Pseudochironomus capivara, Trivinho-Strixino & Shimabukuro, 2018

Trivinho-Strixino, Susana & Shimabukuro, Erika Mayumi, 2018, Brazilian Pseudochironomini (Diptera: Chironomidae) Part 2. New Pseudochironomus and Riethia species, Zootaxa 4403 (2), pp. 245-260 : 246-248

Pseudochironomus capivara sp. n.

( Figs 1–2 )

Type material. Holotype: male, slide mounted in Euparal, Brazil, Amazonas, Manacapuru, AM 352, Km 90 (Km 0 8 de Manacapuru )-" Sossego do Vovô ", 03°12’23.0”S, 60°40’21.0”W, 60 m a.s.l., 7–8.ix.2008, light trap, leg. U. G. Neiss; R . L. Ferreira-Keppler; J.F. Barbosa; A. Fernandes , ( Projeto Pronex ) (I1-01, LEIA-UFSCar). Paratypes: 1 male and pupa exuviae, slide mounted in Euparal, Brazil, Roraima, Cantá, Igarapé da Capivara, Ramal do Cantá, 02°44'45.2"N, 60°28'20.8"W, 7.xi.2006, light trap, leg. Fusari, L.M., Azevêdo, C. A. S., Falcão, J . N. (I1-02, LEIA- UFSCar); 1 male, Brazil, Amazonas, Manaus, Reserva Florestal Adolfo Ducke, Igarapé Bolívia , 02° 59'14.5"S 59° 56'30.5"W, 16.ix.2009, leg. G.P.S. Dantas (I1-03, LEIA-UFSCar) ; 1male, Brazil, Amazonas, Novo Airão, Km 3 do ramal do Hotel Mercuri , 02°50'44.4"S, 60°54'56.9"W, 09.ix.2008, em tronco, leg. G.P.S. Dantas (I1-04, LEIA- UFSCar).

Derivatio nominis. The name capivara refers to one of the type localities, Capivara Igarapé. The name is treated as a noun in apposition.

Diagnostic characters. Adult male of Pseudochironomus capivara sp. n. differs from all other species of the genus by the combination of the following characters. Adult male: Thorax with acrosticals. Tergite IX distally protruding and without anal point; hooklike superior volsella, with three simple setae; median volsella short semi triangulate with three large setae; pars ventralis fused or partially divided at the apex; inferior volsella enlarged distally with microtrichia and several marginal large setae. Pupa: Sternite 1 bare; posterolateral comb of tergite VIII, with one large tooth and two shorter teeth

Description. Male (n = 4) Total length 4.69–4.83 mm. Wing length 1.80–2.09 mm.

Coloration. Thorax marked with light brown vitae; abdomen with transversal brown bands on each segment. Legs brown.

Head. Temporal 18–24 setae. Clypeus with 24–31 setae. Antenna with 13 flagellomere, 1.08 – 1.33 mm long; AR 1.91–2.01. Palpomere 2–5 lengths: 63–75, 155–187, 200–219, 275–317 µm.

Thorax ( Fig. 1a ). Ac 6–8; Dc 10–12; Pa 4–5; Scts 18–24.

Wings ( Fig. 1b ). Width 0.54–0.61 mm. VR 1.02–1.08. Brachiolum with two setae. Veins setae on R with 14– 19, R1 with 0–1 and R 4+5 with 6–7 setae. Squama with 17–21 setae.

Legs. Scale on fore tibia, with 55–61 µm long spine at apex. Tibial combs of mid and hind legs partially fused; mid tibial spur anterior, 61–66 µm, posterior 74–77 µm long; hind tibial spur anterior, 63–85 µm, posterior 77–92 µm long. Lengths and proportions of legs as in Table I.

TABLE I. Lengths (in µm) and proportions of legs of Pseudochironomus capivara sp. n. male (3).

Hypopygium ( Fig. 1c, d ). Tergite IX distally protruding and without anal point. Laterosternite with seven setae. Transverse sternapodeme 96 µm long, with developed oral projections. Phallapodeme near 169 µm long. Pars ventralis narrow, 54–69 µm long partially fused. Gonocoxite 100–123 µm long, with pointed apex. Superior volsella hooklike, with three preapical simple setae. Median volsella short semi triangulate with 2–3 simple setae near apex. Inferior volsella pubescent with several marginal large and ventral setae. Gonostylus 123–144 µm long. HR 0.81–0.95.

Pupa ( Fig. 2 ). Cephalotorax. Frontal apotome weakly granulose with short cephalic tubercles; frontal setae absent ( Fig. 2a ). Thorax granulose; two antepronotals, longest setae 281 µm long; three precorneals and four dorsocentrals ( Fig. 2b ). Distance Dc1-Dc2 44 µm; Dc2-Dc3 381 µm; Dc3-Dc4 31 µm.

Abdomen. Length 4.1 mm. Sternite I without spines. Tergite I with fine shagreen in middle part. Tergite II-VI with variable patterns of shagreen and anterior bands of stronger shagreen ( Fig. 2c, d ). Tergite IV with a mediananterior band 250 µm long of fine spines. Tergite VII and VIII with weak shagreenation ( Fig. 2d ). Hooklets row extending nearly on 1/2 the width of tergite II. Pedes spurii B present on segment II. Pedes spurii A present on segment IV. Conjunctives III/IV to IV/V with continuous bands of spinules; IV/V band short. Tergite VIII with posterolateral comb, with one large tooth and two shorter teeth ( Fig. 2e ). Segments I-IV with 0, 3, 3, 3 L setae, respectively; segments V with three taeniae; segments VI-VII with four taeniae; segment VIII with five taeniae. Anal lobe 285 µm long, with anterior weak shagreenation and complete fringe of taeniae. Genital sac 331 µm long.

Figures

FIGURE 1. Pseudochironomus capivara sp. n. male. (a) Thorax. (b) Wing. (c) Hypopygium. (d) Hypopygium, right ventral view, left dorsal view.

FIGURE2. Pseudochironomus capivara sp.n. pupa.(a) Frontal apotome.(b) Anterior part of thorax.(c, d) Abdominal tergite. (e) Posterolateral spurs of segment VIII.