Labrundinia fiorelinii 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 : 33-39

Labrundinia fiorelinii Silva sp. n.

( Figs 13–15 )

Labrundinia sp. 7 Silva et al. 2013: 601 (DNA barcodes).

Material examined. Type material: Holotype male with pupal and larval exuviae, Brazil: São Paulo, Gália, Caetetus Ecological Station, Barreiro reservoir, 8.vii.2008, F. L. Silva & J. F. Nunes ( MZUSP). 3 Paratypes: 2 males with pupal and larval exuviae same data as holotype ( NTNU). 1 female with pupal and larval exuviae same data as holotype ( NTNU).

Etymology. Named in honour of Juliano Fiorelini Nunes for his friendship and camaraderie in the field.

Diagnostic characters. Labrundinia fiorelinii sp. n. differs from other Labrundinia species by the combination of the following characters. Adult male:wing length 1.6 mm; abdominal tergite II–V with continuous brown transverse band near proximal margin, T VI–VIII almost completely brown; hypopygium pale brown, sternapodeme with moderate anterior process. Pupa: thoracic horn kidney-shaped, preapical indentation very reduced; abdominal segment VII with 4 LS-setae. Larva: head capsule surface covered with small spinules, ventral maculation; lateroventral and posteroventral spine groups absent; subbasal seta simple; posterior parapod without serrated claw; bifid claw with V-shaped lower indentation.

Description. Adult male (n = 3)

Size. Total length 2.6–3.0 mm. Wing length 1.6 mm. Total length/wing length 1.61–1.87. Wing length/ profemur length 2.81–3.16.

Coloration. Head 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–V with continuous brown transverse band near proximal margin, T VI–VIII almost completely brown; hypopygium pale brown ( Fig. 13L ).

Head ( Figs 13A–E ). Temporal setae 12, uniserial ( Fig. 13B ). Eye ratio 0.97–1.01. Tentorium ( Fig. 13C ) 150– 179 Μm long. Clypeus 88–114 Μm long, 66–71 Μm wide at largest part, bearing 13–17 setae. Cibarial pump 216– 232 Μm long ( Fig. 13D ), with anterior margin concave. Lengths of palpomeres 1–4 (in Μm): 42–47; 60–95; 131– 151; 159–165; palpomeres 5 broken off. Antennal flagellum 904–945 Μm long, diameter of pedicel 144–154 Μm, apical setae single ( Fig. 13E ), AR 1.44–1.50.

Thorax. Antepronotum with 2–4 lateral setae. Acrostichals 34–40, biserial, diverging evenly posteriorly, starting close to antepronotum and almost reaching scutellum; dorsocentrals 22, irregularly biserial; prealars 7–9; supraalars 2. Anapleural suture ratio 0.38–0.45. Scutellum with transverse row of 9–10 setae and group of numerous fine anterior setae.

Wing ( Fig. 13F ). Width 0.4–0.5 mm. Costa 1.4–1.5 mm long. R2+3 absent. VR 0.70–0.75. WW 0.27–0.30. Brachiolum with 2 setae. Squama setiferous.

Legs ( Figs 13G–K ). Fore leg: width at apex of tibia 44–47 Μm ( Fig. 13G ), tibia with single, apical and pectinate spur 16–25 Μm long ( Fig. 13H ), with three lateral teeth and two preapical setae; ta1-4 without any preapical pseudospurs. Mid leg: width at apex of tibia 42–50 Μm long ( Fig. 13I ), tibia with single, apical and pectinate spur 25–29 Μm long with three lateral teeth ( Fig. 13J ) and two preapical setae; ta1-4 each with two preapical pseudospurs. Hind leg: width at apex of tibia 38–49 (2) Μm long ( Fig. 13K ), 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 10.

