Labrundinia mayaca 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 : 73-79

Labrundinia mayaca Silva sp. n.

( Figs 34–36 )

Labrundinia sp. 24 Silva et al. 2013: 602 (DNA barcodes).

Material examined. Type material: Holotype male with pupal and larval exuviae, Brazil: São Paulo, São Carlos, Mayaca reservoir, 20.iv.2011, F. L. Silva ( MZUSP – FA021). 5 Paratypes: 1 male with pupal and larval exuviae same data as holotype ( NTNU); 1 male same data as holotype male except for 11.iv.2011 ( NTNU). 1 female with pupal and larval exuviae same data as holotype except for 11.iv.2011 ( NTNU); 1 female with pupal exuviae same data as holotype ( NTNU); 1 pharate male with larval exuviae same data as holotype ( NTNU).

Etymology. Named after Mayaca , the generic name of the aquatic macrophyte, M. fluviatilis Aublet , in which the holotype was collected associated. The name is to be regarded as a noun in apposition.

Diagnostic characters. Labrundinia mayaca sp. n. differs from other Labrundinia species by the combination of the following characters. Adult male: abdominal tergites I–II pale, T III–VIII with continuous brown transverse band near proximal margin; hypopygium pale, sternapodeme with reduced anterior process. Pupa: thoracic horn shaped like the number ‘9’; shagreen on sternite II with prominent spines; apical spines 18–26 Μm long; male genital sac extending much beyond apex of the anal lobe. Larva: surface of head capsule smooth; lateroventral spine group absent, posteroventral spine group present with 14–22 small spines; AR 3.02–3.22; subbasal seta of posterior parapod simple; bifid claw brown, with U-shaped lower indentation.

Description. Adult male (n = 3 unless otherwise stated)

Size. Total length 2.6–2.7 mm. Wing length 1.3–1.4 mm. Total length/wing length 1.86–1.97. Wing length/ profemur length 2.69–3.03.

Coloration. Head brown with dark brown occipital margin; pedicel and antenna brown; maxillary palp brown. Thorax completely brown; antepronotum pale brown. Wing membrane transparent without any marking. Legs brown. Femur I–III pale brown. Tibia I brown, Ti II pale brown, Ti III pale brown with apex brown. Tarsomere 1– 5 brown. Abdominal tergites I–II pale, T III–VIII with continuous brown transverse band near proximal margin; hypopygium pale ( Fig. 34L ).

Head ( Figs 34A–E ). Temporal setae 11–12, uniserial ( Fig. 34B ). Eye ratio 1.04–1.10. Tentorium ( Fig. 34C ) 157–166 Μm long. Clypeus 71–73 (2) Μm long, 62–66 Μm wide at largest part, bearing 10–16 setae. Cibarial pump 154–193 Μm long ( Fig. 34D ), with anterior margin concave. Lengths of palpomeres 1–4 (in Μm): 26–38; 50–62; 116–131; 124–145; palpomeres 5 broken off. Antennal flagellum 797–856 Μm long, diameter of pedicel 144–165 Μm, apical setae single ( Fig. 34E ),AR 1.21–1.32.

Thorax. Antepronotum with 4 lateral setae. Acrostichals 54–62, biserial, diverging evenly posteriorly, starting close to antepronotum and almost reaching scutellum; dorsocentrals 21–29, irregularly biserial; prealars 12–13; supraalars 3. Anapleural suture ratio 0.45–0.54. Scutellum with transverse row of 8 setae and group of numerous fine anterior setae.

Wing ( Fig. 34F ). Width 0.4 mm. Costa 1.1–1.2 mm long, not produced beyond R4+5. R2+3 present. VR 0.75– 0.78. WW 0.30. Brachiolum with 2 setae. Squama setiferous.

Legs ( Figs 34G–K ). Fore leg: width at apex of tibia 37–38 Μm ( Fig. 34G ), tibia with single, apical and pectinate spur 15–19 Μm long ( Fig. 34H ), with three lateral teeth and two preapical setae; ta1-4 without any preapical pseudospurs. Mid leg: width at apex of tibia 42–44 Μm long ( Fig. 34I ), tibia with single, apical and pectinate spur 19–29 Μm long with three lateral teeth ( Fig. 34J ) and two preapical setae; ta1-4 each with two preapical pseudospurs. Hind leg: width at apex of tibia 38–44 Μm long ( Fig. 34K ), tibia without spur; comb with 5 bristles; ta1-4 each with two preapical pseudospurs. Claws slender, hooked; pulvilli absent. Lengths and proportion of leg segments as in Table 22.

