We are glad to name this new species after Prof. Ralph W. Holzenthal of the University of Minnesota, as homage to his bright career of research and teaching, motivating several generations of new insect biodiversity professionals.

Holotype , male, VENEZUELA: Bolívar, Parque Nacional Canaima, Gran Sabana, Río Tarotá, 5°49'15.0"N, 61°25'04.0"W, 1,324 m a.s.l., 14.iii.2007, leg. Azevedo, CAS; Hamada, N. (INPA). Paratype, female, same data as holotype (INPA).

Head and pronotum pale reddish brown (Figs 1A, C, 2A, C), with yellowish elements on the head, especially on antennae and labrum. Body and wings generally pale reddish brown, wings unpatterned, thus resembling C. neblinensis Contreras-Ramos and C. wanningeri (Figs 1B, D, 2B, D). Male genitalia similar to C. wanningeri; however, in the new species the gonostylus 9 has a slightly projected and convex apex (Figs 5A, C, 6A), whereas C. wanningeri has a strongly extended and narrow apex (Figs 5B, D, 6B); C. neblinensis has a subclavate and unmodified gonostylus 9 (Contreras-Ramos 1998: fig. 26A, B). Shape of gonostyli 10 is also diagnostic. In the new species these are strongly sclerotized, almost parallel to each other, subtriangular, bluntly pointed, and caudally straight (Figs 5A, C, 6C); while they are strongly sclerotized, close to each other, convergent, and bluntly pointed in C. wanningeri (Figs 5B, D, 6D); and semi-membranous, widely separated, and papilliform in C. neblinensis (Contreras-Ramos 1998: fig. 26C). Gonostyli 10 of C. ralphi sp. nov. resemble those from C. crossi; however, the latter species is easily separated from the new one by its dark brown body and darkly patterned wings (Contreras-Ramos 2002: fig. 6). Females may be distinguished by the unpatterned pale reddish brown color (Figs 1C, 2C), and by the arrangements of the mandibular dentition (Fig. 3C), with the three basal teeth close to each other, and basal tooth smaller than the second and third ones; also with an inner predental concavity and moderately separated first and second teeth in C. wanningeri (Fig. 3D), and with basal tooth larger than the second and third teeth in C. neblinensis (Contreras-Ramos 1998: fig. 26F).

Figure 1. 

Dorsal habitus of Corydalus spp. A holotype of C. ralphi sp. nov., male B holotype of C. wanningeri Contreras-Ramos & von der Dunk, male C paratype of C. ralphi sp. nov., female D paratype of C. wanningeri Contreras-Ramos & von der Dunk, female. Scale bar: 1 cm.

Figure 2. 

Head and pronotum of Corydalus spp., dorsal view. A holotype of C. ralphi sp. nov., male B holotype of C. wanningeri Contreras-Ramos & von der Dunk, male C paratype of C. ralphi sp. nov., female D paratype of C. wanningeri Contreras-Ramos & von der Dunk, female. Scale bar: 1 mm.

Male measurements: Head width 9.26 mm; mandible length 7.4 mm; antenna length 29.3 mm; forewing length 47.1 mm; hindwing length 40.2 mm; antenna length/forewing length 0.62. Female measurements: Head width 8.9 mm; mandible length 5.35 mm; antenna length 23.4 mm; forewing length 52.5 mm; hindwing length 47.7 mm; antenna length/forewing length 0.44. Body (Fig. 1A, C) pale reddish brown with yellowish elements, especially on head and thoracic pleura.

Head (Figs 2A, C, 3A, C). Pale reddish brown, unpatterned. Vertex infuscated, with three yellow ocelli each surrounded by darkish brown ring. Labrum yellow, with short yellow setae. Clypeal margin darkish brown, lateral projection well developed, subtriangular; medial projection well developed, deeply incised; lateral and median projection close to each other. Male mandible elongate, pale reddish brown with margins dark brown; median tooth longer than in female and narrow; apex curved inwards, bearing three teeth, basal preapical tooth small, subtriangular, and separated from the second preapical tooth, which is closely associated with a well-developed apical tooth. Female mandible same color as male, unmodified; basal preapical tooth small, close to second and third preapical teeth; second preapical tooth smaller than third, apical tooth well developed, darkish brown. Antenna 64–66-segmented, filiform; scape yellow, subquadrangular; pedicel yellow; flagellum yellow, with apical flagellomeres darkish brown. Maxilla darkish brown to yellow; maxillar palpi 5-segmented, palpomeres pale reddish brown with yellow apex. Labium darkish brown to yellow; labial palpi 3-segmented, darkish brown to yellow.

