Allocladius bilobulatus (Edwards) Andersen & Saether & Mendes, 2010

Andersen, Trond, Saether, Ole A. & Mendes, Humberto F., 2010, Neotropical Allocladius Kieffer, 1913 and Pseudosmittia Edwards, 1932 (Diptera: Chironomidae) 2472, Zootaxa 2472 (1), pp. 1-77 : 6-10

Allocladius bilobulatus (Edwards) comb. n.

( Figs 1–16 )

Smittia (Smittia) bilobulata Edwards, 1931: 299 .

Pseudosmittia bilobulata (Edwards) ; Paggi (1993: 172), Pinho et al. (2009: 164).

Material examined. ARGENTINA: Territorio Río Negro, Viedma , male holotype, 23.x.1926, F.W. & M. Edwards (BM 1927–63, BMNH) . CHILE: Región Metropolitana, San José de Maipo, Puente Río Yeso , 33º47.127'S, 70º13.625'W, 1.842 m a.s.l., 2 males, 25.i.1996, hand net, T. Andersen; as previous except 8 males, 16.ii.1999; San José de Maipo, Río Yeso , 8 km East of Romeral , 1 male, 31.i.2009, hand net, T. Andersen ; Santiago, Calera de Tango , El Copihue, 520 m a.s.l., 6 males, 01.ii.2009, hand net, T. Andersen ( ZMBN) . PERU: Cusco Region, Urubamba Province, Aguas Calientes , 1.900 m a.s.l., 19 males, 1 female, 22.i.2009, hand net, T. Andersen ( ZMBN) .

Diagnostic characters. The presence of a short (18–36 µm long) single pars ventralis together with a thumbnail-like virga will separate the species from other species of the longicrus group.

Male (n = 9–11, except when otherwise stated). Total length 1.72–2.11, 2.00 mm. Wing length 1.08–1.29, 1.21 mm. Total length / wing length 1.58–1.81, 1.67. Wing length / length of profemur 2.81–3.04, 2.97.

Coloration. Brown.

Head. AR 0.64–0.84, 0.71. Ultimate flagellomere 223–328, 322 µm long. Temporal setae 5–9, 7; consisting of 1–3, 2 inner verticals; 0–3, 1 outer verticals and 1–4, 3 postorbital. Clypeus with 8–16, 11 setae. Tentorium, stipes, and cibarial pump as in Figure 1 . Tentorium 97–128, 113 µm long; 20–34, 26 µm wide. Stipes 118–143, 134 µm long; 23–59, 44 µm wide. Palpomere ( Fig. 2 ) lengths (in µm): 16–30, 23; 29–45, 39; 66–91, 80; 79–98, 85; 100–138, 118. Third palpomere with 1 sensilla clavata; 9–16, 12 µm long.

Thorax ( Fig. 3 ). Median antepronotal lobes comparatively well developed; antepronotum with 1–4, 2 weak lateral setae. Dorsocentrals 7–9, 8; acrostichals 5–11, 7 (8), strong; prealars 3–6, 4 with 0–2, 1 anteriorly; supraalar 0–1, 1. Scutellum with 4–8, 6 setae.

Wing ( Fig. 4 ). VR 1.32–1.41, 1.37. Anal lobe reduced. Costal extension 0–23, 6 µm long. R 4+5 ending slightly proximal to apex of M 3+4; Cu 1 curved. Brachiolum with 1 seta; R with 0–3, 1 setae; other veins bare.

Legs. Spur of fore tibia 32–41, 36 µm long; spurs of mid tibia 16–23, 20 µm and 11–20, 15 µm long; of hind tibia 23–48, 41 µm and 11–16, 15 µm long. Width at apex of fore tibia 20–27, 25 µm; of mid tibia 23–27, 25 µm; of hind tibia 26–41, 34 µm. Comb with 12–14, 13 setae; longest 27–34, 31 µm long; shortest 16–25, 19 µm long. Length (in µm) and proportions of legs as in Table 1.

