Labrundinia jasoni 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 : 54-59

Labrundinia jasoni Silva sp. n.

( Figs 24–26 )

Labrundinia sp. 23 Silva et al. 2013: 602 (DNA barcodes).

Material examined. Type material: Holotype male with pupal and larval exuviae, Brazil: São Paulo, Luiz Antonio, Beija-Flor reservoir, 19.v.2011, S. Wiedenbrug ( MZUSP – FA109). 2 Paratypes: 1 pupa with larval exuviae same data as holotype except for Óleo lake, 7.i.2011 ( NTNU); 1 pupa and 1 larva same data as holotype except for Óleo lake, 7.i.2011, S. T. Strixino ( NTNU).

Etymology. Named in honour of Jason Weintraub, entomologist of the Academy of Natural Sciences of Philadelphia, for his friendship and encouragement.

Diagnostic characters. Labrundinia jasoni sp. n. differs from other Labrundinia species by the combination of the following characters. Adult male: wing length 1.16 mm; R2+3 absent; abdominal tergites I–II pale, T II–VII with continuous brown transverse band near proximal margin, T VIII completely brown; hypopygium pale, sternapodeme with moderate anterior process. Pupa: thoracic horn shaped like the number ‘9’; shagreen on sternite II with prominent spines; abdominal segment VII with 3 LS-setae; male genital sac extending much beyond apex of the anal lobe. Larva: head capsule surface smooth, lateroventral spine group present, but weakly developed, with 3 spines, posteroventral spine group absent; ligula slender, 54–61 Μm long; subbasal seta of posterior parapod simple; bifid claw with V-shaped lower indentation.

Description. Adult male (n = 1)

Size. Total length 2.4 mm. Wing length 1.2 mm. Total length/wing length 2.09. Wing length/ profemur length 3.06.

Coloration. Head pale brown with dark brown occipital margin; pedicel and antenna brown; maxillary palp brown. Thorax brown with scutum dorsally pale brown; antepronotum pale brown; supraalar callus brown. Wing membrane transparent without any marking. Legs brown. Femur I–III pale brown. Abdominal tergites I–II pale, T II–VII with continuous brown transverse band near proximal margin, T VIII completely brown; hypopygium pale ( Fig. 24L ).

Head ( Figs 24A–E ). Temporal setae 10, uniserial ( Fig. 24B ). Eye ratio 1.13. Tentorium ( Fig. 24C ) 85 Μm long. Clypeus 69 Μm long, 63 Μm wide at largest part, bearing 10 setae. Cibarial pump 188 Μm long ( Fig. 24D ), with anterior margin concave. Lengths of palpomeres 1–4 (in Μm): 31; 46; 98; 110; palpomeres 5 broken off. Antennal flagellum 739 Μm long, diameter of pedicel 138 Μm, apical setae single ( Fig. 24E ), AR 1.30.

Thorax. Antepronotum with 3 lateral setae. Acrostichals 44, biserial, diverging evenly posteriorly, starting close to antepronotum and almost reaching scutellum; dorsocentrals 20, irregularly biserial; prealars 10; supraalars 2. Anapleural suture ratio 0.48. Scutellum with transverse row of 7 setae and group of numerous fine anterior setae.

Wing ( Fig. 24F ). Width 0.3 mm. Costa 1.0 mm long, not produced beyond R4+5. R2+3 absent. VR 0.81 (1). WW 0.28. Brachiolum with 2 setae. Squama setiferous.

Legs ( Figs 24G–K ). Fore leg: width at apex of tibia 39 Μm ( Fig. 24G ), tibia with single, apical and pectinate spur 14 Μm long ( Fig. 24H ), with three lateral teeth and two preapical setae; Ta1-4 without any preapical pseudospurs. Mid leg: width at apex of tibia 34 Μm long ( Fig. 24I ), tibia with single, apical and pectinate spur 24 Μm long with three lateral teeth ( Fig. 24J ) and two preapical setae; ta1-4 each with two preapical pseudospurs. Hind leg: width at apex of tibia 39 Μm long ( Fig. 24K ), tibia without spur; comb with 7 bristles; ta1-4 without any preapical pseudospurs. Claws slender, hooked; pulvilli absent. Lengths and proportion of leg segments as in Table 16.

fe ti ta1 ta2 ta3

p1 378 412 206 219 80

p2 502 374 513 243 110 p3 442 556 546 260 164

ta4 ta5 LR BV SV p1 69 54 0.50 2.37 3.85 p2 93 77 1.37 2.65 1.71 p3 106 73 0.98 2.56 1.83 Hypopygium ( Fig. 24M ). Tergite IX arched, with 13 posterior setae. Membranous anal point rounded, apical edge convex. Phallapodeme 48 Μm long. Sternapodeme with moderate anterior process. Gonocoxite cylindrical, 103 Μm long, 40 Μm wide, with slightly concave inner margin. GcR 2.60. Gonostylus simple and slender, 71 Μm long; megaseta 12 Μm long. HR 1.45. HV 3.40.

