Paratanytarsus silentii Trivinho-Strixino, 2010

Trivinho-Strixino, Susana & Shimabukuro, Erika Mayumi, 2017, Tanytarsini (Diptera: Chironomidae) from madicolous habitat in Southeast Brazil: new species and new records, Zootaxa 4269 (3), pp. 427-437 : 434-435

Paratanytarsus silentii Trivinho-Strixino, 2010

The male of P. silentii was previously collected by F. Roque in 2000 in a little stream called Córrego do Silêncio located at Parque Estadual do Jaraguá, in São Paulo city. Until this date the immature stages were unknown. Here we describe the pupal exuviae and IV instar larvae, and report new occurrences for the species.

Material examinated. Three 4th instar larvae, Brazil, São Paulo State, Ubatuba , Concorvado Peak , 23˚27'876''S/45˚11'911''W 206 m a.s.l., lateral of a small waterfall, leg E.M. Shimabukuro, G. Perbiche-Neves. 27.x.2013 (A3-31, A3-32, A3-33, LEIA-UFSCar). 2 pupal exuviae in the same slide preparation (A3-30, LEIA- UFSCar) and 2 male of the same locality (A3-34, A3-35, LEIA-UFSCar).

Other records. 1 male, Brazil, São Paulo State, Ubatuba, Concorvado Peak , 23˚26'823''S/45˚11'585’’W 1082 m a.s.l., small current of water in a narrow rocky channel, leg E.M. Shimabukuro, G. Perbiche-Neves. 27.x.2013 . 1 male, Brazil, Rio de janeiro State, Teresópolis, Sino Mountain , 22°26'848'S/43°00'798''W 1444 m a.s.l. marginal rock of a stream, leg E.M. Shimabukuro, G. Perbiche-Neves. 29.vii.2014 .

Description. Pupa (n = 2). Length of abdomen 2.27 (1) mm.

Cephalothorax. Frontal setae elongate, slender, 57 µm long; cephalic tubercles absent.

Frontal apotome smooth ( Fig. 5 b). Thoracic horn elongate, c. 295 µm long, with fringe of setae ( Fig. 5 a). Thorax with weak granulation close to anterior median suture; scutal tubercle absent ( Fig. 5 a). Wing sheath with short nose; pearl row absent. Chaetotaxy of thorax: 3 precorneals (Pc 1-3) and 1 lateral antepronotal (Lap. 3) present on each side. Dc 1–4 situated in two groups, widely separated.

Abdomen. Tergite I without shagreen; II with shagreen in all extension, hardly anteriorly; III with median longitudinal patches of shagreen, hardly anteriorly; IV and V with lateral paired patches of long spines, and 2 circular field of short spines anteriorly in addition to 3–4 long spines ( Fig. 5 c); VI to VIII without shagreen. Hook row continuous, occupying 1/2 width of segment II. Pedes spurii B short. Segment VIII with posterolateral combs consisting of 2–3 marginal brown teeth. Segments I–IV with 0, 3, 3, 1 L setae, respectively; segments IV–VIII with 1, 3, 4, 4 and 5 taeniae seta. Anal lobe with about 28–30 taeniate fringe setae and 1 distal large dorsal taeniae on each side.

4th instar larva (n =3). Small, total length 4.53 mm [3.92–4.58].

Head. Length 317 µm, width 232 µm (1). Clypeal seta (S3) simple.

Antenna ( Fig. 5 e). With 5 segments placed on prominent pedestal, 41 µm long (1); basal segment 115 µm [108–121], longer than flagellum and slightly bent outside; basal ring organ near base; seta 24 µm long in distal ½ part; segment 2 (32 µm) slightly longer than segments 3–5 (12, 8, 5 µm); Lauterborn organs short, pedicels near 22 µm long, slightly shorter than segments 3–5. Pecten epipharyngis consisting of 3 distally serrated scales ( Fig. 5 d). Premandible with 2 teeth ( Fig. 5 f); brush well developed.

Mandible ( Fig 5 g) 86 µm long with dorsal, apical and two inner teeth brown.

Mentum ( Fig. 5 h) 68 µm long [58–77] with median tooth slightly notched laterally and 5 pairs of lateral teeth all brownish. Ventromental plates slightly longer than mentum close together medially.

Abdomen. Anal tubules slightly shorter (near 100 µm long) than parapods. Claws of posterior parapods simple. Eleventh abdominal with a posterior dorsal hump ( Fig. 5 i).

Remarks. The main characteristics that differentiate the P. silentii pupal exuviae from P corbii Trivinho- Strixino, 2010 is the absence of cephalic tubercles and the posterior pair of long spines bands on tergite III in the former. The larvae differentiate by the short pedicels of Lauterborn organs and the unusual presence of a dorsal hump on eleventh abdominal segment.

New Tanytarsus records: Tanytarsus giovanni Sanseverino & Trivinho-Strixino, 2010 male, Brazil, Minas Gerais State, Passa-Quatro, Pedra da Mina Mountain , 22˚25'410''S/44˚50'380''W 2575 m a.s.l., madicolous habitat, rock marginal to a stream, leg E.M. Shimabukuro, G. Perbiche-Neves, V. Saito . 14.x.2014 (A3-46, LEIA-UFSCar). Tanyarsus digitatus Sanseverino, 2006 1 male, Brazil, Rio de Janeiro State, Teresópolis, Sino Mountain , 22°26'848''S/43°00'798''W, 1444 m a.s.l. marginal rock of a stream, leg E.M. Shimabukuro, G. Perbiche-Neves.

29.vii.2014 (A3-47, LEIA-UFSCar); 1 male, Brazil, São Paulo State, Ubatuba, Concorvado Peak , 23˚28'20.72''S/ 45˚11'38.43''W 25 m a.s.l., lateral of a small waterfall, leg E.M. Shimabukuro, G. Perbiche-Neves. 27.x.2013 (A3- 48, LEIA-UFSCar).

Figures

FIGURE 5. Paratanytarsus silentii. a – c; Pupa; d – i. Larva. a. Thorax lateral view. b. Frontal apotome. c. Abdominal segments II – V. d. Pecten epipharyngis. e. Antenna. f. Premandible. g. Mandible. h. Mentum. i. Abdomen posterior.