Pseudosmittia larga, Mauad, Melina, Siri, Augusto & Donato, Mariano, 2013

Mauad, Melina, Siri, Augusto & Donato, Mariano, 2013, New species of Pseudosmittia Edwards, 1932 and new records of Allocladius Kieffer, 1913 (Diptera: Chironomidae, Orthocladiinae) from South America, Zootaxa 3694 (5), pp. 445-460 : 449-451

Pseudosmittia larga sp. n.

( Figs 5–8 )

Material examined. ARGENTINA: Holotype male, Buenos Aires, La Plata, Reserva Natural de Punta Lara, 38º 03' 36.5'' S, 62º 01' 18.4'' W, 29.xii.2011, sweep net, M. Donato and A. Siri; paratypes: 5 males same data as holotype.

Etymology. From Spanish larga = long; referring to the long median volsella.

Diagnosis. The combination of R4+5 ending proximal to M3+4; virga triangular consisting of a single spine without lateral spinules or additional structures; anal point 6–10 long covered by microtrichia; superior volsella and median volsella separated, superior volsella digitiform, median volsella longer than superior volsella; inferior volsella single with an apical triangular tip; distinguishes P. larga from all other species of the genus.

Male (n = 6, except when otherwise stated). Total length 1.6–1.8 (4) mm. Wing length 0.9–1.03 [0.9] mm. Total length/wing length 1.66–1.82 (4). Wing length/length of profemur 2.72–2.96 [2.73]. Coloration (specimens preserved in alcohol) uniformly dark brown with legs light brown.

Head. Antennae with 13 flagellomeres, AR 0.96–1.06 [1.00], ultimate flagellomere length 270–330 [280]. Temporal setae divided in 0–3 [3], inner verticals, 0–2 [0] outer verticals and 0–3 [1] postorbitals. Clypeus with 7– 9 [8] setae. Tentorium 98–115 [110] long and 15–17 [15] wide. Stipes 88–98 [90] long and 5–10 [5] wide. Palpomere lengths (1–5): 20–22 [20]; 27–37 [32]; 54–64 [54]; 64–68 [66]; 81–98 [85].

Thorax ( Fig. 5 ). Antepronotum with 1 lateral seta. Dorsocentrals 7–10 [9]; prealars 3–4 [4] (5); supraalars 1 (1). Scutellum with 2 [2] (5) setae.

Wing ( Fig. 6 ). VR 1.40–1.45 [1.4]. C extension 10–17 [13] (5). Brachiolum with 1 seta; other veins bare. Legs. Spur of front tibia 37–42 [37] (4) long; spurs of mid tibia 12–15 [12] (3) and 22 [22] (1); of hind tibia 15–20 [20] (5) and 39 [39] (2) long. Width at apex of front tibia 20–24 [20]; of midtibia 20–24 [20]; of hind tibia 29–34 [29]. Comb with 11–12 [11] setae. Lengths and proportions of legs in Table 2 .

Hypopygium ( Figs 7–8 ). Tergum IX with 6–10 [8] setae; laterosternite IX with 4–5 [4] setae. Anal point 6–10 (5) long. Phallapodeme 34–39 [34] long; transverse sternapodeme 68–76 [74] long. Virga 15–24 [17] long. Gonocoxite 124–134 [124] long; length from base of gonocoxite to apex of inferior volsella/ length of gonocoxite 0.24–0.29 [0.26]. Median volsella longer than superior volsella. Gonostylus 49–56 [49] long; megaseta 5–10 [10] long. HR 2.39–2.74 [2.53]; HV 3.18–3.67 (4).

Remarks. In the male identification key of Andersen et al. (2010), P. l a rg a keys in dilemma 21 but its character median volsella longer than superior volsella does not allow to continue in the key. The species P. magdae possesses a median volsella nearly as long as the superior volsella and the other option of this dilemma is median volsella shorter than superior volsella. When P. larga is keyed in the identification key of Ferrington & Saether (2011) the same as in P. saetheri occurs, since the inferior volsella of this species is different to that proposed by the authors. This species is very close to P. forcipata and may be a variation of this species. The key characters consist in the median volsella longer than superior volsella, inferior volsella without accessory lobe, anal point small, and Cu1 straigth.

Habitat. The species Pseudosmittia larga was collected in the protected area "Reserva natural Punta Lara" (RNPL), declared main area of the Biosphere Reserve "Pereyra Iraola" (UNESCO, Man and the Biosphere Programme, World Network of Biosphere Reserves (http://www.unesco.org/mab/). The RNPL contains wetlands such as marshes formed by the genera Scirpus , Schoenoplectus , Typha and Zizaniopsis , pounds and small lagoons. Besides, RNPL also protects the southernmost relict of the Paranean rain forest. This community has a similar specific composition like that of northeastern Argentina, eastern Paraguay and southwestern Brazil and reaches its southernmost distribution using the rivers Parana and Uruguay as biotic corridors. The climate is temperate and wet, between the years 1909 to 2005 the mean annual temperature was 16.2 C with 22.8 C in January and 9.9 C in July (Hurtado et al. 2006). The mean annual precipitations from the same period was 1040 mm (Hurtado op. cit.).

Figures

FIGURES 5 – 8. Pseudosmittia larga sp. n., male. 5, Thorax; 6, Wing; 7, Hypopygium with tergite IX removed, dorsal aspect to the right, ventral aspect to the left; 8, Hypopygium, dorsal aspect.

Tables

TABLE 2. Lengths (in µm) and proportions of legs of Pseudosmittia larga sp. n. (male) (n = 6). Measurements of the holotype in square brackets. For abbreviation explanations see Table 1.

fe	ti	ta1	ta2	ta3
P1 330–370 [330]	350–400 [350]	150–170 [160]	70–80 [80]	60 [60]
P2 390–460 [410]	370–430 [390]	180–200 [190]	90–100 [90]	70–80 [70]
P3 390–450 [410]	390–450 [400]	220–250 [220]	110–120 [110]	100–120 [110]
ta4	ta5	LR	BV	SV
P1 40 [40]	50 [50]	0.43–0.48 [0.46]	3.65–4.09 [3.65]	4.25–4.53 [4.25]
P2 40–50 [40]	40–50 [40]	0.44–0.49 [0.49]	3.62–4.16 [4.13]	4.21–4.69 [4.21]
P3 50–60 [50]	40–50 [50]	0.54–0.57 [0.55]	3.17–3.47 [3.22]	3.55–3.72 [3.68]