Figure 3. 

Head structures of Corydalus spp. A clypeal margin of holotype of C. ralphi sp. nov., male B clypeal margin of holotype of C. wanningeri Contreras-Ramos & von der Dunk, male C right mandible of paratype of C. ralphi sp. nov., female D right mandible of paratype of C. wanningeri Contreras-Ramos & von der Dunk, female. Scale bar: 1 mm.

Thorax (Figs 1A, C, 2A, C). Pronotum rectangular, nearly 1.45 times longer than wide (length 7.9 mm/ width 5.4 mm), pale reddish brown, unpatterned; densely covered with minute pale brown setae. Mesonotum wider than long, pale reddish brown, unpatterned; densely covered with minute light brown setae. Metanotum similar to mesonotum, but slight narrower. Pteropleura yellow, with basal region of coxa darkish brown; covered with small yellow setae. Legs generally yellow, with small yellow setae, tarsal claws darkish brown.

Wings (Fig. 4). Forewing pale reddish brown, semitranslucent, unpatterned. Venation reddish brown, darker than membrane, densely covered with minute and fine reddish brown setae. Costal field wider at the base, with several simple costal crossvein; pterostigma indistinct. Sc running parallel to RA, and fusing with its apex. Radial field with four crossveins. RP with nine branches, several crossveins present between them. Radiomedial space with four crossveins. M forked bear ¼ of the wing length; MA forked in two main branches (MA₁ and MA₂), MA₁ forked near wing margin, MA₂ unforked; MP unforked; intramedial field with five crossveins. Mediocubital space with six crossveins. Cu forked basally to M fork; CuA with four branches; CuP unforked; intracubital field with one crossvein. Cubitoanal field with two crossveins. A₁ forked apically to Cu fork; field between A₁ and A₂ with one crossvein; A₂ forked basally to A₁ fork; field between A₂ and A₃ with one crossvein; A₃ simple. Hindwing with general aspect similar to forewing. Costal field wider at the base, with several simple costal crossvein; pterostigma indistinct. Sc running parallel to RA, and fusing with its apex. Radial field with three crossveins. RP with nine branches, several crossveins present between them. Radiomedial space with five crossveins, including the elongated, sigmoid 1r-m, with a veinlet linking it to R. M forked bear ¼ of the wing length; MA forked in two main branches (MA₁ and MA₂), MA₁ forked near wing margin, MA₂ unforked; MP unforked; intramedial field with three crossveins. Cu forked near the wing base; CuA with four branches; CuP unforked; intracubital field with one crossvein. Cubitoanal field with one crossvein. A₁ forked apically to Cu fork; field between A₁ and A₂ with one crossvein; A₂ forked near the same level of A₁ fork; field between A₂ and A₃ with one crossvein; A₃ simple.

Figure 4. 

Wings of Corydalus ralphi sp. nov. Scale bar: 5 mm. Abbreviations: A, anal veins; CuA, cubitus anterior; CuP, cubitus posterior; MA, media anterior; MP, media posterior; RA, radius anterior; RP, radial posterior; and Sc, subcosta.

Male genitalia (Figs 5, 6). Tergite 8 rectangular. Sternite 8 rectangular. Medial region of the membrane between sternites 8 and 9 presenting a large, well sclerotized, and subtriangular invagination, 1.5 times wider than long, bearing several minute setae inside and close its opening. Tergite 9 trapezoidal, cephalic V-shaped internal inflection reaching 2/3 of the length of tergite; caudally V-shaped internal inflexion reaching 1/3 of the tergite length. Anal tubercle inconspicuous. Sternite 9 subquadrate, semi-membranous, posterolateral lobes well developed. Gonostylus 9 subclavate, approximately as long as ectoproct, with apex composed by a slightly expanded and convex apex; basal protrusion present, poorly-developed. Gonocoxite 10 slightly convex, anterolateral projections well developed, wider than medial region, subtriangular; gonostylus 10 strongly sclerotized, subtriangular, almost parallel to each other, bluntly pointed, caudally straight. Ectoprocts as long as gonostylus 9, digitiform, basal 1/3 wide, roundly concave; apex slight curved inward. Pregenital sacs absent.

Figure 5. 

