Labrundinia parafittkaui 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 : 103-109

Labrundinia parafittkaui Silva sp. n.

( Figs 49–51 )

Labrundinia sp. 15 Silva et al. 2013: 601 (DNA barcodes).

Material examined. Type material: Holotype male with pupal and larval exuviae, Brazil: São Paulo, São Carlos, Monjolinho stream, associated with the aquatic macrophyte, Myriophyllum aquaticum , 20.iv.2011, F. L. Silva ( MZUSP – FA032). 6 Paratypes: 1 male with pupal and larval exuviae same data as holotype ( NTNU). 2 females with pupal and larval exuviae same data as holotype except for 11.iv.2011 ( NTNU). 3 larvae same data as holotype except for 11.iv.2011 ( NTNU).

Etymology. Derived from the Greek para, meaning near, and refers to the similarity of the new species to Labrundinia fittkaui sp. n.

Diagnostic characters. Labrundinia parafittkaui sp. n. differs from other Labrundinia species by the combination of the following characters. Adult male: R2+3 present; abdominal tergite I pale brown, T II–VI with continuous brown transverse band near proximal margin, T VII–VIII completely brown; hypopygium brown, sternapodeme with reduced anterior process; membranous anal point rounded, apical edge convex. Pupa: thoracic horn club-shaped, preapical indentation moderately deep; preapical papilla ratio 0.13–0.19; male genital sac extending much beyond apex of anal lobe. Larva: surface of head capsule covered with small spinules, with small, posteroventral dark brown spot, lateroventral spine group present but weakly developed, with 5–6 spines, posteroventral spine group absent; subbasal seta of posterior parapod simple; bifid claw with V-shaped lower indentation.

Description. Adult male (n = 2 unless otherwise stated)

Size. Total length 1.8–2.1 mm. Wing length 1.1–1.2 mm. Total length/wing length 1.74. Wing length/ profemur length 2.89–3.13.

Coloration. Head brown with dark brown occipital margin; pedicel, antenna and maxillary palp brown. Thorax brown with dark scutum; antepronotum pale brown. Wing membrane transparent without any marking. Legs pale brown. Abdominal tergite I pale brown, T II–VI with continuous brown transverse band near proximal margin, T VII–VIII completely brown; hypopygium brown ( Fig. 49L ).

Head ( Figs 49A–E ). Temporal setae 12, uniserial ( Fig. 49B ). Eye ratio 0.81–0.85. Tentorium ( Fig. 49C ) 139 (1) Μm long. Clypeus 78–85 Μm long, 50–59 Μm wide at largest part, bearing 13 setae. Cibarial pump ( Fig. 49D ) with anterior margin concave, 174–155 Μm long. Lengths of palpomeres 1–5 (in Μm): 24–26; 39–46; 68–98; 90 (1); 153 (1). Antennal flagellum 668 Μm long, diameter of pedicel 102–119 Μm, apical setae single ( Fig. 49E ), AR 1.21 (1).

Thorax. Antepronotum with 4 lateral setae. Acrostichals 34–40, biserial, diverging evenly posteriorly, starting close to antepronotum and almost reaching scutellum; dorsocentrals 20, irregularly biserial; prealars 10–11; supraalars 2. Anapleural suture ratio 0.46. Scutellum with transverse row of 8 setae and group of numerous fine anterior setae.

Wing ( Fig. 49F ). Width 0.3 mm. Costa 0.9–1.0 mm long. R2+3 present. VR 0.68–0.75. WW 0.27–0.28. Brachiolum with 2 setae. Squama setiferous.

