Labrundinia parareniformis 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 : 109-115

Labrundinia parareniformis Silva sp. n.

( Figs 52–54 )

Labrundinia sp. 8 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, 08.vii.2008, F. L. Silva & J. F. Nunes ( MZUSP). 3 Paratypes: 1 female with pupal and larval exuviae same data as holotype ( NTNU); 1 male same data as holotype except for São Carlos, Valparaíso lake, 27.iv.2010, F. L. Silva ( NTNU). 1 pupa and larval exuviae same data as holotype ( NTNU).

Etymology. Derived from the Greek para, meaning near, and refers to the similarity of the new species to Labrundinia reniformis sp. n.

Diagnostic characters. Labrundinia parareniformis 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 completely brown; hypopygium pale brown, sternapodeme with anterior process absent, hypopygium ratio about 1.50. Pupa: thoracic horn kidney-shaped, preapical indentation reduced, thoracic horn about 2.17–2.20 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 = 2)

Size. Total length 1.8 (1) mm. Wing length 1.3 (1) mm. Total length/wing length 1.47 (1). Wing length/ profemur length 2.78 (1).

Coloration. Head brown with dark brown occipital margin; pedicel and antenna brown; maxillary palp pale. Thorax pale brown with dark scutum; supraalar callus 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 completely brown; hypopygium pale brown, sternapodeme with anterior process absent, hypopygium ratio about 1.50 ( Fig. 52L ).

Head ( Figs 52A–E ). Temporal setae 12–13, uniserial ( Fig. 52B ). Eye ratio 0.79 (1). Tentorium ( Fig. 52C ) 169 Μm long. Clypeus 81–90 Μm long, 54–56 Μm wide at largest part, bearing 11–13 setae. Cibarial pump 150–205 Μm long ( Fig. 52D ), with anterior margin concave. Lengths of palpomeres 1–5 (in Μm): 27–43; 45–56; 63–107; 88– 144, 225 (1). Antennal flagellum 703–725 Μm long, diameter of pedicel 121–147 Μm, apical setae single ( Fig. 52E ), AR 1.21–1.29.

Thorax. Antepronotum with 3–5 lateral setae. Acrostichals 42–46, biserial, diverging evenly posteriorly, starting close to antepronotum and almost reaching scutellum; dorsocentrals 20–22, irregularly uniserial; prealars 7–8; supraalars 2. Anapleural suture ratio 0.39. Scutellum with transverse row of 8–9 setae and group of numerous fine anterior setae.

Wing ( Fig. 52F ). Width 0.3 (1) mm. Costa 1.1 (1) mm long. R2+3 absent. VR 0.77 (1). WW 0.27 (1). Brachiolum with 2 setae. Squama setiferous.

Legs ( Figs 52G–K ). Fore leg: width at apex of tibia 35–40 Μm ( Fig. 52G ), tibia with single, apical and pectinate spur 14–18 Μm long ( Fig. 52H ), with three lateral teeth and two preapical setae; ta1-4 without any preapical pseudospurs. Mid leg: width at apex of tibia 38–40 Μm long ( Fig. 52I ), tibia with single, apical and pectinate spur 16–22 Μm long with three lateral teeth ( Fig. 52J ) and two preapical setae; ta1-4 each with two preapical pseudospurs. Hind leg: width at apex of tibia 38–39 Μm long ( Fig. 52K ), 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 35.

fe ti ta1 ta2 ta3

p1 423–449 502–503 370–418 241–249 165–192 p2 434–676 484–539 652–696 282–302 155–168 p3 538–573 636–703 674–706 284–287 177–205

ta4 ta5 LR BV SV

p1 123–131 82–91 0.74–0.83 2.02–2.16 2.22–2.57 p2 114–113 73–114 1.29–1.35 2.52–2.73 1.41–1.75 p3 125–123 78–79 1.00–1.06 2.79–2.85 1.74–1.81 Hypopygium ( Fig. 52M ). Tergite IX arched, with 9–10 posterior setae. Membranous anal point rounded, apical edge slightly convex. Phallapodeme 51–54 Μm long. Sternapodeme with anterior process absent. Gonocoxite cylindrical, 113 (1) Μm long, 51(2) Μm wide, with slightly concave inner margin. GcR 2.20 (1). Gonostylus simple and slender, 66–74 Μm long; megaseta 12–14 Μm long. HR 1.52 (1). HV 2.76 (1).

Adult female (n = 1)

Size. Total length 1.4 mm. Wing length 1.2 mm. Total length/wing length 1.66. Wing length/length of profemur 1.19.

Coloration. Head 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. Femur I brown, Fe II–III pale brown. Tibia I apex brown, Ti II–III pale brown. Tarsomere 1–5 brown to pale brown. Abdomen seems completely brown. Seminal capsules brown.

Head. Temporal setae 12, uniserial. Eyes ratio 1.08. Tentorium 166 Μm long. Clypeus 95 Μm long, 64 Μm wide at largest part, bearing 22 setae. Cibarial pump 220 Μm long, as in male. Lengths of palpomeres 1–4 (in Μm): 46; 62; 116; 143; palpomeres 5 broken off. Antennal flagellum 357 Μm long, diameter of pedicel 54 Μm, AR 0.37.

Thorax. Antepronotum with 3 lateral setae. Acrostichals 44, irregularly uniserial, starting close to antepronotum; dorsocentrals 30, irregularly biserial; prealars 10; supraalars 2. Scutellum with transverse row of 8 setae and group of numerous fine anterior setae.

Wing. Width 0.4 mm. Costa 1.0 mm long. R2+3 absent. VR 0.63. WW 0.37. Brachiolum with 2 setae. Squama setiferous.

