Labrundinia virescens Beck and Beck 1966
Creators: name: Silva, Fabio Laurindo Da
name: Fonseca-Gessner, Alaide Aparecida
name: Ekrem, Torbjørn
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Chironomidae
Labrundinia
Labrundinia virescens

description: Labrundinia virescens Beck and Beck, 1966
(Figs 86–88)
Labrundinia virescens Beck and Beck, 1966: 341 (description of adults and immatures); Roback 1971: 279 (description of male); Roback 1987: 197 (description of immatures).
Material examined. Type material: 1 male with pupal and larval exuviae, USA: Florida, Leon, Boliek's Pond, near Natural Bridge, 30.vi.1964, W. Beck (USNM 69124). 2 Paratypes: 1 female with pupal and larval exuviae same data as holotype except for 5.v.1964 (USNM 69124); 1 male with pupal and larval exuviae same data as holotype.
Additional material: 1 prepupa, USA: Florida, Leon, Boliek's Pond, 22.vii.1965, W. Beck; 1 larva as previous except for Flagler County, Rayonier Ditch, 18.vi.1964; 1 larva as previous except for Chaoborus Pond, 30.vi.1964; 1 larva, Florida, St. John's, Sphagnum Ditch, 17.xi.1965. 1 male with pupal and larval exuviae, Georgia, St. Simons Isl., Pond at Plantation village, Demere Rd. 23.xi.1990, B. A. Caldwell; 1 female as previous except for 28.xi.1990. 1 male, North Carolina, Belews Lake, 5.x.1976, S. S. Roback.
Diagnostic characters. Labrundinia virescens differs from other Labrundinia species by the combination of the following characters. Adult male: abdominal tergites I–II pale, T III–V with continuous brown transverse band near proximal margin, TVI–VIII almost completely brown; hypopygium pale, sternapodeme with moderate anterior process. Pupa: thoracic horn shaped like the number ‘9’, preapical indentation deep; segment II with dense multi-toothed spines; male genital sac extending somewhat beyond apex of anal lobe. Larva: surface of head capsule smooth; lateroventral spine group present, with 4–5 conspicuous spines; posteroventral spine group absent; mandible with short, subequal teeth.
Description. Adult male (n = 4)
Size. Total length 2.4–2.8 (3) mm. Wing length 1.3–1.6 mm. Total length/wing length 1.76–1.85 (3). Wing length/ profemur length 2.85–3.22.
Coloration. Head brown with dark brown occipital margin; pedicel and antenna brown; maxillary palp pale. Thorax pale brown with dark scutum; antepronotum pale; supraalar callus brown. Wing membrane transparent without any marking. Legs pale. Abdominal tergites I–II pale, T III–V with continuous brown transverse band near proximal margin, TVI–VIII almost completely brown; hypopygium pale (Fig. 86L).
Head (Figs 86A–E). Temporal setae 10 (2), uniserial (Fig. 86B). Eye ratio 0.78 (1). Tentorium (Fig. 86C) 130 (1) Μm long. Clypeus 95–110 (2) Μm long, 62–88 (2) Μm wide at largest part, bearing 14–17 (3) setae. Cibarial pump 127–276 (3) Μm long (Fig. 86D), with anterior margin concave. Lengths of palpomeres 1–5 (in Μm): 46 (1); 62 (1); 162 (1); 167 (1); 262 (1). Antennal flagellum 814–936 (2) Μm long, diameter of pedicel 65–98 (3) Μm, apical setae single (Fig. 86E), AR 1.47–1.50(2).
Thorax. Antepronotum with 4 (2) lateral setae. Acrostichals 32–54 (2), biserial, diverging evenly posteriorly, starting close to antepronotum and almost reaching scutellum; dorsocentrals 27–32 (2), irregularly biserial; prealars 9–12; supraalars 3. Anapleural suture ratio 0.41–0.42 (2). Scutellum with transverse row of 8 setae and group of numerous fine anterior setae.
Wing (Fig. 86F). Width 0.4 mm. Costa 1.1–1.3 mm long. R2+3 present. VR 0.74–0.79. WW 0.25–0.29. Brachiolum with 2 setae. Squama setiferous.
