Anacroneuria minuta Klapálek, 1922

Ribeiro, José Moacir Ferreira & Gorayeb, Inocêncio De Sousa, 2014, Description of immatures and association with adults of three species of Anacroneuria Klapálek (Plecoptera: Perlidae) of the Brazilian Amazon, Zootaxa 3881 (1), pp. 17-32 : 23-26

Anacroneuria minuta Klapálek, 1922

( Figs. 12–22 )

Anacroneuria minuta Klapálek 1922: 89 ; Kimmins 1970: 345; RibeiroFerreira & Froehlich 2001:188, Figs.1–4 (redescription); Froehlich 2002: 82, Figs. 18–21 (redescription); Ribeiro & Rafael 2009: 2, Figs. 1–5 , 16–25 (key); Froehlich 2010: 162 (catalogue).

Diagnosis of nymph. Female: Body light yellow. Frons and labrum dark yellow, parietalia mostly whitish, yellowish at epicranial line. Pronotum yellow, whitish laterally. Mesonotum and metanotum yellow with whitish muscle insertions.

Description of nymph. Female: Body length 5.0– 10.4 mm. (not including the cerci, n=4), general color light yellow, body slender ( Fig. 12 ). Head: Antennae light yellow, basally dark yellow. Occiput with U-shaped spot in dorsal view indistinct. Frons light brown, M-line distinct, light spot at surrounding lateral ocelli. Parietalia light yellow, light brown at coronal line and part of postfrontal line. Eyes black; distance between ocelli 0.3 mm, from ocelli to inner margin of eye, 0.4 mm ( Figs. 13, 14 ). Mouthparts light yellow. Labrum dark yellow, a small anteromedian area whitish with fine setae. Maxillae light yellow, sclerotized outer part of cardo and stipes yellowish, medial limit of stipital sclerotization brownish; lacinia with two dark brown teeth and, basally a row of four robust bristles ( Fig. 15 ). Mandible: light yellow, five pointed teeth on distal margin, decreasing in size towards base, but with the 3th and 5th smaller and 2th and 4th of same size ( Figs. 16, 17 ). Thorax: Pronotum wider than long (with 1.1 mm long and 2.7 mm wide), light yellow without medial spots, lateral margins pale, posterior border concave, median pronotal sulcus and narrow lateral strip paler. Prosternum margin pale yellow with sulci wellmarked, angle of the anterior arms of Y-line long, without small groups of setae anterolateral to Y-stem ( Figs. 13 , 19 ). Mesonotum and metanotum dark yellow, mesonotum 1.3 mm long by 2.3 mm wide, median light area, without lateral brown bands, mesonotum covered with fine, dark pilosity contrasting with yellowish background; lateral border the wing pad whitish; metanotum with 1.2 mm long and 2.0 mm wide, similar to mesonotum, with spots varying in size and shape ( Fig. 18 ). Gills with filaments with the following configuration: ASC1, PSC1 with two branchiae, AT2, AT3, PT3, A1 with double branchiae; ASC, PSC (2, 3) and SL absent ( Fig. 19 ). Leg dorsally light yellow, lighter ventrally, trochanter with bristles thin and long distally, and base of tibia dark yellow, coxa with few bristles; femur with transverse rows of strong bristles on the dorsal upper margin, but absent in the posterior ventral area; dorsally tibiae with rows of short and thick bristles on the anterior margin, with a fringe of whitish, fine and dense bristles on the entire segment, posteroventral margin with three strong large spines; tarsus whitish yellow, without strong bristles; ventrally pale with fine bristles ( Figs. 20, 21 ). Abdomen dorsally light to dark yellow, following the general pattern of body, becoming gradually lighter in the last four segments, membranous areas dark brown, visible between the segments, margins anterior and posterior of each segment darker, posterior margin dorsally of terga with a complete row of bristles which are longer and more visible, gradually from of the second segment; these rows of bristles extend ventrally and laterally of the sterna to one-quarter of the width of each sternite of segments 4 to 7; the rows of bristles are complete on sternites 8 to 10, the eighth sternite presents a median V-shaped notch with margin clearly sclerotized; the integument of the abdominal segments covered with very fine and sparse bristles, the two last sternites with long bristles on the distal region ( Fig. 22 ). Cerci dark to light yellow.

Male: Unknown.

Variation. Not observed.

Distribution. BRAZIL: Amazonas: Manaus, Reserva Florestal Adolpho Ducke and Reserva de Desenvolvimento Sustentável do Tupé; Pará: Castanhal, Apeú River basin).

