Labrundinia unicolor Silva

Silva, Fabio Laurindo Da, Fonseca-Gessner, Alaide Aparecida & Ekrem, Torbjørn, 2014, A taxonomic revision of genus Labrundinia Fittkau, 1962 (Diptera: Chironomidae: Tanypodinae), Zootaxa 3769 (1), pp. 1-185 : 171-177

Labrundinia unicolor Silva sp. n.

( Figs 83–85 )

Labrundinia sp. 3 Silva et al. 2013: 600 (DNA barcodes).

Material examined. Type material: Holotype male with pupal and larval exuviae, Brazil: São Paulo, São Carlos, Fazzari resevoir, 21.v.2007, F. L. Silva ( MZUSP). 13 Paratypes: 1 male with pupal and larval exuviae same data as holotype except for Ecological Park, 23.v.2008 ( NTNU); 2 males with pupal and larval exuviae same data as holotype except for Canchin reservoir, 2.ii.2009 ( NTNU); 2 males and 1 female with pupal exuviae as previous except for Canchin reservoir, 2.ii.2009 ( NTNU); 1 male with pupal and larval exuviae same data as holotype except for Ribeirão Preto, Monte Alegre Lake, 7.iv.1998, H. F. Mendes ( NTNU); 1 male with pupal and larval exuviae as previous except for Ribeirão Preto, Monte Alegre Lake, 22.v.2000, H. F. Mendes ( NTNU); 1 pupa with larval exuviae and 3 larvae as previous except for 12.vii.1997 ( NTNU); 1 male with pupal and larval exuviae same data as holotype except for Pirassununga, CEPTA, 10.ix.2010 ( NTNU). 1 male with pupal exuviae as previous ( NTNU).

Etymology. Derived from the Latin unicolor , meaning ‘of a single colour’, and refers to the uniform brown abdomen of the new species.

Diagnostic characters. Labrundinia unicolor sp. n. differs from other Labrundinia species by the combination of the following characters. Adult male: tentorium 90–126 Μm long; R2+3 absent; abdomen completely brown; hypopygium brown, sternapodeme with distinct anterior process. Pupa: thoracic horn semi-globose, external margin convoluted, preapical indentation moderately deep. Larva: surface of head capsule smooth, lateroventral and posteroventral spine groups absent; paraligula multi-toothed, with 4 teeth; subbasal seta of posterior parapod serrated; bifid claw with V-shaped lower indentation.

Description. Adult male (n = 11)

Size. Total length 1.9–2.4 (9) mm. Wing length 1.1–1.4 mm. Total length/wing length 1.51–1.96 (9). Wing length/ profemur length 2.05–3.30.

Coloration. Head brown with dark brown occipital margin; pedicel and antenna brown; maxillary palp pale brown. Thorax pale brown with dark scutum; antepronotum brown; supraalar callus brown. Wing membrane transparent without any marking. Legs brown. Abdomen including hypopygium brown ( Fig. 83L ).

Head ( Figs 83A–E ). Temporal setae 11–15, uniserial ( Fig. 83B ). Eye ratio 1.04–1.38 (8). Tentorium ( Fig. 83C ) 90–126 (8) Μm long. Clypeus 78–107 Μm long, 46–70 Μm wide at largest part, bearing 14–22 setae. Cibarial pump 153–204 Μm long ( Fig. 83D ), with anterior margin concave. Lengths of palpomeres 1–5 (in Μm): 29–43 (6); 38–59 (6); 85–117 (6); 111–157 (3); 207–286 (2). Antennal flagellum 740–860 (6) Μm long, diameter of pedicel 116–142 (4) Μm, apical setae single ( Fig. 83E ), AR 1.35–1.54 (6).

Thorax. Antepronotum with 2–4 (7) lateral setae. Acrostichals 42–46 (7), biserial, diverging evenly posteriorly, starting close to antepronotum and almost reaching scutellum; dorsocentrals 24–36 (9), irregularly uniserial; prealars 9–14 (10); supraalars 2–3. Anapleural suture ratio 0.33–0.49 (7). Scutellum with transverse row of 8–10 setae and group of numerous fine anterior setae.

Wing ( Fig. 83F ). Width 0.3–0.4 mm. Costa 0.9–1.2 mm long. R2+3 absent. VR 0.68–0.78. WW 0.29–0.32. Brachiolum with 2 setae. Squama setiferous.