Pupa (n = 3 unless otherwise stated)

Size. Abdomen 2.1–2.5 mm long in male, 2.3 mm long in female.

Coloration. Exuviae mostly pale brown. Thoracic horn brown.

Cephalothorax ( Figs 25A–C ). Frontal apotome smooth ( Fig.25A ). Wing sheath smooth 0.8 mm long. Thoracic horn 253–281 Μm long and 119–144 Μm wide ( Fig. 25B ), THR 1.96–2.12, preapical indentation deep. Membranous preapical papilla 38–46 Μm long ( Fig. 25C ), PTH 0.15–018, aeropyle tube simple, elongated and slender, 46–47 (2) Μm long; plastron plate small. Horn sac moderately developed. Reticulation of respiratory atrium indistinct, external membrane with pale spinules. Basal lobe wedge-shaped. Thoracic comb with 9–11 conical tubercles ( Fig. 25B ).

Abdomen ( Figs 25D–F ). Tergite I with scar 110–149 (2) Μm long. T I–VI without shagreen, T VII–VIII with shagreen basal concentrated. Sternite II with prominent spines ( Fig. 25D ). Abdominal chaetotaxy as in figure 25E. Abdominal segment VII with 3 LS-setae. A VIII with 5 LS-setae. Anal lobe 339–375 Μm long and 152–157 Μm wide ( Fig. 25F ), outer margins sclerotized, with 7–8 spines, longest spine 18–24 Μm long, inner margins of lobes membranous. ALR 2.16–2.23. Male genital sac extending much beyond apex of anal lobe.

4th instar larva (n = 3 unless otherwise stated)

Coloration. Head pale yellow, without maculation; postoccipital margin brown. Second antennal segment pale 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. 26A ). Length 519–607 Μm, 313–372 Μm wide. IC 0.60–0.61. Surface smooth; lateroventral spine group present, but weakly developed, with 3 spines; posteroventral spine group absent. Ventral cephalic setae S9, S10 and SSm forming a straight line diagonal to longitudinal axis of head capsule ( Fig. 26A ).

Antenna ( Figs 26B–C ). Length 307–344 Μm, A1 216–249 Μm long, with ring organ placed 0.81–0.90 (2) from base, A2 81–84 Μm long. AR 2.36–2.64. Blade longer than A2 over-reached by accessory blade.

Maxilla ( Fig. 26D ). Basal palp segment 32–33 Μm long and 0.67–0.78 wide at the middle, with ring organ 21– 26 Μm from base. PR 4.57–4.64. APR 6.76–7.63.

Mandible ( Fig. 26E ). Length 53–57 (2) Μm. Sensillum campaniformium 0.58–0.70 (2) from apex, basal tooth bifid, with seta subdentalis projecting from sloping end towards apical tooth, accessory tooth present, AMD 4.11– 4.17.

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

Hypopharyngeal complex ( Figs 26F–G ). Ligula 54–61 Μm long, 28–32 Μm wide, with row of 5 teeth. IO 0.93– 0.99, MO 1.01–1.05. Paraligula bifid, 26–29 Μm long, inner tooth 20–24 Μm long, shorter than outer tooth. Pecten hypopharyngis with 7 teeth almost equal in size.

Body ( Figs 26H–I ). Without lateral fringe. Anterior parapods with simple claws. Procercus 237–244 (2) Μm long, 27–41 (2) Μm wide, with 7 anal setae 537–584 (2) Μm long. L/ W 5.73 –8.91 (2). Supraanal seta well developed. Anal tubules 277 (1) Μm long. Posterior parapod 351–430 Μm long; subbasal seta on posterior parapod simple, without spines ( Fig. 26H ); parapod apex with numerous simple claws; bifid claw with V-shaped lower indentation ( Fig. 26I ). B/C 1.26–1.30.

Adult female. Unknown.

Remarks. Labrundinia jasoni is very similar to L. paulae in the adult males, but can be separated from the former by the shorter wing and the moderately developed anterior process of the sternapodeme. The pupal exuviae are perhaps most similar to those of L. mayaca and L. paravirescens , but can be separated from these species by having 3 LS-setae on the abdominal segment VII. The larvae apparently are most similar to those of L. paravirescens , but L. jasoni can be separated by the shorter ligula. Labrundinia jasoni , L. mayaca , L. paravirescens and L. paulae can also be separated by their partial COI gene sequences ( Silva et al. 2013). Labrundinia jasoni has so far been recorded only from its type locality. The larvae were collected in ox-bow lakes of the Mogi-Guaçu River (Infernão Lake), situated at Jataí Ecological Station (Luiz Antônio, São Paulo State).

Figures

FIGURES 24 A – M. Labrundinia jasoni 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 25 A – F. Labrundinia jasoni 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. Spines on sternite II. E. Abdominal segments with chaetotaxy, dorsal aspect. F. Anal lobe and male genital sac, ventral aspect.

FIGURES 26 A – I. Labrundinia jasoni Silva sp. n., larva. A. Head with chaetotaxy and detail of lateroventral spine group, 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.