fe ti ta1 ta2 ta3

p1 513–519 466–475 321–344 211–231 143–147 p2 663–694 443–456 625–680 294–313 156–199 p3 531–581 487–669 581–694 281 147

ta4 ta5 LR BV SV

p1 106–110 73–75 0.68–0.69 2.25–2.50 2.79–2.96 p2 100–127 75–78 1.37–1.54 2.46–2.76 1.53–1.84 p3 97 78 0.97 2.83 1.94 Hypopygium ( Fig. 34M ). Tergite IX arched, with 9–12 posterior setae. Membranous anal point trapezoidal, apical edge slightly concave. Phallapodeme 54–60 Μm long. Sternapodeme with reduced anterior process. Gonocoxite cylindrical, 151–153 Μm long, 65–67 Μm wide, with slightly concave inner margin. GcR 2.27–2.34. Gonostylus simple and slender, 84–89 Μm long; megaseta 11–14 Μm long. HR 1.69–1.80. HV 2.90–3.20.

Adult female (n = 2 unless otherwise stated)

Size. Total length 1.5–1.6 mm. Wing length 1.2 mm. Total length/wing length 1.30–1.46. Wing length/length of profemur 1.22–1.35.

Coloration. Head dark brown with dark brown occipital margin; pedicel and antenna brown; maxillary palp pale brown. Thorax completely brown; antepronotum pale brown. Wing membrane transparent without any marking. Legs brown. Femur I–III pale brown. Tibia I brown, Ti II pale brown, Ti III pale brown with apex brown. Tarsomere 1–5 brown. Abdomen pale brown, with dark brown transverse bands near proximal margin, not much distinguishable. Seminal capsules brown.

Head. Temporal setae 12–14, uniserial. Eyes ratio 1.38 (1). Tentorium 132–149 Μm long. Clypeus 84–91 Μm long, 68–69 Μm wide at largest part, bearing 16–18 setae. Cibarial pump 198–205 Μm long, as in male. Lengths of palpomeres 1–5 (in Μm): 34–45; 51–60; 117–118; 198 (1); 218 (1). Antennal flagellum 438–452 Μm long, diameter of pedicel 58–63, AR 0.35–0.40.

Thorax. Antepronotum with 4 lateral setae. Acrostichals 50–52, irregularly biserial, starting close to antepronotum; dorsocentrals 34–36, irregularly biserial; prealars 12; supraalars 3. Scutellum with transverse row of 8 setae and group of numerous fine anterior setae.

Wing. Width 0.4–0.5 mm. Costa 1.00 mm long. R2+3 present. VR 0.62–0.75. WW 0.37–0.39. Brachiolum with 2 setae. Squama setiferous.

Legs. Fore leg: width at apex of tibia 38 Μm, tibia with single, apical and pectinate spur 18–23 Μm long, with four lateral teeth and two preapical setae; ta1-4 without any preapical pseudospurs. Mid leg: width at apex of tibia 44–56 Μm, tibia with single, apical and pectinate spur 14–25 Μm long, with four lateral teeth and two preapical setae; ta1-4 each with two preapical pseudospurs. Hind leg: width at apex of tibia 44 Μm, tibia without spur; comb with 5 bristles; ta1-4 each with two preapical pseudospurs. Lengths and proportion of leg segments as in Table 23.

fe ti ta1 ta2 ta3

p1 318–375 381 300 175 113

p2 594–600 475–481 588–594 238–244 125–138 p3 506–513 581–625 575 244 131

ta4 ta5 LR BV SV

p1 88 69 0.79 2.38 2.52 p2 88–113 69–75 1.23–1.24 3.02–3.10 1.81–1.83 p3 94 81 0.99 3.02 1.89 Genitalia. Gonapophysis VIII broadly rounded, 51–57 Μm long. Coxosternapodeme 63–81 Μm long. Postgenital plate rounded. Cerci oval-quadrate, 54–66 Μm long and 17–18 Μm wide; with 8–10 elongated setae. Labia with inconspicuous microtrichia. Notum length 97–117 Μm long. Seminal capsules oval, 40–48 Μm, 29– 45Μm wide, with conical shaped necks. Length ratio SCa/No 0.41.

Pupa (n = 5 unless otherwise stated)

Size. Abdomen 2.3–2.4 (3) mm long in male, 2.2–2.3 (2) mm long in female.

Coloration. Exuviae and thoracic horn brown.

