al. 2021, fig. 12DD, pa) are round, convex laterally; the apical band in ventral view ( Valladolid et al. 2021, fig. 12DV, ab) 1.8 times as long as wide, its posterior arms widely separate and straight; the non-sclerotized mesal area ( Valladolid et al. 2021, fig. 12DV, va) is heart-shaped and with a wider posteromesal excision; the anal sclerites ( Valladolid et al. 2021, fig. 12DV, as) are truncated apically.

In R. septentrionis the parameres in lateral view ( Figs 19 BL, 23d) each without spines on its midventral margin, with few long, thick spines on its lateroventral area; the midlateral surface is covered by fine spicules or setae from middle to ventral edge, absent in middle anteroventral and posterodorsal edges. In R. loeffleri the parameres in lateral view ( Figs 11 BL, 24d) each with rounded dorsal margin and straight or slightly convex ventral margin, with two rows of three long, thick spines on midventral margin; the midlateral surface covered with spicules or setae, from middle posteroventral to posterodorsal edges, decreasing on size from ventral to dorsal areas. In R. fasciata the parameres in lateral view ( Fig. 25d ; Valladolid et al. 2021, fig. 12BL) are convex basally, with almost parallel dorsal and ventral margins in central area (S-shape), each has two rows of long, thick spines on the posterior midventral margin, each row with more than three spines pointing laterad; the midlateral surface has sparse fine setae from the middle of the anteroventral edge to the posterodorsal edge, covering most of apex, but absent in the middle anteroventral and posterodorsal edges.

Diagnosis of females of Rhyacophila septentrionis , R. loeffleri and R. fasciata

Genitalia: In R. septentrionis lateral view ( Figs 20L , 26L ) each of the segment VIII lateral valves are triangular, truncate posteriorly, with a small scission in the middle, and a dorsolateral projection. In R. loeffleri lateral view ( Figs 22L , 27L ), each of the segment VIII lateral valves triangular, with a dorsolateral projection, posterodorsal and posteroventral margins straight or slightly concave. In R. fasciata lateral view ( Fig. 28L ; Valladolid et al. 2021, fig. 13L) each of the segment VIII lateral valves is quadrate with an apicodorsal projection; the upper posterior margin is nearly vertical and with an irregular edge with one or two posterior sinuosities ( Valladolid et al. 2021, figs 13La, 13Lb), the posteroventral margin is slightly concave sub-basally and straight or convex distally, in some specimens slightly indented posteriorly, the upper posterior margin and the posteroventral margin meet at a round, obtuse angle.

In R. septentrionis dorsal view ( Figs 20D , 26D ), the indentation between the segment VIII valves is nearly enclosed by a pair of triangular apicodorsal projections, with rounded apical and subapical corners, delimiting an oval space. In R. loeffleri dorsal view ( Figs 22D , 27D ), the indentation between segment VIII valves is enclosed by a pair of suboval apicodorsal projections, with rounded apical and subapical corners, delimiting an oval space. In R. fasciata dorsal view ( Fig. 28D ; Valladolid et al. 2021, fig. 13Da), the indentation between the segment VIII valves is nearly enclosed by a pair of thick apicodorsal projections delimiting an oval space; a small projection occurs anteromesally in some specimens.

In R. septentrionis ventral view ( Figs 20V , 26V ), the segment VIII valves form two elongate sclerites converging basally, their lateral margins are concave; the intersegmental membrane with a pair of dark, slightly elongate sclerites. In R. loeffleri ventral view ( Figs 22V , 27V ), the segment VIII valves form two elongate sclerites, with lateral margins concave; the intersegmental membrane with a pair of dark, ovoid or slightly elongate sclerites. In R. fasciata ventral view ( Fig. 28V ; Valladolid et al. 2021, fig. 13V), the segment VIII valves form two elongate sclerites that are narrowly separated basally, the mesal margins are parallel in their basomesal 1/4 and straight in their apicomesal 3/4, their lateral margins convex; the intersegmental membrane with a pair of dark, ovoid or slight elongate sclerites.

