Labrundinia reniformis 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 : 133-135

Labrundinia reniformis Silva sp. n.

( Figs 64–66 )

Labrundinia sp. 6 Silva et al. 2013: 600 (DNA barcodes).

Material examined. Type material: Holotype male with pupal and larval exuviae, Brazil: São Paulo, Gália, Caetetus Ecological Station, 1st dam before the Barreiro reservoir, 08.vii.2008, F. L. Silva & J. F. Nunes ( MZUSP). 5 Paratypes: 3 males with pupal and larval exuviae same data as holotype except for, Canchin reservoir, 6.i.2009 ( NTNU). 1 male with pupal and larval exuviae same data as holotype except for, 2.ii.2009 ( NTNU). 1 female with pupal exuviae same data as holotype except for, 2.ii.2009 ( NTNU).

Etymology. Derived from the Latin reniformis , meaning kidney-like, and refers to the shape of pupal thoracic horn.

Diagnostic characters. Labrundinia reniformis sp. n. differs from other Labrundinia species by the combination of the following characters. Adult male: abdominal tergites II–VI with continuous brown transverse band near proximal margin, T VII–VIII almost completely brown; hypopygium pale brown, sternapodeme with much reduced anterior process, hypopygium ratio 1.61–1.77. Pupa: thoracic horn kidney-shaped, preapical indentation reduced, thoracic horn about 1.75–2.08 times as long as wide. Larva: Surface of head capsule covered with small spinules; lateroventral and posteroventral spine groups absent; subbasal seta of posterior parapod simple; serrated claw present; bifid claw with V-shaped lower indentation.

Description. Adult male (n = 5)

Size. Total length 1.9–2.3 mm. Wing length 1.2–1.3 mm. Total length/wing length 1.53–1.71. Wing length/ profemur length 2.94–2.97 (4).

Coloration. Head pale brown with dark brown occipital margin; pedicel and antenna brown; maxillary palp brown. Thorax brown with dark scutum; antepronotum pale brown. Wing membrane transparent without any marking. Legs pale brown. Abdominal tergites II–VI with continuous brown transverse band near proximal margin, T VII–VIII almost completely brown; hypopygium pale brown ( Fig. 64L ).

Head ( Figs 64A–E ). Temporal setae 11–12 (4), uniserial ( Fig. 64B ). Eye ratio 0.89–0.90 (2). Tentorium ( Fig. 64C ) 150–158 (3) Μm long. Clypeus 71–100 (4) Μm long, 57–59 (4) Μm wide at largest part, bearing 11–16 (4) setae. Cibarial pump 177–204 (4) Μm long ( Fig. 64D ), with anterior margin concave. Lengths of palpomeres 1–5 (in Μm): 34–43 (4); 50–65 (4); 114–137 (3); 130–146 (4); 170 (1). Antennal flagellum 676–820 Μm long, diameter of pedicel 103–124 Μm, apical setae single ( Fig. 64E ), AR 1.09–1.27.

Thorax. Antepronotum with 1–2 lateral setae. Acrostichals 30–38, biserial, diverging evenly posteriorly, starting close to antepronotum and almost reaching scutellum; dorsocentrals 16–22, irregularly uniserial; prealars 7; supraalars 2. Anapleural suture ratio 0.47–0.61. Scutellum with transverse row of 6–8 setae and group of numerous fine anterior setae.

Wing ( Fig. 64F ). Width 0.3–0.4 (4) mm. Costa 1.0–1.2 (4) mm long. R2+3 absent. VR 0.72–0.81 (3). WW 0.27– 0.28 (4). Brachiolum with 2 setae. Squama setiferous.