Legs ( Figs 83G–K ). Fore leg: width at apex of tibia 30–39 Μm ( Fig. 83G ), tibia with single, apical and pectinate spur 13–20 Μm long ( Fig. 83H ), with 3–5 lateral teeth and two preapical setae; ta1-4 without any preapical pseudospurs. Mid leg: width at apex of tibia 31–38 Μm long ( Fig. 83I ), tibia with single, apical and pectinate spur 14–26 Μm long with 3–7 teeth ( Fig. 83J ) and two preapical setae; ta1-4 each with two preapical pseudospurs. Hind leg: width at apex of tibia 32–38 Μm long ( Fig. 83K ), tibia without spur; comb 8 setae; ta1-4 without any preapical pseudospurs. Claws slender, hooked; pulvilli absent. Lengths and proportion of leg segments as in Table 57.

fe ti ta1 ta2 ta3

p1 400–518 372–494 318–454 190–259 114–143 p2 501–640 456–505 513–564 192–258 110–148 p3 492–556 441–581 534–569 236–263 133–175

ta4 ta5 LR BV SV

p1 85–101 56–85 0.72–0.82 2.28–2.87 2.16–3.05 p2 94–119 72–88 1.07–1.17 2.34–2.91 1.97–2.17 p3 113–120 72–95 0.97–1.06 2.53–2.83 1.90–2.03 Hypopygium ( Fig. 83M ). Tergite IX arched, with 8–12 posterior setae. Membranous anal point broad, apical edge rounded. Phallapodeme 53–70 Μm long. Sternapodeme with distinct anterior process. Gonocoxite cylindrical, 123–160 (10) Μm long, 65–90 (10) Μm wide, with slightly concave inner margin. GcR 1.75–2.15 (10). Gonostylus simple and slender, 94–123 Μm long; megaseta 15–17 Μm long. HR 1.23–1.52 (10). HV 1.88–2.29 (8).

Adult female (n = 1)

Size. Total length 1.4 mm. Wing length 1.0 mm. Total length/wing length 1.41. Wing length/ profemur length 2.25.

Coloration. Head brown with dark brown occipital margin; pedicel and antenna brown; maxillary palp pale brown. Thorax brown with dark scutum. Wing membrane transparent without any marking. Legs brown. Abdomen completely brown. Seminal capsules brown.

Head. Temporal setae 12, uniserial. Eyes ratio 1.04. Tentorium 137 Μm long. Clypeus 85 Μm long, 64 Μm wide at largest part, bearing 21 setae. Cibarial pump 193 Μm long, as in male. Lengths of palpomeres 1–4 (in Μm): 32; 49; 100; 154; palpomeres 5 broken off. Antennal flagellum not measurable, diameter of pedicel 65 Μm.

Thorax. Antepronotum with 2 setae. Acrostichals 60, irregularly uniserial, starting close to antepronotum;

dorsocentrals 35, irregularly uniserial; prealars 17; supraalars 2. Scutellum with transverse row of 10 setae and group of numerous fine anterior setae.

Wing. Width 0.4 mm. Costa 0.9 mm long. R2+3 absent. VR 0.60. WW 0.39. Brachiolum with 2 setae. Squama setiferous.

Legs. Fore leg: width at apex of tibia 34 Μm, tibia with single, apical and pectinate spur 14 Μm, with three lateral teeth and two preapical setae; preapical pseudospurs on ta1-4 not observed. Mid leg: width at apex of tibia 38 Μm, tibia with single, apical and pectinate spur 21 Μm, with three lateral teeth and two preapical setae; preapical pseudospurs on ta1-4 not observed. Hind leg: width at apex of tibia 46 Μm long, tibia without spur; comb with 8 bristles; preapical pseudospurs on ta1-4 not observed. Claws slender, hooked; pulvilli absent. Lengths and proportion of leg segments as in Table 58.

fe ti ta1 ta2 ta3 p1 452 355 – – – p2 562 450 – – – p3 478 517 – – –

ta4 ta5 LR BV SV p1 – – – – – p2 – – – – – p3 – – – – – Genitalia. Gonapophysis VIII broadly rounded, 61 Μm long. Coxosternapodeme 70 Μm long. Postgenital plate rounded. Cerci oval-quadrate, 51 Μm long and 14 Μm wide; with 9 elongated setae. Labia with inconspicuous microtrichia. Notum length 93 Μm long. Seminal capsules oval, 38 Μm long, 32 Μm wide, with conical shaped necks. Length ratio SCa/No 0.41.

Pupa (n = 13 unless otherwise stated)

Size. Abdomen 1.7–2.3 (12) mm long in male, 2.2 (1) mm long in female.

Coloration. Exuviae mostly pale brown; thoracic horn and apex of anal lobe brown.

Cephalothorax ( Figs 84A–C ). Frontal apotome smooth ( Fig. 84A ). Wing sheath smooth 0.8–1.1 mm long. Thoracic horn 216–350 Μm long and 80–138 Μm wide ( Fig. 84B ), THR 1.93–2.89, preapical indentation moderately deep. Membranous preapical papilla 22–40 (10) Μm long ( Fig. 84C ), PTH 0.06–0.16 (10), aeropyle tube simple, short, 22–33 (9) Μm long; plastron plate small. Horn sac well developed, completely filling respiratory atrium. Reticulation of respiratory atrium indistinct, external membrane with pale spinules. Basal lobe wedgeshaped. Thoracic comb with 7–8 conical tubercles ( Fig. 84B ).