fe ti ta1 ta2 ta3

p1 529–562 609–623 495–523 313–330 232–239 p2 656–694 588–599 773–862 340–402 193–211 p3 636–649 799–826 822–846 388–392 247–251

ta4 ta5 LR BV SV

p1 130–155 87–97 0.81–0.85 2.10–2.12 2.24–2.30 p2 128–132 94–101 1.31–1.43 2.46–2.69 1.47–1.65 p3 154–156 89–107 1.02–1.03 2.54–2.59 1.74–1.75 Hypopygium ( Fig. 13M ). Tergite IX arched, with 10 posterior setae. Membranous anal point small, apical edge slightly notched. Phallapodeme 52–56 Μm long. Sternapodeme with moderate anterior process. Gonocoxite cylindrical, 112–116 Μm long, 44–48 Μm wide, with slightly concave inner margin. GcR 2.46– 2.54. Gonostylus simple and slender, 74–77 Μm long; megaseta 12 (2) Μm long. HR 1.50–1.52. HV 3.40–4.09. Adult female (n = 1)

Size. Total length 1.9 mm. Wing length 1.1 mm. Total length/wing length 1.66. Wing length/ profemur length 2.51.

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 pale brown. Abdomen pale brown, with brown transverse bands near proximal margin. Seminal capsules brown.

Head. Temporal setae 10, uniserial. Eyes ratio 1.50. Tentorium 141 Μm long. Clypeus 104 Μm long, 84 Μm wide at largest part, bearing 25 setae. Cibarial pump 219 Μm long, as in male. Lengths of palpomeres 1–5 (in Μm): 41; 80; 129; 150; 241. Antennal flagellum 331–319 Μm long, diameter of pedicel 55 Μm, AR 0.91.

Thorax. Antepronotum with 2 lateral setae. Acrostichals 44, irregularly biserial, starting close to antepronotum; dorsocentrals 40, irregularly biserial; prealars 11; supraalars 2. Scutellum with transverse row of 12 setae and group of numerous fine anterior setae.

Wing. Width 0.5 mm. Costa 1.1 mm long. R2+3 absent. VR 0.70. WW 0.44. Brachiolum with 2 setae. Squama setiferous.

Legs. Fore leg: width at apex of tibia 48 Μm, tibia with single, apical and pectinate spur 21 Μm, with three lateral teeth and two preapical setae; ta1-4 without any preapical pseudospurs. Mid leg: width at apex of tibia 46 Μm long, tibia with single, apical and pectinate spur 26 Μm long with three lateral teeth and two preapical setae; ta1-4 each with two preapical pseudospurs. Hind leg: width at apex of tibia 42 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 11.

fe ti ta1 ta2 ta3

p1 455 507 415 257 171 p2 651 581 739 306 170 p3 581 728 721 328 212

ta4 ta5 LR BV SV p1 120 78 0.82 2.20 2.31 p2 116 81 1.27 2.93 1.67 p3 138 79 0.99 2.68 1.81 Genitalia. Gonapophysis VIII broadly rounded, 46 Μm long. Coxosternapodeme 91 Μm long. Postgenital plate rounded. Cerci oval-quadrate, 22 Μm long and 13 Μm wide; with 5 elongated setae. Labia with inconspicuous microtrichia. Notum length 103 Μm long. Seminal capsules oval, 44 Μm long, 36 Μm wide, with conical shaped necks. Length ratio SCa/No 0.42.

Pupa (n = 4 unless otherwise stated)

Size. Abdomen 2.6 (3) mm long in male, 2.0 (1) mm long in female.

Coloration. Exuviae mostly pale brown; thoracic horn brown. Abdomen with median brown maculation. Apex of anal lobe brown.

Cephalothorax ( Figs 14A–C ). Frontal apotome smooth ( Fig.14A ). Wing sheath smooth 0.9–1.0 mm long. Thoracic horn 329–379 Μm long and 197–220 Μm wide ( Fig. 14B ), THR 1.67–1.72, preapical absent. Membranous preapical papilla 41–53 Μm long ( Fig. 14C ), PTH 0.12–0.16, aeropyle tube simple, short, 23–38 Μm long; plastron plate small. Horn sac well developed, completely filling respiratory atrium. Reticulation of respiratory atrium indistinct, external membrane with pale spinules basally concentrated. Basal lobe wedge-shaped. Thoracic comb with 8–9 conical tubercles ( Fig. 14B ).