Legs ( Figs 64G–K ). Fore leg: width at apex of tibia 32–41 (4) Μm ( Fig. 64G ), tibia with single, apical and pectinate spur 14–17 (4) Μm long ( Fig. 64H ), with three lateral teeth and two preapical setae; ta1-4 without any preapical pseudospurs. Mid leg: width at apex of tibia 30–37 Μm long ( Fig. 64I ), tibia with single, apical and pectinate spur 18–23 Μm long with three lateral teeth ( Fig. 64J ) and two preapical setae; ta1-4 each with two preapical pseudospurs. Hind leg: width at apex of tibia 33–37 Μm long ( Fig. 64K ), 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 43.

fe ti ta1 ta2 ta3

p1 407–497 437–531 350–434 211–269 153–212 p2 506–630 407–530 537–716 242–321 144–178 p3 500–557 570–688 624–746 263–333 174–211

ta4 ta5 LR BV SV

p1 106–146 73–81 0.80–0.83 2.08–2.20 2.37–2.41 p2 97–123 63–81 1.31–1.46 2.53–2.74 1.56–1.70 p3 112–122 79–88 1.01–1.08 2.64–2.82 1.67–1.78 Hypopygium ( Fig. 64M ). Tergite IX arched, with 8–11 posterior setae. Membranous anal point rounded, apical edge slightly convex. Phallapodeme 44–54 Μm long. Sternapodeme with much reduced anterior process. Gonocoxite cylindrical, 94–106 (4) Μm long, 45–56 (4) Μm wide, with slightly concave inner margin. GcR 1.88– 2.10 (4). Gonostylus simple and slender, 53–69 Μm long; megaseta 9–12 Μm long. HR 1.61–1.77. HV 3.30–3.55.

Adult female (n = 1)

Size. Total length 1.3 mm. Wing length 1.0 mm. Total length/wing length 1.27. Wing length/ profemur length 2.81.

Coloration. Head pale brown with dark brown occipital margin; pedicel and antenna brown; maxillary

palp pale brown. Thorax brown with dark scutum; antepronotum pale brown; supraalar callus pale brown. Wing membrane transparent without any marking. Legs pale brown. Abdomen brown. Seminal capsules brown.

Head. Temporal setae 10, uniserial. Eyes ratio 0.93. Tentorium 137 Μm long. Clypeus 77 Μm long, 57 Μm wide at largest part, bearing 18 setae. Cibarial pump 193 Μm long, as in male. Lengths of palpomeres 1–4 (in Μm): 35; 48; 98; 124; palpomeres 5 broken off. Antennal flagellum not measurable.

Thorax. Antepronotum with 2 lateral setae. Acrostichals 37, irregularly biserial, starting close to antepronotum; dorsocentrals 30, irregularly uniserial; prealars 10; 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 0.68. WW 0.38. Brachiolum with 2 setae. Squama setiferous.

Legs. Fore leg: width at apex of tibia 42 Μm, tibia with single, apical and pectinate spur 18 Μm long, with three lateral teeth and two preapical setae; ta1-4 without any preapical pseudospurs. Mid leg: width at apex of tibia 34 Μm long, tibia with single, apical and pectinate spur 20 Μm long with three lateral teeth and two preapical setae; ta1-4 each with two preapical pseudospurs. Hind leg: width at apex of tibia 43 Μm long, tibia without spur; comb with 5 bristles; ta1-4 without any preapical pseudospurs. Claws slender, hooked; pulvilli absent. Lengths and proportion of leg segments as in Table 44.

Genitalia. Gonapophysis VIII broadly rounded, 51 Μm long. Coxosternapodeme 59 Μm long. Postgenital plate rounded. Cerci oval-quadrate, 53 Μm long and 15 Μm wide; with 5 elongated setae. Labia with inconspicuous microtrichia. Notum length 96 Μm long. Seminal capsules oval, 46 Μm long, 28 Μm wide, with conical shaped necks. Length ratio SCa/No 0.48.

Pupa (n = 6 unless otherwise stated)

Size. Abdomen 1.7–2.4 mm long in male.

