Labrundinia semicurvata, Silva, Fabio Laurindo Da, Fonseca-Gessner, Alaide Aparecida & Ekrem, Torbjørn, 2014

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 : 145-149

publication ID	https://doi.org/ 10.11646/zootaxa.3769.1.1
publication LSID	lsid:zoobank.org:pub:705567C6-C912-4A19-9DE2-726254E17076
DOI	https://doi.org/10.5281/zenodo.5621091
persistent identifier	https://treatment.plazi.org/id/676987A8-B792-FF45-FF29-FF6CFD12FB5B
treatment provided by	Plazi
scientific name	Labrundinia semicurvata
status	sp. nov.

Treatment

Labrundinia semicurvata View in CoL sp. n.

( Figs 70–71 View FIGURES 70 A – M View FIGURES 71 A – J )

Labrundinia View in CoL sp. 20 Silva et al. 2013: 601 (DNA barcodes).

Material examined. Type material: Holotype male, Brazil: São Paulo, São Carlos, Monjolinho stream, associated with the aquatic macrophyte Myriophyllum aquaticum , 11.iv.2011, F. L. Silva ( MZUSP – FA049 (1)). 2 Paratypes: 1 pharate pupa with larval exuviae same data as holotype ( NTNU). 1 female with larval exuviae same data as holotype ( NTNU).

Etymology. Derived from the Latin semicurvatus, referring to the arched shape of the ventral spot on larval cephalic capsule.

Diagnostic characters. Labrundinia semicurvata sp. n. differs from other Labrundinia species by the combination of the following characters. Adult male: wing length 1.21 mm; abdominal tergite I pale, T II, IV, VI with continuous brown transverse band near proximal margin, T III, VII–VIII completely brown; hypopygium pale, sternapodeme with distinct anterior process. Pupa: thoracic horn club-shaped, preapical papilla ratio 0.34, aeropyle tube ending in a small conical expansion. Larva: surface of head capsule covered with small spinules, with ventral semicircular spot; lateroventral and posteroventral spine groups absent; subbasal seta of posterior parapod simple; bifid claw with U-shaped lower indentation.

Description. Adult male (n = 1)

Size. Total length 2.2 mm. Wing length 1.2 mm. Total length/wing length 1.83. Wing length/length of profemur 2.49.

Coloration. Head dark brown to black with dark brown occipital margin; pedicel and antenna brown; maxillary palp pale brown. Thorax completely dark brown. Wing membrane transparent without any marking. Legs pale brown. Abdominal tergite I pale, T II, IV, VI with continuous brown transverse band near proximal margin, T III, VII–VIII completely brown; hypopygium pale ( Fig. 70L View FIGURES 70 A – M ).

Head ( Figs 70A–E View FIGURES 70 A – M ). Temporal setae 11, uniserial ( Fig. 70B View FIGURES 70 A – M ). Eye ratio 1.58. Tentorium ( Fig. 70C View FIGURES 70 A – M ) 144 Μm long. Clypeus 76 Μm long, 67 Μm wide at largest part, bearing 17 setae. Cibarial pump 180 Μm long ( Fig. 70D View FIGURES 70 A – M ), with anterior margin concave. Lengths of palpomeres 1–5 (in Μm): 35; 57; 115; 120; 204. Antennal flagellum 742 Μm long, diameter of pedicel 123 Μm, apical setae single ( Fig. 70E View FIGURES 70 A – M ), AR 1.08.

Thorax. Antepronotum lateral setae not observed. Acrostichals 44, biserial, diverging evenly posteriorly, starting close to antepronotum and almost reaching scutellum; dorsocentrals 20, irregularly biserial; prealars 8; supraalars 2. Anapleural suture ratio 0.31. Scutellum with transverse row of 7 setae and group of numerous fine anterior setae.

Wing ( Fig. 70F View FIGURES 70 A – M ). Width 0.4 mm. Costa 1.0 mm long. R2+3 present. VR 0.75. WW 0.30. Brachiolum with 2 setae. Squama setiferous.