Remarks. Association with the adult was made by rearing nymphs in tanks in the laboratory at INPA. This species is easily separated from other known nymphal descriptions of the genus by the distinctive light yellow body coloration. It differs of A. marlieri and A. manauensis by the light yellow coloration of the body, head with indistinct M-line, mandible, maxilla, and lacinia, light to dark yellow, shape of base of lacinia rounded, form of external contour of posterior border of pronotum thickened, side of the Y-line without groups of bristles, and light yellow coloration of the femur.

This species is recorded for the states of Amazon and Pará. Four additional adult specimens were identified from material collected in Roraima in the Serra do Tepequém and deposited in the Museu Integrado de Roraima (MIRR), now part of the Instituto de Amparo Ciência, Tecnologia e Inovação de Roraima (IACT). Two nymphs were collected in northeastern Pará with morphological characters similar to this species, but these were immature and were not associated with adults.

Material examined. BRASIL, Amazonas State, Manaus Municipality, CEPLAC (Comissão Executiva do Plano da Lavoura Cacaueira), Rodovia AM-010, Km 30, light trap, 25.viii.1977, I.S. Gorayeb (2 adults female, MPEG); same location, 18.viii.1977, I.S. Gorayeb (1 adult female, MPEG); same location, light trap, 1318. x.1977, I.S. Gorayeb (4 adults female, MPEG); same location, 18.viii.1987, I.S. Gorayeb (1 adult female, MPEG); same location, Reserva Florestal Adolpho Ducke, igarapé Tinga (stream), trap Malaise, 08–11.xi.2010, J.M.F. Ribeiro (1 adult female, MPEG); same location, 1017. iii.2003, F. M. Silva (1 adult female, MPEG); same location, igarapé Uberê (stream), trap Malaise, 1727. xii.2002, J. M. F. Ribeiro & J. Vidal (1 adult male, MPEG); same location, igarapé Bons Amigos (stream), rearing in tank, 18.vi.1987, R.S. Rocha (1 exuvium, 1 adult ♀, INPA); same location, igarapé Barro branco (stream), 14.vi.1989, L. C. Machado & R.S. Rocha (1 nymph, INPA); same location, Reserva de Desenvolvimento Sustentável do Tupé, Igarapé Cachoeira (stream), (0302'03.2''S e 6016'34.6''W), 13.iv.2002, leaf litter, Ponto2, (3 nymphs ♀, INPA); same location, Presidente Figueiredo, igarapé da Onça (stream), ( RPPN Cachoeira da Onça), BR 174 km 108, backwaters and river rapids, 11.ix.2012, F.B.P Gouveia & D.Z. Lopez (1 nymph, MPEG). Pará State, Peixe-Boi Municipality, 07.vii.1982, I.S. Gorayeb (1 adult female, MPEG); Marabá, Municipality, Serra Norte, light trap, 22.ii.1984, O. Silveira (1 male adult, MPEG); same location, 10.viii.1984, P. Tadeu (1 adult male, MPEG); Ourém Municipality, Patauateua, light trap, 20.viii.1992, B.M. Mascarenhas (1 adult female, MPEG); same location, light trap, 21.viii.1992, B.M. Mascarenhas (2 adults male, female, MPEG); same location, Suspended trap, 1517. viii.1992, B.M. Mascarenhas (1 adult female, MPEG).

Ecological notes. This apparently uncommon species was collected from high quality, shallow, rapidly flowing streams such as Barro Branco Stream ( Table 2).

Parameter Value Water temperature (o C) 26.0 pH 4.5 Specific conductance (uS/cm) 13.5 Dissolved oxygen (mg/l) 4.6 Width (m) 3.0 Depth (cm) 0.8 Velocity (m/s) 0.6 Discharge (m3/s) 1.4

Figures

FIGURES 12 – 17. Female Anacroneuria minuta. 12 — body; 13 — head and pronotum, dorsal view; 14 — head, ventral view; 15 — maxillae and lacinia; 16 – 17 — mandible, dorsal and ventral view. (photos: J. M. F. Ribeiro).

FIGURES 18 – 22. Female Anacroneuria minuta. 18 — wing pad; 19 — sulci sternal and gills; 20 – 21 — legs, dorsal and ventral view; 22 — Abdomen, ventral view (photos: J. M. F. Ribeiro).

FIGURES 1 – 6. Female Anacroneuria marlieri. 1 — body; 2 — head and pronotum, dorsal view; 3 — head, ventral view; 4 — maxillae and lacinia; 5 — mandible, dorsal view; 6 — mandible, ventral view (photos: J. M. F. Ribeiro).

FIGURES 23 – 28. ♀ Anacroneuria manauensis. 23 — body; 24 — head and pronotum, dorsal view; 25 — head, ventral view; 26 — maxillae and lacinia; 27 – 28 — mandible, dorsal and ventral view (photos: J. M. F. Ribeiro).