Cephalothorax ( Figs 35A–C ). Frontal apotome smooth ( Fig. 35A ). Wing sheath smooth 0.8–0.9 mm long. Thoracic horn 231–300 Μm long and 100–131 Μm wide ( Fig. 35B ), THR 2.21–2.40, preapical indentation deep. Membranous preapical papilla 28–40 Μm long ( Fig. 35C ), PTH 0.09–013, aeropyle tube simple, elongated and slender, 45–72 (4) 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 7–9 conical tubercles ( Fig. 35B ).

Abdomen ( Figs 35D–F ). Tergite I with scar 130–138 (4) Μm long. T I–VI without shagreen, T VII–VIII with shagreen basal concentrated. Sternite II with prominent spines ( Fig. 35D ). Abdominal chaetotaxy as in figure 35E. Abdominal segment VII with 4 LS-setae. A VIII with 5 LS-setae. Anal lobe 331–344 (4) Μm long and 194–213 (4) Μm wide ( Fig. 35F ), outer margins sclerotized, with 10–12 spines, longest spine 18–26 Μm long, inner margins of lobes membranous. ALR 1.56–1.75 (4). Male genital sac extending much beyond apex of anal lobe.

4th instar larva (n = 4 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 to pale brown except for bifid claw brown.

Head ( Fig. 36A ). Length 506–600 Μm, 319 (3) Μm wide. IC 0.49–0.63. Surface smooth; lateroventral spine group absent; posteroventral spine group present with 14–22 (3) small spines. Ventral cephalic setae S9, S10 and VP forming a right angle ( Fig. 36A ).

Antenna ( Figs 36B–C ). Length 320–335 (3) Μm, A1 240–256 (3) Μm long, with ring organ located 0.69–0.90 (2) from base, A2 65–72 Μm long. AR 3.02–3.22. Blade longer than A2 over-reached by accessory blade.

Maxilla ( Fig. 36D ). Basal palp segment 31–33 Μm long and 7–8 Μm wide at the middle, with ring organ located 0.61–0.81 from base. PR 3.94–4.34. APR 7.30–7.74.

Mandible ( Fig. 36E ). Length 63–80 Μm. Sensillum campaniformium located 0.71–0.80 from apex, basal tooth bifid, with seta subdentalis projecting from sloping end towards apical tooth, accessory tooth present, AMD 3.39– 3.80 (3).

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

Hypopharyngeal complex ( Figs 36F–G ). Ligula 61–73 Μm long, 28–32 Μm wide, with row of 5 teeth. IO 0.84– 0.93, MO 0.99. Paraligula bifid, 27–31 Μm long, inner tooth 20–27 Μm long, shorter than outer tooth. Pecten hypopharyngis with 7 teeth almost equal in size.

Body ( Figs 36H–I ). Without lateral fringe. Anterior parapods with simple claws. Procercus 192–213 (3) Μm long, 31–32 (3) Μm wide, with 7 anal setae 381–184 (2) Μm long. L/ W 5.95 –6.80 (3). Supraanal seta well developed. Anal tubules 351 (1) Μm long. Posterior parapod 451 (1) Μm long; subbasal seta on posterior parapod simple, without conspicuous spines ( Fig. 36H ); parapod apex with numerous simple claws; bifid claw with Ushaped lower indentation ( Fig. 36I ). B/C 1.23–1.26.

Remarks. Adult males of Labrundinia mayaca appear most similar to those of L. fera in the abdominal coloration. However, the completely brown abdominal tergites VI–VIII and the pale hypopygium in L. mayaca contrast the banded abdominal tergites VI–VIII and the partly brown hypopygium (apical ½) in L. fera . The pupae of L. mayaca are very similar to those of L. paravirescens , but can be distinguished from this species by having simple or bifid spinules and shorter apical spines in the shagreen on sternite II. The larvae of L. mayaca appear most similar to those of L. carolae and were fully discussed on the remarks of the latter. Labrundinia mayaca and L. paravirescens can also be separated by their COI gene sequences ( Silva et al. 2013). Labrundinia mayaca has been recorded only from its type locality. The larvae were collected associate with the aquatic macrophyte, Mayaca fluviatilis , in a small reservoir surrounded by riparian vegetation. The water has a medium level of dissolved oxygen, with pH around 7.0 and the reservoir bed is characterized by a predominance of M. fluviatilis in decomposition.

Figures

FIGURES 34 A – M. Labrundinia mayaca 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 35 A – F. Labrundinia mayaca 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 36 A – I. Labrundinia mayaca 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.