Pseudosmittia nana, 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 : 55-57

Pseudosmittia nana sp. n.

( Figs 148–153 )

Pseudosmittia sp. 3 Pinho et al. (2009: 164).

Type material. Holotype male, BRAZIL: Bahia State, Estação Ecológica Pau Brasil, Porto Seguro , 16º23'17.6''S, 39º10'55.6''W, 17.v. 2002, 107 m a.s.l., Malaise trap (Trilha 1), C.O. Azevedo et al. (BRPS20: BIOTA-FAPESP), ( MZUSP) . Paratypes: 2 males, São Paulo State, Parque Estadual Intervales, Ribeirão Grande, Barra Grande , 24º15'S, 48º10'W, 10–13.xii.2000, Malaise trap (Trilha 2), M.T. Tavares et al. (PEIN07: BIOTA-FAPESP) ( ZMBN) ; 1 male, as previous except 13–16.xii.2000, Malaise trap (Trilha 5), (PEIN09: BIOTA-FAPESP) ( MZUSP) .

Diagnostic characters. The species differs from other members of the genus by having scalpellate acrostichals and from other Neotropical species except P. windwardensis by the long costal extension.

Etymology. From Latin, nanus, dwarf, referring to the small size.

Male (n = 3–4, except when otherwise stated). Total length 0.98–1.30 mm. Wing length 0.55–0.79, 0.70 mm. Total length / wing length 1.71–1.83. Wing length / length of profemur 2.57–3.16.

Coloration. Thorax brown; abdomen with segments 3–5 pale, remaining segments brown; femora and basal half of tibiae brown, apical half of tibiae and tarsi pale brown.

Head. Antenna with twelve flagellomeres, AR 0.33 (1), ultimate flagellomere 90 (1) µm long or with thirteen flagellomeres, AR 0.32–0.36, ultimate flagellomere 126–139 µm long. Temporal setae 3–5, 4; consisting of 2–4, 3 inner verticals; 0–2, 1 outer verticals and 0–2, 1 postorbitals. Clypeus with 6–9, 7 setae. Tentorium, stipes and cibarial pump as in Figure 148 . Tentorium 49–81, 68 µm long; 9–11, 10 µm wide. Stipes 49 (1) µm long. Palpomere ( Fig. 149 ) lengths (in µm): 8–15, 11; 15–18, 16; 24–32, 28; 30–45, 41; 47–61, 55. Third palpomere with 3–4 lanceolate sensilla clavata, 7–11 µm long.

Thorax ( Fig. 150 ). Median antepronotal lobes strongly reduced; antepronotum with 0–1, 1 lateral seta. Dorsocentrals 4–5, 4; acrostichals 2, scalpellate; prealars 1–2, 1; supraalar absent. Scutellum with 2 setae.

Wing ( Fig. 151 ).Wing cuneiform. Cu 1 curved. R 4+5 ending proximal to apex of M 3+4. VR 1.23–1.82. Costal extension 30–93, 74 µm long. Brachiolum with 1 seta, other veins bare.

Legs. Spur of fore tibia 19–36, 27 µm long, spurs of mid tibia 9–11 µm and 8–9 µm long, of hind tibia 26– 34, 31 µm and 9–15, 11 µm long. Width at apex of fore tibia 17–19, 18 µm, of mid tibia 15–18 µm, of hind tibia 15–25, 21 µm. Comb with 7–12, 10 setae; longest 19–27, 24 µm long, shortest 13–16, 15 µm long. Length and proportions of legs as in Table 19.

Hypopygium ( Figs 152–153 ). Anal point 1–14 µm long. Tergite IX with 2 or 4 setae. Laterosternite IX with 2 setae. Phallapodeme 31–54, 46 µm long. Sternapodeme with oral projections indicated; transverse sternapodeme 31–36, 35 µm long. Virga triangular, 9 µm long. Gonocoxite 81–102, 93 µm long. Inferior volsella with 6–8 µm wide, 8–11 µm long, digitiform anterior lobe, projecting caudad; posterior lobe low, rounded. Gonostylus 38–44, 42 µm long, with low, rounded apical crista dorsalis; megaseta 3–6, 5 µm long. HR 2.13– 2.37, 2.22. HV 2.93–3.01.

Remarks. The presence of scalpellate acrostichals makes the placement in Pseudosmittia somewhat doubtful. However, in all other details the species resemble several other members of the genus.

Distribution and biology. The species was collected in Malaise traps in fragmented primary Mata Atlântica forests in São Paulo and Bahia States. In Bahia it was taken at about 100 m a.s.l., while in São Paulo above 800 m a.s.l.

Figures

FIGURES 148–153. Pseudosmittia nana sp. n., male. 148—tentorium, stipes, and cibarial pump; 149—palp; 150—thorax; 151—wing; 152—hypopygium, dorsal aspect; 153—hypopygium with anal point and tergite IX removed, dorsal aspect to the left, ventral aspect to the right.