Legs ( Figs 49G–K ). Fore leg: width at apex of tibia 29–31 Μm ( Fig. 49G ), tibia with single, apical and pectinate spur 10–11 Μm long ( Fig. 49H ), with three lateral teeth and two preapical setae; ta1-4 without any preapical pseudospurs. Mid leg: width at apex of tibia 29–33 Μm long ( Fig. 49I ), tibia with single, apical and pectinate spur 17–20 Μm long with three lateral teeth ( Fig. 49J ) and two preapical setae; ta1-4 each with two preapical pseudospurs. Hind leg: width at apex of tibia 32 Μm long ( Fig. 49K ), tibia without spur; comb with 6 bristles; ta1-4 without any preapical pseudospurs. Claws slender, hooked; pulvilli absent. Lengths and proportion of leg segments as in Table 33.

fe ti ta1 ta2 ta3

p1 335–418 403–466 281 192 136 p2 446–550 402–475 573 241 123 p3 403–488 523–609 547 238 149

ta4 ta5 LR BV SV p1 101 67 0.60 2.35 3.15 p2 89 76 1.20 3.02 1.79 p3 110 71 0.90 2.90 2.00 Hypopygium ( Fig. 49M ). Tergite IX arched, with 8 posterior setae. Membranous anal point rounded, apical edge convex. Phallapodeme 46–49 Μm long. Sternapodeme with reduced anterior process. Gonocoxite cylindrical, 84–100 Μm long, 38–46 Μm wide, with slightly concave inner margin. GcR 2.16–2.19.

Gonostylus simple and slender, 56–70 Μm long; megaseta 11–12 Μm long. HR 1.45–1.50. HV 3.03–3.33.

Adult female (n = 2 unless otherwise stated)

Size. Total length 1.8–2.0 mm. Wing length 0.8–0.9 mm. Total length/wing length 1.74. Wing length/ profemur length 2.74.

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

Head. Temporal setae 10–12, uniserial. Eyes ratio 0.97 (1). Tentorium 121–124 Μm long. Clypeus 69–75 Μm long, 53–62 Μm wide at largest part, bearing 15–18 setae. Cibarial pump 159–164 Μm long, as in male. Lengths of palpomeres 1–5 (in Μm): 30–39; 54–56; 70–84; 100 (1); 193 (1). Antennal flagellum 331–319 Μm long, diameter of pedicel 52–53 Μm, AR 0.38–0.39.

Thorax. Antepronotum with 4 lateral setae. Acrostichals 36–42, irregularly biserial, starting close to antepronotum; dorsocentrals 20–22, irregularly biserial; prealars 9; supraalars 2. Scutellum with transverse row of 10–11 setae and group of numerous fine anterior setae.

Wing. Width 0.3 mm. Costa 0.7 mm long. R2+3 present. VR 0.64–0.66. WW 0.37–0.38. Brachiolum with 2 setae (2). Squama setiferous.

Legs. Fore leg: width at apex of tibia 30 (1) Μm, tibia with single, apical and pectinate spur 16 Μm long, with three lateral teeth and two preapical setae; preapical pseudospurs on ta1-4 not observed. Mid leg: width at apex of tibia 32–34 Μm, tibia with single, apical and pectinate spur 17–19 Μm long, with three lateral teeth and two preapical setae; preapical pseudospurs on ta1-4 not observed. Hind leg: width at apex of tibia 31–36 Μm, tibia without spur; comb with 6 bristles; preapical pseudospurs on ta1-4 not observed. Claws slender, hooked; pulvilli absent. Lengths and proportion of leg segments as in Table 34.

fe ti ta1 ta2 ta3 p1 318 293 – – – p2 442–444 365–384 – – – p3 395–397 442–468 – – –

ta4 ta5 LR BV SV p1 – – – – – p2 – – – – – p3 – – – – – Genitalia. Gonapophysis VIII broadly rounded, 60–73 Μm long. Coxosternapodeme 50–60 Μm long. Postgenital plate rounded. Cerci oval-quadrate, 43–51 Μm long and 14–15 Μm wide; with 5 elongated setae. Labia with inconspicuous microtrichia. Notum length 78–81 Μm long. Seminal capsules oval, 34–38 Μm long, 34–36 Μm wide, with conical shaped necks. Length ratio SCa/No 0.44–047.

Pupa (n = 4 unless otherwise stated)

Size. Abdomen 1.6–1.8 (2) mm long in male, 1.5–1.6 (2) mm long in female.