Diagnosis of larvae of Rhyacophila septentrionis , R. loeffleri and R. fasciata

Head: In R. septentrionis ( Fig. 30a ) the cephalic capsule in dorsal and dorsolateral view is dark brown, with anterior third and posterior areas pale; the pair of dark brown patches outside the posterior portion of the frontoclypeus are more nearly triangular, with paler spots with dark borders inside ( Fig. 30b ); the setae S15 and S16 ( Fig. 29a ) are located in the centre of pale circular areas, contrasting with the surrounding darker area ( Fig. 30a ), setae S19 is located in the limit of the dark anterior area and broad pale posterior area; in lateral view ( Fig. 30c ) an almost oval brown area with dark spots in posterior third and dorsally. In R. loeffleri ( Fig. 31a ) the head is generally pale with dark areas and spots; the pair of dark brown patches outside the posterior portion of the frontoclypeus are more or less semicircular around the juncture of frontal and coronal sutures, extending forward parallel to frontal sutures, inside each patch there are no spots in the darker anterior extension, in the outermost edge of the light brown posterior portion there is one row of dark spots aligned parallel to the suture and groups of spots outside the row ( Fig. 31b ); the setae S15, S16 and S19 ( Fig. 29a ) are connected by a large, pale area ( Fig. 31a ); in lateral view an oval brown with darker and paler spots in dorsal and ventral areas respectively ( Fig. 31c ). In R. fasciata ( Fig. 32a ), the two-thirds of posterior dorsal area of head are light brown; the pair of dark brown patches outside posterior edge of frontal suture have the shape of open wings, with dark spots inside ( Fig. 32b ); the setae S15, S16 and S19 ( Fig. 29a ) are located in the centre of pale circular areas, contrasting with the surrounding darker area ( Fig. 32a ); in lateral view ( Fig. 32c ) an oval brown area with dark spots.

Thorax: In R. septentrionis ( Figs 33a, 33b ) the black band in the anterolateral angle extends posterad as a brown band laterally, connected with the broad, black band of the posterolateral margin ( Fig. 33b ); on posterior half three dark areas or dark base with darker mesal stripe with two lines of pale spots inside, two pale brown spots with dark borders anterolateral and posterolaterally to seta S6, circular and elongate respectively; the posterior area with two-three lines of darkly-bordered pale brown spots of different shapes and parallel to posterior border ( Fig. 33b ); the anterior margin with a line of black spots near anterolateral angle, light brown in middle; mesal area of posterior marginal band of each sclerite brown anteriorly and reddish brown posteriorly ( Fig. 33b ). In R. loeffleri ( Figs 34a, 34b ) the narrow black band in the anterolateral angle extends posterad as a brown band laterally, connected with the broad, black band of the posterolateral margin; on posterior half three darker areas connected by a dark band ( Fig. 34a ), the median dark stripe is truncate anteriorly and wider than posteriorly and with its lateral edges slightly concave or straight; each triangular posterolateral area has two or three transverse rows of circular-oval pale brown spots with darker borders and a bigger oval spot near the diagonal lateral edge; the posterior marginal band at mid-height brown and reddish brown anteriorly and posteriorly, respectively ( Fig. 34b ). In R. fasciata ( Figs 35a, 35b ) the narrow black band in each anterolateral angle extends posterad to join with the broad, black band of the posterolateral margin; on posterior half three darker areas connected ( Fig. 35a ), the median dark stripe is convex anteriorly and with its lateral edges slightly convex; each triangular posterolateral area has two or three transverse rows of circular brown spots with dark borders but no bigger spot near the diagonal lateral edge; the posterior marginal band at mid-height dark brown or black posteriorly ( Fig. 35b ).