Legs ( Figs 70G–K View FIGURES 70 A – M ). Fore leg: width at apex of tibia 32 Μm ( Fig. 70G View FIGURES 70 A – M ), tibia with single, apical and pectinate spur 10 Μm long ( Fig. 70H View FIGURES 70 A – M ), with three lateral teeth and two preapical setae; preapical pseudospurs not observed. Mid leg: width at apex of tibia 35 Μm long ( Fig. 70I View FIGURES 70 A – M ), tibia with single, apical and pectinate spur 21 Μm long with three lateral teeth ( Fig. 70J View FIGURES 70 A – M ) and two preapical setae; preapical pseudospurs not observed. Hind leg: width at apex of tibia 32 Μm long ( Fig. 70K View FIGURES 70 A – M ), tibia without spur; comb with 6 bristles; preapical pseudospurs not observed. Lengths and proportion of leg segments as in Table 47.

fe ti ta1 ta2 ta3 p1 405 446 – – – p2 553 447 – – – p3 484 609 – – –

ta4 ta5 LR BV SV p1 – – – – – p2 – – – – – p3 – – – – – Hypopygium ( Fig. 70M View FIGURES 70 A – M ). Tergite IX arched, with 9 posterior setae. Membranous anal point triangular, apical edge slightly notched. Phallapodeme 41 Μm long. Sternapodeme with distinct anterior process. Gonocoxite cylindrical, 122 Μm long, 56 Μm wide, with slightly concave inner margin. GcR 2.19. Gonostylus simple and slender, 74 Μm long; megaseta 11 Μm long. HR 1.66. HV 3.00.

Adult female (n = 1)

Size. Total length 1.4 mm. Wing length 0.9 mm. Total length/wing length 1.47. Wing length/ profemur length 2.78.

Coloration. Head dark brown to black with dark brown occipital margin; pedicel and antenna brown; maxillary palp pale brown. Thorax completely dark brown. 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 1.37. Tentorium 126 Μm long. Clypeus 71 Μm long, 59 Μm wide at largest part, bearing 15–18 setae. Cibarial pump 182 Μm long, as in male. Lengths of palpomeres 1–4 (in Μm): 33; 43; 92; 106; palpomeres 5 broken off. Antennal flagellum 325 Μm long, diameter of pedicel 57 Μm, AR 0.42.

Thorax. Antepronotum lateral setae not observed. Acrostichals 44, irregularly biserial, starting close to antepronotum; dorsocentrals 20, irregularly biserial; prealars 11; supraalars 2. Scutellum with transverse row of 8 setae and group of numerous fine anterior setae.

Wing. Width 0.4 mm. Costa 0.8 mm long. R2+3 present. VR 0.74. WW 0.39. Brachiolum with 2 setae. Squama setiferous.

Legs. Fore leg: width at apex of tibia 31 Μm, tibia with single, apical and pectinate spur 15 Μm long, with three lateral teeth and two preapical setae; preapical pseudospurs on ta1-4 not observed. Mid leg: width at apex of tibia 35 Μm, tibia with single, apical and pectinate spur 17 Μm long, with three lateral teeth and two preapical setae; preapical pseudospurs on ta1-4 not observed. Hind leg: width at apex of tibia 38 Μm, tibia without spur; comb with 6 bristles; preapical pseudospurs on ta1-4 not observed. Lengths and proportion of leg segments as in Table 48.

fe ti ta1 ta2 ta3 p1 337 328 – – – p2 463 401 – – – p3 427 492 – – –

ta4 ta5 LR BV SV p1 – – – – – p2 – – – – – p3 – – – – – Genitalia. Gonapophysis VIII broadly rounded, 52 Μm long. Coxosternapodeme 71 Μm long. Postgenital plate rounded. Cerci oval-quadrate, 37 Μm long and 14 Μm wide; with 8 elongated setae. Labia with inconspicuous microtrichia. Notum length 70 Μm long. Seminal capsules oval, 32 Μm long, 30 Μm wide, with conical shaped necks. Length ratio SCa/No 0.46.