Legs (Figs 86G–K). Fore leg: width at apex of tibia 31–39 Μm (Fig. 86G), tibia with single, apical and pectinate spur 13–21 (10) Μm long (Fig. 86H), with three lateral teeth and two preapical setae; ta1-4 without any preapical pseudospurs. Mid leg: width at apex of tibia 31–43 Μm long (Fig. 86I), tibia with single, apical and pectinate spur 19–29 Μm long with 3–4 teeth (Fig. 86J) and two preapical setae; ta1-3 each with two preapical pseudospurs. Hind leg: width at apex of tibia 31–54 Μm long (Fig. 86K), tibia without spur; comb 7 setae; ta1 with two preapical pseudospurs. Claws slender, hooked; pulvilli absent. Lengths and proportion of leg segments as in Table 59.
fe ti ta1 ta2 ta3
p1 437–549 475–545 294–383 218–255 158–187 p2 465–712 443–589 466–714 287–332 159–175 p3 610 796 690 325 219
ta4 ta5 LR BV SV
p1 125–156 70–79 0.62–0.70 2.05–2.27 2.85–3.17 p2 107–126 87–98 1.05–1.21 2.15–2.75 1.82–1.95 p3 152 96 0.87 2.64 2.03 Hypopygium (Fig. 86M). Tergite IX arched, with 10–14 posterior setae. Membranous anal point trapezoidal, apical edge slightly notched. Phallapodeme 49–73 (3) Μm long. Sternapodeme with moderate anterior process. Gonocoxite cylindrical, 138–186 (3) Μm long, 43–82 (3) Μm wide, with slightly concave inner margin. GcR 2.27– 2.51 (3). Gonostylus simple and slender, 88–111 Μm long; megaseta 10–16 Μm long. HR 1.57–1.67 (3). HV 2.55– 3.97 (3).
Adult female (n = 2)
Size. Total length 1.7–1.9 mm. Wing length 1.2–1.3 mm. Total length/wing length 1.45–1.51. Wing length/ profemur length 2.56 (1).
Coloration. Head pale brown with dark brown occipital margin; pedicel and antenna brown; maxillary palp pale brown. Thorax brown dark scutum; antepronotum pale brown. Wing membrane transparent without any marking. Legs brown. Abdomen seems completely brown, not much distinguishable. Seminal capsules brown.
Head. Temporal setae 11 (1), uniserial. Eyes ratio 1.38 (1). Tentorium 160 (1) Μm long. Clypeus 84 (1) Μm long, 82 (1) Μm wide at largest part, bearing 22 setae. Cibarial pump 185 Μm long, as in male. Lengths of palpomeres 1–4 (in Μm): 52 (1); 53 (1); 110 (1); 114 (1); palpomeres 5 broken off. Antennal flagellum 416 (1) Μm long, diameter of pedicel 62 (1) Μm, AR 1.17 (1).
Thorax. Antepronotum setae not observed. Acrostichals 42–44, irregularly uniserial, starting close to antepronotum; dorsocentrals 36, irregularly biserial; prealars 10–11; supraalars 3. Scutellum with transverse row of 8 setae and group of numerous fine anterior setae.
Wing. Width 0.4–0.5 mm. Costa not measurable. R2+3 not observed. VR 0.82 (1). WW 0.30–0.43. Brachiolum with 2 setae. Squama setiferous.
Legs. Fore leg: width at apex of tibia 34–39 Μm, tibia with single, apical and pectinate spur 19–28 Μm, with three lateral teeth and two preapical setae; preapical pseudospurs on ta1-4 not observed. Mid leg: width at apex of tibia 46–47 Μm, tibia with single, apical and pectinate spur 23–38 Μm, with three lateral teeth and two preapical setae; preapical pseudospurs on ta1-4 not observed. Hind leg: width at apex of tibia 39–43 Μm long, tibia without spur; comb not observed; preapical pseudospurs on ta1-4 not observed. Claws slender, hooked; pulvilli absent. Lengths and proportion of leg segments as in Table 60.
Genitalia. Gonapophysis VIII broadly rounded, 68 (1) Μm long. Coxosternapodeme 87 (1) Μm long. Postgenital plate rounded. Cerci oval-quadrate, 68 (1) Μm long and 10 (1) Μm wide; with 4 (1) elongated setae. Labia with inconspicuous microtrichia. Notum length 107 (1) Μm long. Seminal capsules oval, 46 (1) Μm long, 36 (1) Μm wide, with conical shaped necks. Length ratio SCa/No 0.43(1).
Pupa (n = 4 unless otherwise stated)
Size. Abdomen 2.1–2.7 (3) mm long in male, 2.5(1) mm long in female.