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

Cephalothorax ( Figs 50A–C ). Frontal apotome smooth ( Fig. 50A ). Wing sheath smooth 0.6–0.8 mm long. Thoracic horn 184–206 Μm long and 48–59 Μm wide ( Fig. 50B ), THR 3.27–3.63, preapical indentation moderately deep. Membranous preapical papilla 22–39 Μm long ( Fig. 50C ), PTH 0.13–0.19, aeropyle tube simple, short and robust, 14–21 Μm long; plastron plate small. Horn sac well developed, completely filling respiratory atrium. External membrane with pale spinules basally concentrated. Basal lobe wedge-shaped. Thoracic comb with 11 conical tubercles ( Fig. 50B ).

Abdomen ( Figs 50D–E ). Tergite I with scar 104–137 Μm long. T I–VI without shagreen, T VII–VIII with shagreen basally concentrated. Abdominal chaetotaxy as in figure 50D. Abdominal segment VII with 4 LS-setae. A VIII with 5 LS-setae. Anal lobe 193–258 Μm long and 115–134 Μm wide ( Fig. 50E ), outer margins sclerotized, with 5–9 spines, longest spine 8–12 Μm long, inner margins of lobes membranous. ALR 1.67–1.93. Male genital sac extending much beyond apex of anal lobe.

4th instar larva (n = 7 unless otherwise stated)

Coloration. Head pale yellow, with small, posteroventral dark brown spot; 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. 51A ). Length 416–456 Μm, 282–304 Μm wide. IC 0.61–0.69. Surface covered with small spinules; lateroventral spine group present but weakly developed, with 5–6 spines; posteroventral spine group absent. Ventral cephalic setae S9, S10 and SSm forming a more or less straight line perpendicular to longitudinal axis of head capsule ( Fig. 51A ).

Antenna ( Figs 51B–C ). Length 235–248 Μm, A1 156–167 Μm long, with ring organ located 0.84–0.92 from base, A2 66–76 Μm long. AR 1.76–2.15. Blade longer than A2 over-reached by accessory blade.

Maxilla ( Fig. 51D ). Basal palp segment 23–39 (6) Μm long and 7–10 (6) Μm wide at the middle, with ring organ located 0.76–0.83 (6) from base. PR 2.64–3.76 (6). APR 4.45–7.35 (6).

Mandible ( Fig. 51E ). Length 55–68 (6) Μm. Sensillum campaniformium located 0.65–0.81 (6) from apex, basal tooth bifid, with seta subdentalis projecting from sloping end towards apical tooth, accessory tooth present, AMD 2.30–2.93.

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

Hypopharyngeal complex ( Figs 51F–G ). Ligula 49–62 Μm long, 22–24 Μm wide, with row of 5 teeth. IO 0.96– 0.99, MO 1.03–1.09. Paraligula bifid, 23–30 Μm long, inner tooth 17–22 Μm long, shorter than outer tooth. Pecten hypopharyngis with 6 teeth almost equal in size.

Body ( Figs 51H–I ). Without lateral fringe. Anterior parapods with simple claws. Procercus 113–132 (6) Μm long, 26–32 Μm wide, with 7 anal setae 329–372 (2) Μm long. L/ W 3.57 –4.94. Supraanal seta well developed. Anal tubules 377 (1) Μm long. Posterior parapod 259–305 (5) Μm long; subbasal seta on posterior parapod simple, basal spines reduced ( Fig. 51H ); parapod apex with numerous simple claws; bifid claw with V-shaped lower indentation ( Fig. 51I ). B/C 1.10–1.15 (5).

Remarks. Adult males of Labrundinia parafittkaui are very similar to those of L. gregi , but can be separated by the convex apical edge of the anal point, which contrasts the notched apical edge present in L. gregi . The pupae and larvae of L. parafittkaui appear most similar to those of L. pilosella , but can be separated by the shallow preapical indentation, which contrasts the deep preapical indentation, forming a distinct diverticulum in L. pilosella . The larvae of L. parafittkaui may be distinguished from those of the related species L. fittkaui and L. gregi by its characteristic posteroventral dark brown spot on the head capsule. Labrundinia parafittkaui has been recorded only from its type locality in São Paulo State, Brazil. The larvae were collected associated with the aquatic macrophyte, Myriophyllum aquaticum .

Figures

FIGURES 49 A – M. Labrundinia parafittkaui 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 50 A – E. Labrundinia parafittkaui 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 51 A – I. Labrundinia parafittkaui 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.