Legs. Fore leg: width at apex of tibia 39 Μm, tibia with single, apical and pectinate spur 19 Μm, with three lateral teeth and two preapical setae; ta1-4 without any preapical pseudospurs. Mid leg: width at apex of tibia 43 Μm long, tibia with single, apical and pectinate spur 22 Μm long with three lateral teeth and two preapical setae; ta1-4 each with two preapical pseudospurs. Hind leg: width at apex of tibia 45 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 36.

fe ti ta1 ta2 ta3

p1 408 433 375 194 137 p2 549 467 578 244 153 p3 494 621 568 247 153

ta4 ta5 LR BV SV p1 106 75 0.86 2.38 2.25 p2 104 82 1.24 2.74 1.76 p3 108 77 0.92 2.88 1.96 Genitalia. Gonapophysis VIII broadly rounded, 59 Μm long. Coxosternapodeme 73 Μm long. Postgenital plate rounded. Cerci oval-quadrate, 38 Μm long and 12 Μm wide; with 5 elongated setae. Labia with inconspicuous microtrichia. Notum length 105 Μm long. Seminal capsules oval, 35 Μm long, 31 Μm wide, with conical shaped necks. Length ratio SCa/No 0.33.

Pupa (n = 3 unless otherwise stated)

Size. Abdomen 2.1 (1) mm long in male, 2.0–2.3 (2) mm long in female.

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

Cephalothorax ( Figs 53A–C ). Frontal apotome smooth ( Fig. 53A ). Wing sheath smooth 0.8 mm long. Thoracic horn 271–295 Μm long and 121–136 Μm wide ( Fig. 53B ), THR 2.17–2.24, preapical indentation moderately deep. Membranous preapical papilla 35–49 Μm long ( Fig. 53C ), PTH 0.11–0.18, aeropyle tube simple, short, 35–36 (2) 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 9–10 conical tubercles ( Fig. 53B ).

Abdomen ( Figs 53D–E ). Tergite I with scar 114–166. T I–VI without shagreen, T VII–VIII with shagreen basal concentrated. Abdominal chaetotaxy as in figure 53D. Abdominal segment VII with 4 LS-setae. A VIII with 5 LSsetae. Anal lobe 349–361 Μm long and 167–190 Μm wide ( Fig. 53E ), outer margins sclerotized, with 6–8 spines, longest spine 22–29 Μm long, inner margins of lobes membranous. ALR 1.83–2.14. Male genital sac not surpassing apex of anal lobe.

4th instar larva (n = 3 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. 54A ). Length 520–583 Μm, 314–325 Μm wide. IC 0.55–0.63Surface covered with small spinules; lateroventral spine group absent and posteroventral spine group present. Ventral cephalic setae S9, S10 and SSm forming a straight line diagonal to longitudinal axis of head capsule ( Fig. 54A ).

Antenna ( Figs 54B–C ). Length 293–296 Μm, A1 195–198 Μm long, with ring organ located 0.85–0.91 from base, A2 84–90 Μm long. AR 1.95–2.09. Blade longer than; accessory blade 91–102.

Maxilla ( Fig. 54D ). Basal palp segment 30–32 Μm long and 7–10 Μm wide at the middle, with ring organ located 0.83–0.86 from base. PR 3.09–4.16. APR 6.01–6.63.

Mandible ( Fig. 54E ). Length 73–84 Μm. Sensillum campaniformium located 0.65–0.78 from apex, basal tooth bifid, with seta subdentalis projecting from sloping end towards apical tooth, accessory tooth present, AMD 2.33– 2.71.

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

Hypopharyngeal complex ( Figs 54F–G ). Ligula 58–67 Μm long, 27–28 Μm wide, with row of 5 teeth. IO 0.98– 0.99, MO 1.04–1.10. Paraligula bifid, 27–33 Μm long, inner tooth 23–25 Μm long, shorter than outer tooth. Pecten hypopharyngis with 6 teeth almost equal in size.

Body ( Figs 54H–I ). Without lateral fringe. Anterior parapods with simple claws. Procercus 157–185 Μm long, 33–35 Μm wide, with 7 anal setae, 524–602 Μm long. L/ W 4.50 –5.44. Supraanal seta well developed. Anal tubules not measurable. Posterior parapod 469–534 Μm long; subbasal seta on posterior parapod simple ( Fig. 54H ); parapod apex with numerous simple claws and one serrated claw; bifid claw with V-shaped lower indentation ( Fig. 54I ). B/C 1.11–1.14 (2).

Remarks. Adult males of Labrundinia parareniformis very closely resemble those of L. reniformis and can be distinguished only by the hypopygium ratio, smaller in L. parareniformis . The pupae of L. parareniformis also appear most similar to those of L. reniformis , but can be distinguished from this species by the lateral indentation on the external margin of the thoracic horn forming a straight line perpendicular to longitudinal axis of the horn. This contrasts the lateral indentation on the external margin of the thoracic horn, which forms a straight line diagonal to the longitudinal axis of the horn in L. reniformis . The larvae of L. parareniformis are quite similar to those of L. reniformis , but can be distinguished by the presence of a posteroventral spine group on the head capsule. Labrundinia parareniformis and L. reniformis can also be separated by their COI gene sequences ( Silva et al. 2013). Labrundinia parareniformis has so far been recorded from two localities in São Paulo State, Brazil. The larvae were collected in reservoirs characterized by presence of aquatic macrophytes, Eichhornia azurea and Salvinia auriculata .

Figures

FIGURES 52 A – M. Labrundinia parareniformis 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 53 A – E. Labrundinia parareniformis 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 54 A – J. Labrundinia parareniformis 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.