Coloration. Exuviae mostly pale brown; thoracic horn brown.
fe ti ta1 ta2 ta3
p1 438 444 305 198 140 p2 632 578 625 234 156 p3 516 688 625 281 219
ta4 ta5 LR BV SV p1 108 80 0.68 2.26 2.88 p2 109 94 1.08 3.09 1.93 p3 140 86 0.91 2.51 1.91 Cephalothorax (Figs 87A–C). Frontal apotome smooth (Fig.87A). Wing sheath smooth 0.7–1.1 mm long. Thoracic horn 258–313 Μm long and 131–144 Μm wide (Fig. 87B), THR 1.94–2.17, preapical indentation deep. Membranous preapical papilla 50–54 Μm long (Fig. 87C), PTH 0.18–0.20, aeropyle tube simple, elongated and slender, 46–55 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 8–10 conical tubercles (Fig. 87B).
Abdomen (Figs 87D–F). Tergite I with scar 138–163 (2) Μm long. T I without shagreen, T II–VI with a few spines medial apical concentrated, T VII–VIII with shagreen medial concentrated. Segment II with dense multibranched spines (Fig. 87D). Abdominal chaetotaxy as in figure 87E. Abdominal segment VII with 4 LS-setae. A VIII with 5 LS-setae. Anal lobe 320–441 Μm long and 156–208 Μm wide (Fig. 87F), outer margins sclerotized, with 12–13 spines, longest spine 39–45 Μm long, inner margins of lobes membranous. ALR 1.99–2.11. Male genital sac extending somewhat beyond apex of anal lobe.
4th instar larva (n = 7 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. 88A). Length 668–683 (2) Μm, 382–426 (2) Μm wide. IC 0.55–0.64 (2).Surface smooth; lateroventral spine group present, with 4–5 spines; posteroventral spine group absent. Ventral cephalic setae S9, S10 and ventral pore (VP) forming a more or less right angle (Fig. 88A).
Antenna (Figs 88B–C). Length 338–390 Μm, A1 240–274 Μm long, with ring organ located 0.84–0.96 (5) from base, A2 86–100 Μm long. AR 2.35–2.55. Blade longer than A2 over-reached by accessory blade.
Maxilla (Fig. 88D). Basal palp segment 35–58 Μm long and 7–14 Μm wide at the middle, with ring organ located 0.73–0.85 (5) from base. PR 3.69–5.60. APR 4.30–7.32.
Mandible (Fig. 88E). Length 80–120 Μm. Sensillum campaniformium located 0.65–0.89 from apex, basal tooth bifid, with seta subdentalis projecting from sloping end towards apical tooth, accessory tooth present, AMD 2.02–3.11.
Mentum and M appendage. Dorsomental teeth reduced; pseudoradula uniformly granulate, 61–75 (2) Μm long.
Hypopharyngeal complex (Figs 88F–G). Ligula 70–89 (6) Μm long, 40–47 (6) Μm wide, with row of 5 teeth. IO 0.88–0.93, MO 0.98–1.06. Paraligula bifid, 31–40 Μm long, inner tooth 22–32 Μm long, shorter than outer tooth. Pecten hypopharyngis with 7 teeth almost equal in size.
Body (Figs 88H–I). Without lateral fringe. Anterior parapods with simple claws. Procercus 216–243 Μm long, 31–45 (6) Μm wide, with 7 anal setae, 412–739 (6) Μm long. L/ W 5.35 –8.76 (5). Supraanal seta well developed. Anal tubules 250–434 (5) Μm long. Posterior parapod 401 (1) Μm long; subbasal seta on posterior parapod simple, with 1–2 small spines basally (Fig. 88H); parapod apex with numerous simple claws; bifid claw with V-shaped lower indentation (Fig. 88I). B/C 1.22–1.29.
Remarks. Adult males of Labrundinia virescens are very similar to those of the related species L. opela and L. paravirescens, but may distinguished by having an abdominal tergite V which is brown in the anterior ¾. The pupae of L. virescens appear most similar to those of L. carolae and were fully discussed on the remarks of this species. The larvae of L. virescens are quite similar to those of L. jasoni and L. paravirescens, but can be separated by the large spines in the lateroventral spine group on the head. Labrundinia virescens is moderately abundant in the southeast of the United States. The larvae of this species were collected in lakes, creeks and unpolluted pools.
description: Published as part of Silva, Fabio Laurindo Da, Fonseca-Gessner, Alaide Aparecida & Ekrem, Torbjørn, 2014, A taxonomic revision of genus Labrundinia Fittkau, 1962 (Diptera: Chironomidae: Tanypodinae), pp. 1-185 in Zootaxa 3769 (1) on pages 177-179, DOI: 10.11646/zootaxa.3769.1.1, http://zenodo.org/record/250728