Male genitalia of Corydalus spp. A genitalia of holotype of C. ralphi sp. nov., dorsal view B genitalia of holotype of C. wanningeri Contreras-Ramos & von der Dunk, dorsal view C genitalia of holotype of C. ralphi sp. nov., ventral view D genitalia of holotype of C. wanningeri Contreras-Ramos & von der Dunk, ventral view. Scale bar: 1 mm. Abbreviations: ect, ectoproct; Gst 9, gonostylus 9; Gst 10, gonostylus 10; inv, invagination of membrane between segments 8 and 9; S8–9, sternites 8–9; T8–9, tergites 8–9.

Figure 6. 

Structures of male genitalia of Corydalus spp. A gonostylus 9 of C. ralphi sp. nov., latero-caudal view B gonostylus 9 of C. wanningeri Contreras-Ramos & von der Dunk, latero-caudal view C gonocoxites and gonostyli 10 of C. ralphi sp. nov., ventral view D gonocoxites and gonostyli 10 of C. wanningeri Contreras-Ramos & von der Dunk, ventral view. Scale bar: 1 mm. Abbreviations: bp, basal projection of gonostylus 9; Gsx10, gonocoxite 10; Gst10, gonostylus 10.

Female genitalia. Terminalia indistinct. Sternal pouch between abdominal segments 6 and 7, abdominal segments poorly developed. Gonocoxite 8 moderately sclerotized, discontinuous with pleural area, posterior margin mesally semi-membranous, concave. Gonocoxite 9 ovoid, uniformly setose; gonostylus 9 small, semicircular; ectoproct as a small ovoid sclerite, setose.

Venezuela (Bolívar).

Larvae of the new species were collected under rocks near river banks and under the roots of aquatic Cyperaceae in the Tarotá River, Gran Sabana region in Bolívar state, southern Venezuela. Adults were obtained by rearing these larvae in laboratory conditions. Tarotá River has black water and is approximately 20 m wide, with sand bottom and scattered rock and boulders.

Figure 7. 

Habitat and distribution of Corydalus ralphi sp. nov. A South America B Venezuela C Tarotá River, Gran Sabana region, Bolívar state, Venezuela.

Corydalus ralphi sp. nov. is closely related to C. wanningeri, both from the state of Bolívar. The new species was collected in the plateau of the Gran Sabana region, inside the Canaima National Park, whereas C. wanningeri was collected adjacent to the NE limit of Canaima National Park, in a portion of winding road known as La Escalera, highway 10 (connecting Orinoco lowlands with the Gran Sabana plateau in the south), which is a humid slope covered with rain forest, with several brooks and waterfalls (Contreras-Ramos and von der Dunk 2010). It is unknown whether both species are parapatric, or actually sympatric. Both species share similar coloration of wings and body (Fig. 1), nevertheless males of each species may be differentiated by the shape of the gonostylus 9 apex, slightly expanded and convex in C. ralphi sp. nov. (Fig. 6A) and narrow and digitiform in C. wanningeri (Fig. 6B); gonostyli 10 are almost parallel to each other and caudally straight in C. ralphi sp. nov. (Fig. 6C), and apically convergent in C. wanningeri (Fig. 6D); anterior margin of clypeus has medial projection well developed and deeply incised in the new species (Fig. 3A), while it is flat to slightly concave, with shallow incision in C. wanningeri (Fig. 3B). Other characters that help differentiate males of both species are the length of the antennae, reaching ¼ of the wing length in C. ralphi sp. nov. (Fig. 1A), and reaching 4/5 of the wing length in C. wanningeri (Fig. 1B); the new species has modified, yet short mandibles (Fig. 2A), while C. wanningeri has elongated mandibles (Fig. 2B); however, the variation in this trait is still unknown. Females may be separated by the dentition pattern. Corydalus ralphi sp. nov. lacks inner predental concavity, with first and second preapical teeth close to each other (Fig. 3C), while the inner predental concavity is evident in C. wanningeri, as well as the first and second preapical teeth are moderately separated (Fig. 3D).

Corydalus ralphi sp. nov. and C. wanningeri share a basal protrusion on male gonostylus 9 (Fig. 6A, B), as well as the general structure of gonocoxite and gonostylus 10 (Fig. 6C, D) with C. crossi (Contreras-Ramos 2002: figs 24, 25) (also recorded from Bolívar state), so these three species appear to be phylogenetically related. The latter species, however, may be easily separated from the former two by its darkly patterned wings.