Abdomen ( Figs 84D–E ). Tergite I with scar 104–148 Μm long. T I–V without shagreen, T VI–VIII with shagreen basally concentrated. Abdominal chaetotaxy as in figure 84D. Abdominal segment VII with 4 LS-setae. A VIII with 5 LS-setae. Anal lobe 258–356 Μm long and 138–198 Μm wide ( Fig. 84E ), outer margins sclerotized, with 8–14 spines, longest spine 9–15 Μm long, inner margins of lobes membranous. ALR 1.55–2.30. Male genital sac extending much beyond apex of anal lobe.

4th instar larva (n = 11 unless otherwise stated)

Coloration. Head pale yellow, without maculation; postoccipital margin brown. Second antennal segment brown; distal tooth of mandible and apex of ligula brown. Abdomen pale yellow; procercus and anal setae pale brown. Posterior parapod claws all pale yellow.

Head ( Fig. 85A ). Length 412–640 Μm, 235–316 Μm wide. IC 0.48–0.65. Surface smooth; lateroventral and posteroventral spine groups absent. Ventral cephalic setae S9, S10 and SSm forming a more or less straight line diagonal to longitudinal axis of head capsule ( Fig. 85A ).

Antenna ( Figs 85B–C ). Length 315–358 (8) Μm, A1 217–260 (8) Μm long, with ring organ located 0.86–0.92 (6) from base, A2 79–89 (8) Μm long. AR 2.26–2.66 (6). Blade longer than A2 over-reached by accessory blade.

Maxilla ( Fig. 85D ). Basal palp segment 21–31 Μm long and 7–10 Μm wide at the middle, with ring organ located 0.69–0.87 (8) from base. PR 2.20–4.14. APR 7.82–11.6.

Mandible ( Fig. 85E ). Length 55–72 Μm. Sensillum campaniformium located 0.66–0.76 from apex, basal tooth bifid, with seta subdentalis projecting from sloping end towards apical tooth, accessory tooth present, AMD 3.29– 4.38.

Mentum and M appendage . Dorsomental teeth reduced; pseudoradula uniformly granulate.

Hypopharyngeal complex ( Figs 85F–G ). Ligula 45–60 Μm long, 25–27 Μm wide, with row of 5 teeth. IO 0.95– 1.02, MO 1.00–1.08. Paraligula multi-toothed, with 4 teeth, 19–30 Μm long, inner tooth 15–28 Μm long, shorter than outer tooth. Pecten hypopharyngis with 7–8 teeth almost equal in size.

Body ( Figs 85H–I ). Without lateral fringe. Anterior parapods with simple claws. Procercus 140–204 Μm long, 24–37 Μm wide, with 7 anal setae, 377–561 Μm long. L/ W 4.56 –7.24. Supraanal seta well developed. Anal tubules 235–241 (2) Μm long. Posterior parapod 294–328 (3) Μm long; subbasal seta on posterior parapod serrated, with 4– 6 spines basally ( Fig. 85H ); parapod apex with numerous simple claws; bifid claw with V-shaped lower indentation ( Fig. 85I ). B/C 1.10–1.35 (10).

Remarks. Adult males of Labrundinia unicolor are quite similar to those of L. amandae and differences are discussed under this species. The pupae of L. unicolor also closely resemble those of L. amandae , but may be separated by a convoluted external margin of the thoracic horn. The larvae of L. unicolor appear most similar to those of L. amandae and were fully discussed on the remarks of this species. Labrundinia unicolor and L. amandae can also be separated by their COI gene sequences ( Silva et al. 2013). Labrundinia unicolor has been recorded so far only from São Paulo State, Brazil where it inhabits clear, unpolluted reservoirs.

Figures

FIGURES 83 A – M. Labrundinia unicolor Silva sp. n., adult male. A. Head, frontal view. B. Temporal setae. C. Tentorium. D. Cibarial pump. E. Apex of antenna. F. Wing. G. Apex of fore tibia. H. Fore tibial spur. I. Apex of mid tibia. J. Mid tibial spur. K. Apex of hind tibia with comb. L. Abdominal coloration pattern, dorsal aspect. M. Hypopygium, left: ventral aspect, right: dorsal aspect.

FIGURES 84 A – E. Labrundinia unicolor Silva sp. n., pupa. A. Frontal apotome. B. Thoracic horn with basal lobe and thoracic comb. C. Apex of thoracic horn showing preapical papilla. D. Abdominal segments with chaetotaxy, dorsal aspect. E. Anal lobe and male genital sac, ventral aspect.

FIGURES 85 A – I. Labrundinia unicolor Silva sp. n., larva. A. Head with chaetotaxy, left: ventral aspect, right: dorsal aspect. B. Antenna. C. Apex of antenna. D. Maxillary palp. E. Mandible. F. Ligula and paraligula. G. Pecten hypopharyngis. H. Subbasal seta of posterior parapod. I. Bifid claw of posterior parapod.