Labrundinia separata ( Edwards, 1931 )

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 : 149-155

Labrundinia separata ( Edwards, 1931)

( Figs 72–74 )

Pentaneura separata Edwards, 1931: 252 (description of adults).

Labrundinia separata ( Edwards, 1931) ; Siri and Donato 2011: 76 (description of adults and immatures).

Material examined. Type material: Holotype male, Argentina: Río Negro, Lago Nahuel Huapi, 28–31.x.1926, F.W. Edwards ( BMNH 950647).

Additional material: 1 female with pupal and larval exuviae, Argentina: Río Negro, Mallín La Heladera, 10.ii.2009, A. Siri (FCNyM). 2 pupae as previous (FCNyM). 1 larva as previous (FCNyM). 4 males, Chile: South, SA 78, G. Kuschel ( ZSM).

Diagnostic characters. Labrundinia separata differs from other Labrundinia species by the combination of the following characters. Adult male: abdominal tergite I pale brown, T II–V with continuous brown transverse band near proximal margin, T VI–VIII completely brown; hypopygium brown, sternapodeme with distinct anterior process. Pupa: thoracic horn wedge-shaped, preapical indentation absent; shagreen on sternite II with prominent spines. Larva: surface of head capsule covered with spinules, lateroventral and posteroventral spine groups absent; AR about 2.11; subbasal seta of posterior parapod simple; bifid claw with V-shaped lower indentation.

Description. Adult male (n = 5)

Size. Total length 2.9–3.1 mm. Wing length 1.8–2.2 mm. Total length/wing length 1.36–1.64. Wing length/ profemur length 2.36–3.19.

Coloration. Head dark brown to black with dark brown occipital margin; pedicel and antenna brown; maxillary palp pale brown. Thorax pale brown with dark scutum; antepronotum pale brown. Wing membrane transparent without any marking. Legs brown. Abdominal tergite I pale brown, T II–V with continuous brown transverse band near proximal margin, T VI–VIII completely brown; hypopygium brown ( Fig. 72L ).

Head ( Figs 72A–E ). Temporal setae 20–27, multiserial ( Fig. 72B ). Eye ratio 0.81–1.45 (4). Tentorium ( Fig. 72C ) 155–174 Μm long. Clypeus 100–165 Μm long, 74–87 Μm wide at largest part, bearing 15–22 setae. Cibarial pump 189–280 Μm long ( Fig. 72D ), with anterior margin concave. Lengths of palpomeres 1–5 (in Μm): 29–38; 65– 88; 106–154; 112–169 (3); 231–275 (2). Antennal flagellum 778–988 (3) Μm long, diameter of pedicel 123–152 (4) Μm, apical setae single ( Fig. 72E ), AR 1.14–1.29 (3).

Thorax. Antepronotum with 4–6 (3) lateral setae. Acrostichals 34–52, biserial, diverging evenly posteriorly, starting close to antepronotum and almost reaching scutellum; dorsocentrals 30–42, irregularly biserial; prealars 9– 17; supraalars 4–5. Anapleural suture ratio 0.40–0.56 (2). Scutellum with transverse row of 10–12 setae and group of numerous fine anterior setae.

Wing ( Fig. 72F ). Width 0.5–0.6 mm. Costa 1.6–2.0 mm long. R2+3 present. VR 0.61–0.71. WW 0.27–0.28. Brachiolum with 2 setae. Squama setiferous.

Legs ( Figs 72G–K ). Fore leg: width at apex of tibia 44–66 Μm ( Fig. 72G ), tibia with single, apical and pectinate spur 18–28 (4) Μm long ( Fig. 72H ), with three lateral teeth and two preapical setae; ta1-4 without any preapical pseudospurs. Mid leg: width at apex of tibia 38–60 Μm long ( Fig. 72I ), tibia with single, apical and pectinate spur 23–30 (4) Μm long with three lateral teeth ( Fig. 72J ) and two preapical setae; ta1-4 each with two preapical pseudospurs. Hind leg: width at apex of tibia 44–61 Μm long ( Fig. 72K ), tibia without spur; comb indistinct; ta1-4 without any preapical pseudospurs. Claws slender, hooked; pulvilli absent. Lengths and proportion of leg segments as in Table 49.

