Pentaneura herbeti, Dantas & Pinheiro & Hamada, 2020

Dantas, Galileu P. S., Pinheiro, Marcos P. G. & Hamada, Neusa, 2020, An unusual new species of Pentaneura Philippi (Diptera: Chironomidae) from northeastern Brazil, with an emended diagnosis to the genus, Zootaxa 4786 (1), pp. 81-92 : 82-89

publication ID	https://doi.org/ 10.11646/zootaxa.4786.1.6
publication LSID	lsid:zoobank.org:pub:EE141AE8-282F-4035-B332-7F3D6E352EC3
DOI	https://doi.org/10.5281/zenodo.3866582
persistent identifier	https://treatment.plazi.org/id/082687BE-FFE0-C578-73CA-FB7DFA3CA942
treatment provided by	Plazi
scientific name	Pentaneura herbeti
status	sp. nov.

Treatment

Pentaneura herbeti View in CoL sp. nov.

Type material. Holotype: male with pupal exuvia, BRAZIL, Rio Grande do Norte, Parnamirim, Pium river , 05º57’30.5”S / 35º10’02.0”W, 01.ix.2015, G.P.S. Dantas and M. P. G. Pinheiro ( INPA) GoogleMaps . Paratypes: 2 males with pupal exuviae, as holotype; 1 female with pupal exuvia, as holotype ( INPA) ; 1 female gynandromoph (with male genitalia), with pupal and larval exuviae ( INPA) .

Diagnostic characters. Male: spur of front tibia with 8 teeth; gonostylus with a dorsal lamella at the apex.

Pupa: respiratory atrium ( RA) with two diverticula, one apical and one in the mid portion; RA connected to the subbasal portion of the small plastron plate; internal margins of the anal lobe parallel-sided. Larva: S7 multi-branched, S9 bifid; S5 markedly posteromedial to DP; inner teeth of the ligula with tips strongly curved outwardly.

Etymology: the name is in honor of Dr. Herbet Tadeu de Almeida Andrade, for his constant support and in recognition of his initiative in study on aquatic macroinvertebrates in the Rio Grande do Norte State, Brazil.

Adult male (n= 1–3). Total length 1.95–2.21 mm. Total length/ wing length 1.50–1.69. Wing length/ length of profemur 2.10–2.18.

Coloration. Head, thorax and abdomen brown. Antenna brown, palpomeres light brown. Wings with unmarked membrane, covered with macrotrichia. Front leg brown, mid and hind legs with femurs yellow, tibiae and tarsus light brown.

Head ( Fig. 1A View FIGURE 1 ). Antenna: AR 1.30–1.34, flagellum 705–708 µm long, apical flagellomere not offset, evenly tapering from base to apex, conical, 60–64 µm long, 22–25 µm wide, apical seta 48–55 µm long, pedicel with 4 setae on inferior margin. Eyes bare; dorsomedial extension well developed, 85–90 µm long, 66–75 µm wide, medially separated by 55–58 µm; setigerous lobe dorsolaterally between base of pedicel and eyes ( Fig. 1B View FIGURE 1 ). Temporal setae 10–12, uniserial. Postorbital 1. Clypeus 92–105 μm long, 62–65 μm maximum width, with 18–21 setae. Cibarial pump with anterior margin slightly concave, 208–218 μm long, orifice 52–58 from apex. Tentorium 145–156 μm long. Palpomere lengths (I–V in μm): 35–40; 62–72; 128–146; 150–174; 220–250.

Thorax ( Fig. 1C View FIGURE 1 ). Acrostichals 40–46, biserial, diverging posteriorly; dorsocentrals 18–23; prealars 6–7; supraalar 1. Antepronotum with 2 lateral setae, small tubercle present. Scutellum with 14–17 setae, biserial or triserial.

Wing ( Fig. 1D View FIGURE 1 ). Length 1.28–1.31 mm, width 0.38–0.39 mm. Membrane densely covered with macrotrichia; C slightly produced beyond apex of R 4+5. Brachiolum with 3 setae. Squama with 5–8 setae. VR 0.92–0.93. WW 0.30.