Abdomen ( Figs 14D–E ). Tergite I with scar 163–180 (2) Μm long. T I–VI without shagreen, T VII–VIII with shagreen basal concentrated. Abdominal chaetotaxy as in figure 14D. Abdominal segment VII with 4 LS-setae. A VIII with 5 LS-setae. Anal lobe 361–409 Μm long and 188–224 Μm wide ( Fig. 14E ), outer margins sclerotized, with 6–9 spines, longest spine 19–29 Μm long, inner margins of lobes membranous. ALR 1.65–2.18. Male genital sac not surpassing apex of anal lobe.

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

Coloration. Head pale yellow, with variable brown 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. 15A ). Length 526–563 Μm, 359–369 Μm wide. IC 0.64–0.69. Surface covered with small spinules; lateroventral and posteroventral spine groups absent. Ventral cephalic setae S9, S10 and SSm forming a straight line diagonal to longitudinal axis of head capsule ( Fig. 15A ).

Antenna ( Figs 15B–C ). Length 320–335 Μm, A1 230–240 Μm long, with ring organ located 0.77–0.86 from base, A2 85–88 Μm long. AR 2.24–2.54. Blade longer than A2 over-reached by accessory blade.

Maxilla ( Fig. 15D ). Basal palp segment 24–27 Μm long and 9–10 Μm wide at the middle, with ring organ located 0.72–0.82 from base. PR 2.72–3.08. APR 8.48–9.38.

Mandible ( Fig. 15E ). Length 63–82 Μm. Sensillum campaniformium located 0.65–0.69 from apex, basal tooth bifid, with seta subdentalis projecting from sloping end towards apical tooth, accessory tooth present, AMD 2.81– 3.52.

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

Hypopharyngeal complex ( Figs 15F–G ). Ligula 53–56 Μm long, 26–31 Μm wide, with row of 5 teeth. IO 0.98– 0.99, MO 1.00–1.06. Paraligula bifid, 30–31 Μm long, inner tooth 25–30 Μm long, shorter than outer tooth. Pecten hypopharyngis with 11 teeth almost equal in size.

Body ( Figs 15H–I ). Without lateral fringe. Anterior parapods with simple claws. Procercus 163–208 Μm long, 34–40 Μm wide, with 7 anal setae, 564–723 (3) Μm long. L/ W 4.65 –5.68. Supraanal seta well developed. Anal tubules not measurable. Posterior parapod not measurable; subbasal seta on posterior parapod simple, without spines ( Fig. 15H ); parapod apex with numerous simple claws; bifid claw with V-shaped lower indentation ( Fig. 15I ). B/C 1.11–1.21 (3).

Remarks. Adult males of Labrundinia fiorelinii are most similar to those of L. parareniformis and L. reniformis in the length of the tentorium and the coloration of the hypopygium, but they differ in the slightly larger size (wing length 1.6 mm opposed to 1.2–1.3 mm) and by having a notched membranous anal point. The pupae of L. fiorelinii also resemble those of L. parareniformis and L. reniformis , but can be distinguished by the missing preapical indentation in the thoracic horn and the presence of 4 LS-setae on abdominal segment VII. The larvae are apparently most similar to those of L. semicurvata , but may be distinguished by the ventral maculation covering almost half of the surface of the head capsule and V-shaped lower indentation on the bifid claw of the posterior parapods. Labrundinia fiorelinii has been recorded only from its type locality in São Paulo State, Brazil. The larvae were collected in small reservoir surrounded by a well-preserved riparian forest. The reservoir is characterized by a predominance of the aquatic macrophyte, Eichhornia azurea .

Figures

FIGURES 13 A – M. Labrundinia fiorelinii 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 14 A – E. Labrundinia fiorelinii 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 15 A – I. Labrundinia fiorelinii 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.