Abdomen: In R. septentrionis ( Figs 33c, 33d ) the abdominal segments have two stripes of oval spots, separated by a central triangular pale area, two stripes of anterolateral triangular pale spots, connected by semicircular bars in central area, and two semicircular pale bars in posterolateral angles. In R. loeffleri ( Figs 34c, 34d ) the abdominal segments have two stripes of anterolateral circular pale spots, connected by V-shape bars in central area, and two central stripes of oval darker spots, with pale bars anteriorly. In R. fasciata ( Figs 35c, 35d ) the abdominal segments have two stripes of rectangular darker spots, surrounded anterior, lateral and posteriorly by paler stripes that connect with paler stripes of anterior and lateral edges, and anterolaterally, some irregular shaped paler spots.

Diagnosis of pupae of Rhyacophila septentrionis , R. loeffleri and R. fasciata

Abdomen: In R. septentrionis ( Fig. 36 ) the paired anterior hook plates are pedunculated, almost circular, and elongate on AVII, and the pair of small flat hook plates AIII with 10–15 spines; the paired posterior hook plates PIII–PV are almost circular. In R. loeffleri ( Fig. 37 ) the paired anterior hook plates are almost circular and the pair of small flat plates AIII in females each have 2–3 spines, AIII are not present in males; the paired posterior hook plates are circular except for oval PIV. In R. fasciata ( Fig 38 ), the paired anterior hook plates AIV-AVII are palmate and the pair of small flat anterior plates AIII are without spines; the paired posterior hook plates PIII–PV are all slightly transversely oval (length: width = 1: 1.3).

Figures

FIGURE 29. Setae (S) and sensory pits (P) of the head and thorax of Rhyacophila larvae. 29a, head, dorsal; 29b, prothorax, right sclerite, dorsal (from Williams & Wiggins 1981).

FIGURES 21–22. Male and female genitalia of Rhyacophila loeffleri Valladolid & Waringer 2023, respectively. 21, male: 21A, 2nd segment of left inferior appendage, left lateral; 21BV, 21BL, parameres: 21BV, parameres (p) and ventral lobe of aedeagus (phallicata) (vl), ventral; 21BL, left paramere, left lateral. 21CL, 21CD, aedeagus (phallicata) and lateroventral lobes: 21CL, aedeagus, left lateral; 21CD, aedeagus and its lateroventral lobes (lvl), dorsal. 21DD, apicodorsal lobe of segment IX (al) and preanal appendages (pa); 21DV, segment X, ventral ab = apical band, as = anal sclerites, va = non-sclerotized ventral area. 22, female segments VIII–XI: 22L, left lateral; 22D, dorsal; 22V, ventral. Scale bars: unlabelled = 1 mm; ● = 0.5 mm; * = 200 μm.

FIGURES 23–25. Males of Rhyacophila septentrionis McLachlan 1865, Rhyacophila loeffleri Valladolid & Waringer 2023 and Rhyacophila fasciata Hagen 1859. 23, male of R. septentrionis: 23a, 2nd segment of left inferior appendage, left lateral; 23b, apicodorsal lobe of segment IX and preanal appendages, dorsal; 23c, parameres and ventral lobe of aedeagus (phallicata), ventral; 23d, left paramere, left lateral. 24, male of R. loeffleri: 24a, 2nd segment of left inferior appendage, left lateral; 24b, apicodorsal lobe of segment IX and preanal appendages, dorsal; 24c, parameres and ventral lobe of aedeagus (phallicata), ventral; 24d, left paramere, left lateral. 25, male of R. fasciata: 25a, 2nd segment of left inferior appendage, left lateral; 25b, apicodorsal lobe of segment IX and preanal appendages, dorsal; 25c, parameres and ventral lobe of aedeagus (phallicata), ventral; 25d, left paramere, left lateral. Scale bars: Figures 23a–c, 24a–c, 25a–c = 0.5 mm, Figures 23d, 24d, 25d = 200 μm.