Hypopygium ( Figs 5–6 ). Anal point 9–26, 15 µm long, with 4–11, 7 setae at base; tergite IX with 5–17, 10 minute additional setae. Laterosternite IX with 5–8, 6 setae. Phallapodeme 54–73, 61 µm long. Transverse sternapodeme 48–66, 58 µm long, with weak oral projections. Virga 7–14, 9 µm long, thumbnail-like. Pars ventralis ( Fig. 7 ) single, 18–36, 29 µm long; 7–11, 9 µm wide at apex. Gonocoxite 132–173, 150 µm long. Superior volsella present as dorsal swelling of inner margin of gonocoxite, reaching to 0.46 gonocoxite length. Inferior volsella and posterior lobe well developed, reaching to 0.59 and 0.76 gonocoxite length, respectively. Gonostylus 52–64, 59 µm long; megaseta 6–12, 8 µm long. HR 2.32–2.78, 2.53. HV 3.12–3.91, 3.38.

Female (n = 1). Total length 1.79 mm. Wing length 1.04 mm. Total length / wing length 1.71. Wing length / length of profemur 3.25.

Coloration. Brown.

Head. AR 0.35. Lengths / width (in µm) of flagellomeres: 52/20, 39/20, 35/19, 36/18, 59/17. Temporal setae 9, including 5–6 inner verticals and 3–4 outer verticals. Clypeus with 7 setae. Tentorium, stipes, and cibarial pump as in Figure 8 . Tentorium 91 µm long, 18 µm wide. Stipes 111 µm long, 39 µm wide. Palpomere ( Fig. 9 ) lengths (in µm): 20, 27, 57, 68, 98. Third palpomere with 2 sensilla clavata, longest 11 µm long. Coronal suture 41 µm long.

Thorax ( Fig. 10 ). Median antepronotal lobes well developed, antepronotum with 1 lateral seta. Dorsocentrals 10, acrostichals 6, prealars 4, supraalar 1. Scutellum with 6 setae.

Wing ( Fig. 11 ). VR 1.43. Anal lobe well developed. Costal extension 41 µm long. R 4+5 ending above apex of M 3+4, Cu 1 slightly sinuate. Brachiolum with 1 setae, costa between FR and apex of R 4+5 with 26 non-marginal setae, costal extension with 3 non-marginal setae, R with 6, R 1 with 4, R 4+5 with 13 setae, other veins bare.

Legs. Spur of fore tibia 23 µm long, spurs of mid tibia 16 µm and 14 µm long, of hind tibia 32 µm and 11 µm long. Width at apex of fore tibia 23 µm, of mid tibia 23 µm, of hind tibia 27 µm. Comb of 13 setae, shortest 16 µm long, longest 25 µm long. Length and proportions of legs as in Table 2.

Abdomen. Tergites I–VIII with 10, 11, 18, 20, 21, 25, 23 and 21 setae, respectively. Sternite I bare, S II– VIII with 7, 6, 10, 10 14, 15 and 28 setae, respectively.

Genitalia ( Figs 12–15 ). Gonocoxite low, without posterior projection, with 9 moderately strong setae. Tergite IX apparently undivided, with altogether about 20 setae. Cercus 59 µm long. Segment X with broadly triangular, rounded posterolateral corners. Seminal capsule 36 µm long, 36 µm wide, including 11 µm long neck, neck 3 µm wide at apex, microtrichia not observed, spermathecal ducts with loop, apparently without bulbs and with common opening. Notum 91 µm long.

Pupa and larva. Unknown.

Remarks. The single female is not in a good position on the slide. It may be that tergite IX is more divided into setigerous protrusions and that the posterolateral corners of segment X are more pointed than shown in the drawing.

Distribution and biology. The species is known from Argentina, Chile and Peru. In Peru it was swarming in the afternoon close to the ground along the banks of a fast flowing river at 1.900 m a.s.l. In central Chile it was netted along the banks of a rather fast flowing river at 1.850 –1.900 m a.s.l. and taken swarming in late afternoon above 1.5–2.0 m high plants in a garden at about 500 m a.s.l.

Figures

FIGURES 1–7. Allocladius bilobulatus (Edwards, 1931) comb. n., male. 1—tentorium, stipes, and cibarial pump; 2— palp; 3—thorax; 4—wing; 5—hypopygium, dorsal aspect; 6—hypopygium with anal point and tergite IX removed, dorsal aspect to the left, ventral aspect to the right; 7—pars ventralis.

FIGURES 8–16. Allocladius bilobulatus (Edwards, 1931) comb. n., female. 8—tentorium, stipes, and cibarial pump; 9—palp; 10—thorax; 11—wing; 12—genitalia, ventral aspect; 13—genitalia, dorsal aspect; 14—ventrolateral lobe; 15—dorsomesal lobe; 16—apodeme lobe.