Pupa (n = 1)

Size. Abdomen not measurable.

Coloration. Thoracic horn brown.

Cephalothorax ( Figs 71A View FIGURES 71 A – J ). Thoracic horn 138 Μm long and 35 Μm wide ( Fig. 71A View FIGURES 71 A – J ), THR 3.91, preapical indentation moderately deep. Membranous preapical papilla 46 Μm long, PTH 0.34, aeropyle tube simple, short and robust, 11 Μm long, ending in a small conical expansion; 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. 71A View FIGURES 71 A – J ).

Abdomen. Missing.

4th instar larva (n = 2 unless otherwise stated)

Coloration. Head pale yellow, with ventral semicircular 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. 71B View FIGURES 71 A – J ). Length 453–458 Μm, 316–365 Μm wide. IC 0.70–0.80. Surface covered with small spinules; lateroventral and posteroventral spine groups absent. Ventral cephalic setae S9, S10 and SSm forming a more or less straight line perpendicular to longitudinal axis of head capsule ( Fig. 71B View FIGURES 71 A – J ).

Antenna ( Figs 71C–D View FIGURES 71 A – J ). Length 234–242 Μm, A1 166–172 Μm long, with ring organ located 0.85–0.86 Μm from base, A2 58–59 long. AR 2.43–2.45. Blade longer than A2 over-reached by accessory blade.

Maxilla ( Fig. 71E View FIGURES 71 A – J ). Basal palp segment 23–24 Μm long and 7–8 Μm wide at the middle, with ring organ located 0.81–0.84 from base. PR 2.80–3.22. APR 7.02–7.57.

Mandible ( Fig. 71F View FIGURES 71 A – J ). Length 66–72 Μm. Sensillum campaniformium located 0.74–0.82 from apex, basal tooth bifid, with seta subdentalis projecting from sloping end towards apical tooth, accessory tooth present, AMD 2.40– 2.51.

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

Hypopharyngeal complex ( Figs 71G–H View FIGURES 71 A – J ). Ligula 54–59 Μm long, 26 Μm wide, with row of 5 teeth. IO 0.95– 0.98, MO 1.05–1.07. Paraligula bifid, 25–27 Μm long, inner tooth 19 Μm long, shorter than outer

tooth. Pecten hypopharyngis with 6 teeth almost equal in size.

Body ( Figs 71I –J View FIGURES 71 A – J ). Without lateral fringe. Anterior parapods with simple claws. Procercus 88–92 Μm long, 26– 27 Μm wide, with 7 anal setae 380 (1) Μm long. L/ W 3.27 –3.53. Supraanal seta well developed. Anal tubules not measurable. Posterior parapod 223 (1) Μm long; subbasal seta on posterior parapod simple, with 2–3 small spines basally ( Fig. 71I View FIGURES 71 A – J ); parapod apex with numerous simple claws; bifid claw with U-shaped lower indentation ( Fig. 71J View FIGURES 71 A – J ). B/C 0.90–1.04.

Remarks. Adult males of L. semicurvata appear most similar to those of L. pilosella and differences are discussed under this species. The pupae of L. semicurvata are very similar to those of L. sofiae , but can be distinguished by lateral indentation on external margin of the thoracic horn and the aeropyle tube ending in a small conical expansion, which contrast with the smooth margin of the thoracic horn and the aeropyle tube ending in a bulbous expansion in L. sofiae . The distinctive arched shape of the ventral maculation on the cephalic capsule distinguishes the larvae of L. semicurvata from any known Labrundinia species. Labrundinia semicurvata has been recorded only from its type locality in São Paulo State, Brazil. The larvae were collected associated with the aquatic macrophyte Myriophyllum aquaticum .