FIGURES 19–20. Male and female genitalia of Rhyacophila septentrionis McLachlan 1865, respectively. 19, male: 19A, 2nd segment of left inferior appendage, left lateral; 19BV, 19BL, parameres: 19BV, parameres (p) and ventral lobe of aedeagus (phallicata) (vl), ventral; 19BL, left paramere, left lateral. 19CL, 19CD, aedeagus (phallicata) and lateroventral lobes: 19CL, aedeagus, left lateral; 19CD, aedeagus and its lateroventral lobes (lvl), dorsal. 19DD, apicodorsal lobe of segment IX (al) and preanal appendages (pa); 19DV, segment X, ventral ab = apical band, as = anal sclerites, va = non-sclerotized ventral area. 20, female segments VIII–XI: 20L, left lateral; 20D, dorsal; 20V, ventral. Scale bars: unlabelled = 1 mm; ● = 0.5 mm; * = 200 μm.

FIGURES 26–28. Females of Rhyacophila septentrionis McLachlan 1865, Rhyacophila loeffleri Valladolid & Waringer 2023 and Rhyacophila fasciata Hagen 1859. 26, female segments VIII–XI of R. septentrionis: 26L, left lateral; 26D, dorsal; 26V, ventral. 27, female segments VIII–XI of R. loeffleri: 27L, left lateral; 27D, dorsal; 27V, ventral. 28, female segments VIII–XI of R. fasciata: 28L, left lateral; 28D, dorsal; 28V, ventral. Scale bar: 1 mm.

FIGURES 11–12. Male and female genitalia of Rhyacophila sociata Navás 1916, respectively. 11, male: 11A, 2nd segment of left inferior appendage, left lateral; 11BV, 11BL, parameres: 11BV, parameres (p) and ventral lobe of aedeagus (phallicata) (vl), ventral; 11BL, left paramere, left lateral. 11CL, 11CD, aedeagus (phallicata) and lateroventral lobes: 11CL, aedeagus, left lateral; 11CD, aedeagus and its lateroventral lobes (lvl), dorsal. 11DD, apicodorsal lobe of segment IX (al) and preanal appendages (pa); 11DV, segment X, ventral ab = apical band, as = anal sclerites, va = non-sclerotized ventral area. 12, female segments VIII–XI: 12L, left lateral; 12D, dorsal; 12V, ventral. Scale bars: unlabelled = 1 mm; ● = 0.5 mm; * = 200 μm.

FIGURES 30–32. Larvae of Rhyacophila septentrionis McLachlan 1865, Rhyacophila loeffleri Valladolid & Waringer 2023 and Rhyacophila fasciata Hagen 1859. 30, head of Rhyacophila septentrionis: 30a, 30b, dorsal; 30c, rigth lateral. 31, head of Rhyacophila loeffleri: 31a, 31b, dorsal; 31c, right lateral. 32, head of Rhyacophila fasciata: 32a, 32b, dorsal; 32c, right lateral.

FIGURES 33–35. Larvae of Rhyacophila septentrionis McLachlan 1865, Rhyacophila loeffleri Valladolid & Waringer 2023 and Rhyacophila fasciata Hagen 1859. 33, prothorax and abdominal segment of Rhyacophila septentrionis: 33a, prothorax; 33b, right hemisclerite; 33c, 33d, abdominal segment III. 34, prothorax and abdominal segment of Rhyacophila loeffleri: 34a, prothorax; 34b, right hemisclerite; 34c, 34d, abdominal segment III. 35, prothorax and abdominal segment of Rhyacophila fasciata: 35a, prothorax; 35b, right hemisclerite; 35c, 35d, abdominal segment III.

FIGURES 36–38. Paired abdominal hook plates of male pupa. 36, Rhyacophila septentrionis McLachlan 1865. 37, Rhyacophila loeffleri Valladolid & Waringer 2023. 38, Rhyacophila fasciata Hagen 1859. 36l– 36r, 37l– 37r, 38l– 38r = left and right hook plates, respectively. A = anterior hook plates, dorsal, P = posterior hook plates, dorsal; III–VII = abdominal terga III through VII, dorsal. Scale bars: 50 μm.