Legs. Foretibia 40–42 μm wide at apex, with one lyrate apical spur 23 μm long, bearing 8 teeth. Mid tibia 42–43 μm wide at apex, with two apical somewhat lyrate spurs, 24 and 26 μm long, bearing 3 and 5 lateral teeth, respec- tively. Hind tibia 42 μm wide at apex, with two apical somewhat lyrate spurs, 26 and 27 μm long, bearing 3 and 5 teeth, respectively; tibial comb reduced, with 5 bristles. All legs with slender, curved claws. Lengths and proportions of male legs as in Table 2.

Hypopygium ( Figs. 2 View FIGURE 2 A–C). Tergite IX with 4–7 setae. Anal point broad. Phallapodeme markedly elongate and curved, 92 μm long; sternapodeme with a weak anterior process. Gonocoxite robust, 80–85 μm long, with a dor- somedial setigerous basal area. Inferior volsella absent. Gonostylus slightly curved, 45–46 μm long, with a dorsal lamella at the apex; megaseta robust, 9 μm long. HR 1.78–1.85; HV 4.80.

Female (n= 1). Total length 1.66 mm. Total length/ wing length 1.42. Wing length/ length of profemur 2.04.

Coloration. Head, thorax and abdomen brown. Antenna brown, palpomeres light brown. Wings with unmarked membrane, covered with macrotrichia. Legs with femurs light brown, slightly darker at apex; tibiae and tarsus brown.

Head ( Fig. 3A View FIGURE 3 ). Antenna: AR 0.30, flagellum 962 µm long, apical flagellomere 222 µm long, apical seta 66 µm long, pedicel with a row of 7 setae, scape with 5 ventral setae. Eyes bare; dorsomedial extension well developed, 75 µm long, 75 µm wide, medially separated by 62 µm. Temporal setae 9, uniserial. Postorbital 1. Clypeus 102 μm long, 72 μm maximum width, with 26 setae. Cibarial pump with anterior margin slightly concave, 215 μm long, orifice placed 68 μm from apex. Tentorium 133 μm long. Palpomere lengths (I–V in μm): 37; 70; 133; 171; 287.

Thorax ( Fig. 3B View FIGURE 3 ). Acrostichals about 44, biserial, diverging posteriorly; dorsocentrals about 35, multiserial anteriorly, uniserial and biserial posteriorly; prealars 9; supraalar 1. Antepronotum with 2 lateral setae, tubercle present. Scutellum with 18 setae, triserial.

Wing ( Fig. 3C View FIGURE 3 ). Length 1.17 mm, width 0.43 mm. Membrane covered with macrotrichia; C not produced beyond apex of R 4+5. Brachiolum with 2 setae. Squama with about 10 setae. VR 0.92. WW 0.36.

Legs. Foretibia 45 μm wide at apex, with one lyrate apical spur 21 μm long, bearing 8 teeth ( Fig. 3D View FIGURE 3 ). Mid tibia 45 μm wide at apex, with two apical somewhat lyrate spurs, 23 and 25 μm long, bearing 3 and 5 teeth, respectively. Hind tibia 45 μm wide at apex, with two apical somewhat lyrate spurs, 25 and 27 μm long, bearing 3 and 5 teeth, respectively; tibial comb indistinct, with 5 bristles. All legs with slender, curved claws. Lengths and proportions of leg segments as in Table 3.

Genitalia ( Fig. 3E View FIGURE 3 ). Three spherical seminal capsules, with 60 µm in diameter; spermathecal ducts separate for all their length. Coxosternapodeme curved, 85 µm long. Tergite X 120 µm wide, with about 12 setae on each side. Notum 80 µm long. Cercus 21 µm long.

Pupa (n= 3). Total length 2.83–2.97 mm (abdomen and thorax of male).

Coloration. Cephalothorax and wing sheath light brown, without light spots ( Fig. 4B View FIGURE 4 ); thoracic horn with external membrane and plastron plate light-brown, respiratory atrium dark brown. Abdomen as in Figure 4C View FIGURE 4 , all segments brown, I–VII with lighter longitudinal patches on the sides.