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

fe ti ta1 ta2 ta3

p1 366 383 349 165 122 p2 540 411 494 242 163 p3 456 545 560 206 128

ta4 ta5 LR BV SV p1 92 75 0.91 2.42 2.13 p2 118 90 1.20 2.35 1.92 p3 84 80 1.02 3.13 1.78 Cephalothorax ( Figs 65A–C ). Frontal apotome smooth ( Fig. 65A ). Wing sheath smooth 0.7–1.0 mm long. Thoracic horn 247–307 Μm long and 124–169 Μm wide ( Fig. 65B ), THR 1.75–2.08, preapical indentation moderately deep. Membranous preapical papilla 21–38 Μm long ( Fig. 65C ), PTH 0.07–0.14, aeropyle tube simple, short, 17–26 (3) 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 7–9 conical tubercles ( Fig. 65B ).

Abdomen ( Figs 65D–E ). Tergite I with scar 108–136 Μm long. T I–VI without shagreen, T VII–VIII with shagreen basally concentrated. Abdominal chaetotaxy as in figure 65D. Abdominal segment VII with 3 LS-setae. A VIII with 5 LS-setae. Anal lobe 282–305 (5) Μm long and 131–176 (5) Μm wide ( Fig. 65E ), outer margins sclerotized, with 6–11 spines, longest spine 20–23 (5) Μm long, inner margins of lobes membranous. ALR 2.06– 2.30 (5). Male genital sac not surpassing apex of anal lobe.

4th instar larva (n = 5 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. 66A ). Length 434–525 Μm, 271–323 Μm wide. IC 0.59–0.65. Surface covered with small spinules; lateroventral and posteroventral spine groups absent. Ventral cephalic setae S9 and S10 and SSm forming a straight line diagonal to longitudinal axis of head capsule ( Fig. 66A ).

Antenna ( Figs 66B–C ). Length 253–285 Μm, A1 170–195 Μm long, with ring organ located 0.88 (1) from base, A2 70–80 Μm long. AR 1.93–2.15. Blade longer than A2 over-reached by accessory blade.

Maxilla ( Fig. 66D ). Basal palp segment 22–30 Μm long and 0.56–0.71 Μm wide at the middle, with ring organ located 14–17 (2) from base. PR 2.68–4.15. APR 5.88–7.84.

Mandible ( Fig. 66E ). Length 61–85 Μm. Sensillum campaniformium located 0.64–0.81 from apex, basal tooth bifid, with seta subdentalis projecting from sloping end towards apical tooth, accessory tooth present, AMD 2.25– 2.85.

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

Hypopharyngeal complex ( Figs 66F–G ). Ligula 52–62 Μm long, 25–26 Μm wide, with row of 5 teeth. IO 0.95– 0.99, MO 1.01–1.07. Paraligula bifid, 24–29 Μm long, inner tooth 19–22 Μm long, shorter than outer tooth. Pecten hypopharyngis with 6 teeth almost equal in size.

Body ( Figs 66H–I ). Without lateral fringe. Anterior parapods with simple claws. Procercus 137–165 (4) Μm long, 28–29 Μm wide, with 7 anal setae, 379–448 Μm long. L/ W 4.83 –5.64 (4). Supraanal seta well developed. Anal tubules not measurable. Posterior parapod not measurable; subbasal seta on posterior parapod simple, with 3– 4 small spines basally ( Fig. 66H ); parapod apex with numerous simple claws and one serrated claw; bifid claw with V-shaped lower indentation ( Fig. 66I ). B/C 1.13–1.18 (2).

Remarks. Adult males and immatures of Labrundinia reniformis appear most similar to those of L. parareniformis and differences are discussed under this species. Labrundinia reniformis has been recorded from two localities in São Paulo State, Brazil. The larvae were collected in the Barreiro reservoir, characterized by a predominance of the aquatic macrophyte, Eichhornia azurea . The species was also collected in the Canchin reservoir, a small dam characterized by a predominance of the aquatic macrophyte, Salvinia auriculata .

Figures

FIGURES 64 A – M. Labrundinia reniformis 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 65 A – E. Labrundinia reniformis 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 66 A – J. Labrundinia reniformis 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. Serrated claw of posterior parapod. I. Subbasal seta of posterior parapod. J. Bifid claw of posterior parapod.