fe ti ta1 ta2 ta3

p1 694–857 650–838 575–583 350–363 222–250 p2 694–956 813–938 325–431 200–250 131–181 p3 763–888 863–1219 932–1069 436–450 296–306

ta4 ta5 LR BV SV

p1 156 75 0.69–0.70 2.72 2.93

p2 131–181 100–131 0.78–1.04 2.46–3.12 2.00–2.40 p3 180–206 131–111 0.82–1.24 2.78–2.80 2.08–2.04 Hypopygium ( Fig. 72M ). Tergite IX arched, with 11–16 posterior setae. Membranous anal point small, apical edge rounded. Phallapodeme 62–93 Μm long. Sternapodeme with distinct anterior process. Gonocoxite cylindrical, 164–173 (4) Μm long, 58– 70 (4) Μm wide, with slightly concave inner margin. GcR 2.31–2.89. Gonostylus simple and slender, 95–106 Μm long; megaseta 12–15 Μm long. HR 1.64–1.75. HV 2.84–3.05.

Adult female (n = 1)

Size. Total length 2.6 mm. Wing length 1.6 mm. Total length/wing length 1.62. Wing length/ profemur length 3.11.

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. Wing membrane transparent without any marking. Legs pale brown. Abdomen completely dark brown. Seminal capsules brown.

Head. Temporal setae 12, uniserial. Eyes ratio 1.93. Tentorium 100 Μm long. Clypeus 99 Μm long, 74 Μm wide at largest part, bearing 18 setae. Cibarial pump 187 Μm long, as in male. Lengths of palpomeres 1–5 (in Μm): 43; 58; 107; 113; 244. Antennal flagellum 538 Μm long, diameter of pedicel 55 Μm, AR 0.37.

Thorax. Antepronotum with 4 lateral setae. Acrostichals 46, irregularly uniserial, starting close to antepronotum; dorsocentrals 36, irregularly biserial; prealars 17; supraalars 5. Scutellum with transverse row of 12 setae and group of numerous fine anterior setae.

Wing. Width 0.6 mm. Costa 0.8 mm long. R2+3 present. VR 0.63. WW 0.35. Brachiolum with 2 setae. Squama setiferous.

Legs. Fore leg: width at apex of tibia 37 Μm, tibia with single, apical and pectinate spur 17 Μm, with three lateral teeth and two preapical setae; preapical pseudospurs on ta1-4 not observed. Mid leg: width at apex of tibia 47 Μm, tibia with single, apical and pectinate spur 23 Μm, with three lateral teeth and two preapical setae; preapical pseudospurs on ta1-4 not observed. Hind leg: width at apex of tibia 40 Μm long, tibia without spur; comb indistinct; preapical pseudospurs on ta1-4 not observed. Claws slender, hooked; pulvilli absent. Lengths and proportion of leg segments as in Table 50.

fe ti ta1 ta2 ta3

p1 505 540 422 260 181 p2 720 559 566 288 175 p3 636 802 699 338 233

ta4 ta5 LR BV SV p1 126 92 0.78 2.22 2.48 p2 107 92 1.01 2.78 2.26 p3 136 100 0.87 2.64 2.06 Genitalia. Gonapophysis VIII broadly rounded, 72 Μm long. Coxosternapodeme 80 Μm long. Postgenital plate rounded. Cerci oval-quadrate, 44 Μm long and 17 Μm wide; with 10 elongated setae. Labia with inconspicuous microtrichia. Notum length 125 Μm long. Seminal capsules oval, 41 Μm long, 37 Μm wide, with conical shaped necks. Length ratio SCa/No 0.33.

Pupa (n = 3 unless otherwise stated)

Size. Abdomen 2.3 (2) mm long in male, 2.3 (1) mm long in female.

Coloration. Exuviae and thoracic horn brown. Apex of anal lobe brown.

