Anacroneuria saofrancisco, Novaes & Vilela & Lopez & Ferreira, 2018

Novaes, Marcos Carneiro, Vilela, Diogo Silva, Lopez, Vinicius Marques & Ferreira, Rhainer Guillermo Nascimento, 2018, Certain species of Plecoptera from the headwater springs of National Integration River (São Francisco), Brazil, Zootaxa 4429 (1), pp. 195-200 : 196-197

Anacroneuria saofrancisco n. sp.

Figures 2–6 .

Material examined. Holotype male: BRAZIL (BR), Minas Gerais State (MG), Serra da Canastra National Park ( SCNP), Rio do Peixe (-20.2569, -46.4097), 17–19.x.2017, GFT, MZSP . Paratypes: BR, MG, SCNP, 2 males and 3 females, Rio do Peixe (20.2569, -46.4097), 17–19.x.2017, GFT, MZSP . Additional material: BR, MG, SCNP, 2 nymphs, Rio do Peixe (-20.2569, -46.4097), 17–19.x.2017, GFT, MZSP .

Description. General color brown. Head light brown with central part yellowish; clypeal area setose; M-line incomplete, slightly visible and with diffuse limits; ( Fig. 2 ); lappets brown; gena and parietalia light brown; postfrontal line U-shaped; antenna and palps brow. Pronotum dark brown, with whitish bands medially and laterally ( Fig. 2 ). Legs, femora light brown, tibia and tarsi darker. Wing membrane and veins brown. Cerci brown.

Male. Forewing length 11.1–11.7 mm. Hammer a truncate cone ( Fig. 3 ). Penial armature with a pair of small ventral, membranous lobes ( Figs. 4–6 ); in dorsal view, 3-lobed apically with lateral lobes (shoulders) well sclerotized ( Fig. 4 ); ventral apical part ( Fig. 5 ) a thin flap-shaped sclerotized structure (ventral membranous lobes are attached to this structure); hooks relatively large, regularly curved and with apex pointed ( Fig. 5 ); dorsal keel absent.

Female. Forewing length 14.7–15.5 mm. Subgenital plate light brown and 4-lobed ( Fig. 7 ). Median notch relatively deep, mesal lobes wider than lateral ones. Lateral lobes slightly shorter than medial ones. Egg elongate oval, ca. 0.22 x 0.45 mm ( Fig. 8 ).

Nymph. General color dark brown. Head dark brown with lighter areas near ocelli, compound eyes and parietallia ( Fig. 9 ); M-line slightly visible and with diffuse limits; eyes and ocelli black. Pronotum dark brown with median line and scattered areas light brown ( Fig. 9 ). Mandibles, maxillae, and labium as in Figs. 10–12 , respectively. Forefemur with lateral surface covered by sparse bristles ( Fig. 13 ); dorsally and ventrally with higher density of thick bristles; dorsally, with strong fringe of hairs. Tibia ventrally with sparse thick bristles, and dorsally with a row of thick bristles and a well-developed band of hairs. Cerci dark brown with thick bristles; segments differ in shape and size from base to apex ( Fig. 14 ). Thoracic gills: ASC1, PSC1, AT2, AT3 and PT3 (sensu Shepard & Stewart 1983; Stewart & Stark 2002). Measurements (n=5): head width 2.9–3.1 mm; head length 1.7– 1.9 mm; antennae length 5.5–5.8 mm; pronotum width 3.0– 3.4 mm; pronotum length 1.8–2.5 mm; cercal length 6.9–7.1 mm; total length (without cerci) 10.9–11.5 mm.

Remarks. The penial armature of A. saofrancisco resembles A. tabatae Froehlich 2010a . However, the apical penial structure of A. saofrancisco is wider than A. tabatae , as shown in ventral, dorsal, and lateral views ( Figs. 4– 6 ). Additionally, A. tabatae has only a single ventral membranous lobe, whereas A. saofrancisco has two.

The head and pronotal color pattern of the nymphs of A. saofrancisco resembles that of A. flintorum Froehlich 2002 ( Almeida et al., 2018). However, the nymph of A. saofrancisco is lighter than A. flintorum . Furthermore, the M-line in A. flintorum is well defined but indistinct in A. saofrancisco .

Etymology. This name refers to the São Francisco River where the specimens were collected.

Figures

FIGURES 2–8. Anacroneuria saofrancisco n. sp. Male holotype: 2. Head and pronotum (Scale bar: 0.5 mm); 3. Subgenital plate with hammer (Scale bar: 1.0 mm); Penial armature, 4. Dorsal view, 5. Ventral view, 6. Lateral view (Scale bar: 1.0 mm). Female: 7. Terminalia (Scale bar: 1.5 mm); 8. Egg: (Scale bar: 0.5 mm).

FIGURES 9–14. Anacroneuria saofrancisco n. sp., nymph: (9) head and pronotum (Scale bar: 1.0 mm); (10) right mandible (Scale bar: 0.1 mm); (11) right maxilla (Scale bar: 0.1 mm); (12) labium (Scale bar: 0.1 mm); (13) prothoracic left leg (Scale bar: 0.5 mm); (14) cerci (proximal view, medial view and distal view) (Scale bar: 0.5 mm).