Cephalothorax. Dorsal surface slightly roughened. Frontal apotome somewhat triangular, 160–150 μm wide at base. Wing sheath smooth, 808–820 μm long, 310–318 μm maximum width ( Fig. 4B View FIGURE 4 ). Thoracic horn arched, rounded at apex, external membrane covered with scattered spines ( Fig. 4A View FIGURE 4 ), 196–203 μm long, 56–60 μm maxi- mum width; plastron plate small, oval-shaped, 52–55 μm long. Corona well developed, 122–126 μm long. Respira- tory atrium occupying about 50% of the thoracic horn volume, directly connected to the subbasal portion of plastron plate by a small neck; one apical and one medial diverticulum present. Basal lobe well developed, 46–48 μm long; thoracic comb composed by 10–12 tubercles. Dc 1 42 μm long; Dc 2 21 μm long; Dc 3 not observed (absent?) in any analyzed specimen.

Abdomen ( Fig. 4C View FIGURE 4 ). Tergite I with large field of shagreen, formed by small scattered spines, scar 130–140 μm long; TII–TVIII and anal lobe with large field of shagreen formed by small spines arranged in small transverse lines, less defined in TVIII and anal lobe. Sternite I apparently without shagreen, SII–IV with a large field of shagreen composed by spinules arranged in relatively long transversal lines, SV–VIII with large field of shagreen composed by spinules arranged in short transversal lines. TVII with 4 LS setae, all in the posterior half. T VIII with 5 lateral filaments, distal margin straight ( Fig. 4D View FIGURE 4 ). Anal lobe elongated ( Fig. 4D View FIGURE 4 ), 374–381 μm long, 217–222 μm wide at base, with 2 lateral macrosetae with adhesive sheath; outer margins with about 14–16 small spinules; inner margin membranous, parallel-sided, without spinules. Genital sac wedge-shaped, 137–142 μm long, 178–180 μm wide at base, not reaching insertion of the second macrosetae. GS/AL 0.37–0.38.

Larva (n= 1).

Coloration. Head yellowish, postoccipital margin brown; apex of mandible dark brown; ligula brownish, darker at apex. Abdomen yellowish; procercus mostly pale, inner margin brown, anal setae light-brown. Claws of posterior parapods yellowish.

Head. Head capsule elongate; cephalic index 0.74. Chaetotaxy as in Figures 5 View FIGURE 5 A–B. Dorsally, S5, DP, and S8 nearly aligned diagonally; S8 and S7 somewhat close from each other, aligned laterally; S7 pit large. Ventrally, S10 posterolateral to S9; VP larger than setal pits, closer to S10 than S9; SSm postero-median to S9. SSm, S7 multibranched, S9 bifid, S5 not observed, S8 and S10 simple.

Antenna. Total length 316 μm, A 1 255 μm long, 18 μm maximum width, ring organ placed 155 μm from base, A 2 57 μm long. AR 4.05.

Maxilla ( Fig. 5C View FIGURE 5 ). Maxillary palp arising from a prominent palpiger. Basal palp segment 38 μm long and 10 μm wide, ring organ placed 21 μm from base. A 1 /P 1 6.71; A 2 /P 1 1.50.

Mandible ( Fig. 5D View FIGURE 5 ). Curved and gradually narrowed towards apex, 85 μm long, with 3 lateral setae, ring organ placed 20 μm from base. A 1 /Md 3.00.

Mentum and M appendage. Dorsomental teeth reduced, 3 on each side; labial vesicles rounded, 22 μm long. Pseudoradula well-developed, 85 μm long, uniformly granulated. Submentum with a wide rough area ( Figs. 5E View FIGURE 5 ).

Hypopharyngeal complex ( Fig. 5F View FIGURE 5 ). Ligula 65 μm long, 40, 22 and 20 μm wide at apex, middle and base re- spectively, with five teeth, anterior row of teeth somewhat straight; tip of inner teeth curved outwardly; granulated at base not expanding laterally. Paraligula bifid and slender, 35 μm long, with a basal spur. Pecten hypopharyngis with about 14 teeth on each side.

Body ( Fig. 5G View FIGURE 5 ). Abdomen without fringe of swim-setae; with scattered lateral and ventral setae, some of which are multi-branched. Anterior parapods with simple claws, curved at apex. Posterior parapods with hooklets and simple claws of varied format. Subbasal seta of posterior parapod simple, 225 μm long. Procercus 175 μm long, 27 μm wide at base, with 7 anal setae, 440 μm long; L/W 6.49. Supraanal seta 560 μm long. Anal tubules damaged.