Cephalothorax ( Figs 73A–C ). Frontal apotome smooth ( Fig.73A ). Wing sheath smooth 0.7–1.0 mm long. Thoracic horn 285–293 Μm long and 156–187 Μm wide ( Fig. 73B ), THR 1.54–1.82, preapical indentation absent. Membranous preapical papilla 45–52 Μm long ( Fig. 73C ), PTH 0.15–0.18, aeropyle tube simple, short, 27–31 Μm long; plastron plate small. Horn sac well developed, completely filling respiratory atrium. Reticulation of respiratory atrium indistinct, external membrane with pale spinules, almost reaching apex of thoracic horn. Basal lobe wedge-shaped. Thoracic comb with 11–12 conical tubercles ( Fig. 73B ).

Abdomen ( Figs 73D–F ). Tergite I with scar 155–168 Μm long. T I–VI without shagreen, T VII–VIII with shagreen basal concentrated. Sternite II with dense, prominent spines ( Fig. 73D ). Abdominal chaetotaxy as in figure 73E. Abdominal segment VII with 4 LS-setae. A VIII with 5 LS-setae. Anal lobe 304–349 Μm long and 146–152 Μm wide ( Fig. 73F ), outer margins sclerotized, with 13–18 spines, longest spine 20–23 Μm long, inner margins of lobes membranous. ALR 1.99–2.32. Male genital sac almost reaching apex of anal lobe.

4th instar larva (n = 1 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. 74A ). Length 490 Μm, 316 Μm wide. IC 0.65. 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 diagonal to longitudinal axis of head capsule ( Fig. 74A ).

Antenna ( Figs 74B–C ). Length 279 Μm, A1 189 Μm long, with ring organ located 0.84 from base, A2 79 Μm long. AR 2.11. Blade 87 Μm long, over-reached by accessory blade.

Maxilla ( Fig. 74D ). Basal palp segment 27 Μm long and 7 Μm wide at the middle, with ring organ located 0.83 from base. PR 3.42. APR 6.94.

Mandible ( Fig. 74E ). Length 72 Μm. Sensillum campaniformium located 0.68 from apex, basal tooth bifid, with seta subdentalis projecting from sloping end towards apical tooth, accessory tooth present, AMD 2.62.

Mentum and M appendage . Dorsomental teeth reduced; pseudoradula uniformly granulate, 80 Μm long.

Hypopharyngeal complex ( Figs 74F–G ). Ligula 62 Μm long, 59 Μm wide, with row of 5 teeth. IO 0.99, MO 1.07. Paraligula bifid, 28 Μm long, inner tooth 24 Μm long, shorter than outer tooth. Pecten hypopharyngis with 6 teeth almost equal in size.

Body ( Figs 74H–I ). Without lateral fringe. Anterior parapods with simple claws. Procercus 146 Μm long, 34 Μm wide, with 7 anal setae, 589 Μm long. L/ W 4.29. Supraanal seta well developed. Anal tubules not measurable. Posterior parapod 266 Μm long; subbasal seta on posterior parapod simple, without spines ( Fig. 74H ); parapod apex with numerous simple claws; bifid claw with V-shaped lower indentation ( Fig. 74I ). B/C 0.97.

Remarks. Adult males of Labrundinia separata appear most similar to those of L. carolae and L. sofiae , but can be separated by the completely brown abdominal tergite VI. The pupae of L. separata are quite similar to those of L. longipalpis and were fully discussed on the remarks of this species. The larvae of L. separata are very similar to those of L. sofiae , but can be distinguished by the entirely yellow head, without any maculation. Labrundinia separata is the only Labrundinia species with distribution exclusively in southern South America and has been recorded in Argentina and Chile.

Figures

FIGURES 72 A – M. Labrundinia separata (Edwards), 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 without comb. L. Abdominal coloration pattern, dorsal aspect. M. Hypopygium, left: ventral aspect, right: dorsal aspect.

FIGURES 73 A – F. Labrundinia separata (Edwards), 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 74 A – I. Labrundinia separata (Edwards), 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.