Nandeva digitifer, Andersen, Trond, Saether, Ole A. & Contreras-Ramos, Atilano, 2011

Andersen, Trond, Saether, Ole A. & Contreras-Ramos, Atilano, 2011, New species and records of Nandeva Wiedenbrug, Reiss et Fittkau (Chironomidae: Chironominae), Zootaxa 3136, pp. 45-60 : 50-53

Nandeva digitifer sp. n.

( Figs 3–16 )

Type material. Holotype male, CHILE: Region VII, Talca, El Golf, 24–27.xii.1995, at light, T. Andersen ( ZMBN Type No. 446). Paratypes: 43 males, 1 female, as holotype ( ZMBN).

Diagnostic characters. The apparent digitus together with the broadest extension of the superior volsella of any members of the genus will separate N. digitifer from other members of the genus. The species also is characterized by having 13–27 setae on M and an AR of 0.5–0.6. The female differs from N. latiloba by its larger size with a wing length of 1.13 mm compared to 0.82 mm and by having 35 setae on M compared to 6 setae in N. latiloba .

Etymology. From Latin, digitus, finger, and the suffix, - fer, carry, bear, referring to the presence of a digitus on the superior volsella.

Male (n = 10). Total length 1.88–2.17, 2.02 mm. Wing length 1.07–1.24, 1.17 mm. Total length / wing length 1.64–1.83, 1.74. Wing length / length of profemur 2.15–2.30, 2.21.

Color. Thorax with pale ground color and brown vittae, lower part of anterior anepisternum II, median anepisternum, anterior part of preepisternum and postnotum dark. Legs stramineous. Abdomen brownish with posterior one-third pale.

Head ( Fig. 3 ). AR 0.52–0.60, 0.56. Ultimate flagellomere 188–229, 217 μm long. Temporal setae 14–17, 15; including 7–12, 9 inner verticals; 2–5, 3 outer verticals; and 2–3, 3 postorbitals. Clypeus with 7–13, 11 setae. Tentorium, stipes and cibarial pump as in Fig. 4 . Tentorium 71–101, 93 μm long; 19–23, 22 μm wide. Stipes 79–120, 102 μm long; 19–26, 22 μm wide. Lengths (in μm) of palpomeres: 19–23, 20; 30–38, 34; 146–184, 168; 94–131, 117; 101–158, 142. Third palpomere with 2–3, 3 scalpellate sensilla clavata.

Thorax ( Fig. 5 ). Antepronotum with 3–5, 3 dorsal and 4–8, 6 lateral setae. Dorsocentrals 16–24, 20; acrostichals 13–19, 17; prealars 5–7, 6. Scutellum with 9–12, 11 setae.

Wing ( Fig. 6 ). VR 1.22–1.31, 1.27. Brachiolum with 2–3, 2 setae; Sc and An bare; R with 23–40, 31 setae; R1 with 15–28, 23; R4+5 with 36–52, 44; M with 13–27, 20; M1+2 with 32–60, 48; M3+4 with 33–50, 41; Cu with 34–53, 44; Cu1 with 13–32, 20; and postcubitus with 38–59, 50 setae. Cell m3+4 with about 120–200 setae; m basally of RM with 45–65, 54 setae. Squama with 2–3, 2 setae.

Legs. Scale on fore tibia with 23–26, 24 μm long apical point. Spurs of mid tibia 30–45, 36 μm and 19–30, 24 μm long including combs; of hind tibia 30–49, 39 μm and 23–34, 26 μm long including combs. Width at apex of fore tibia 30–38, 32 μm; of mid tibia 30–36, 33 μm; of hind tibia 34–38, 36 μm. Lengths and proportions of leg segments as in Table 1.

TABLE 1. Lengths (in µm) and proportions of legs of Nandeva digitifer sp. n., male (n = 10, except 9 for ta3–ta5 on fore- and hind legs).

fe ti ta1 ta2

p1 482–558, 526 444–529, 489 454–539, 501 255–293, 279 p2 501–567, 541 425–491, 456 293–350, 323 161–184, 170 p3 529–614, 570 576–680, 626 359–425, 389 203–246, 222

ta3 ta4 ta5 LR

p1 151–180, 167 85–104, 95 38–57, 46 1.00–1.08, 1.03 p2 113–142, 130 66–85, 76 38–47, 43 0.68–0.73, 0.71 p3 189–217, 203 109–132, 122 41–59, 53 0.60–0.64, 0.62

BV SV BR

p1 2.52–2.69, 2.58 1.96–2.12, 2.04 3.8–7.3, 4.6 p2 3.00–3.27, 3.16 2.99–3.22, 3.09 4.5–9.0, 6.4 p3 2.52–2.73, 2.65 3.02–3.15, 3.07 5.0–8.4, 6.9

Hypopygium ( Figs 7–9 ). Tergal band of curved V type, widely separated. Tergite IX with 14–20, 16 setae at base of anal point; laterosternite IX with 4–6, 5 setae. Anal point 47–69, 57 μm long; 7–9, 8 μm wide at base. Phallapodeme 57–76, 70 μm long. Transverse sternapodeme 19–36, 30 μm long; without oral projections. Gonocoxite 76–88, 82 μm long; gonostylus 97–114, 104 μm long. Superior volsella 33–57, 41 μm long, without microtrichia; base with 0–2, 1 short outer setae; extension 11–14, 12 μm wide, with 3 setae apically on inner margin and 0–2, 0 preapical setae; apparent digitus 9–19, 15 μm long, 5–9, 7 μm wide, with apical seta. Inferior volsella 64–73, 69 μm long; 14–16, 14 μm wide; with 14–16, 14 setae in apical third and long microtrichia. HR 0.72–0.83, 0.78; HV 1.82–2.09, 1.95.

Female (n = 1). Total length 1.72 mm. Wing length 1.13 mm. Total length / wing length 1.52. Wing length / length of profemur 2.45.

Color. As in male.

Head. AR 0.17. Length (in μm) of flagellomeres: 64, 64, 64, 56, 41. Sensilla chaeticae on flagellomeres 1 to 4 each 41 μm long. Temporal setae 14, including 9 inner verticals, 3 outer verticals, and 2 postorbitals. Clypeus with 16 setae. Tentorium, stipes, and cibarial pump as in Fig. 10 . Tentorium 86 μm long, 8 μm wide. Stipes 109 μm long, 34 μm wide. Lengths (in μm) of palpomeres: 23, 30, 143, 109, 131. Third palpomere with 3 scalpellate sensilla clavata.

Thorax ( Fig. 11 ). Antepronotum with 5 dorsal and 6 lateral setae. Dorsocentrals 20, acrostichals 16, prealars 5. Scutellum with 12 setae.

Wing ( Fig. 12 ). VR 1.27. Brachiolum with 3 setae, Sc bare, R with 34 setae, R1 with 26, R4+5 with 44, M with 35, M1+2 with 53, M3+4 with 55, Cu with 46, Cu1 with 20, An with 1 and postcubitus with 38–59, 50 setae. Cell m3+4 with about 200 setae, m basally of RM with 70 setae. Squama with 4 setae.

Legs. Scale on fore tibia with 30 μm long apical point. Spurs of mid tibia 38 μm and 23 μm long including combs, of hind tibia 41 μm and 26 μm long including combs. Width at apex of fore tibia 34 μm, of mid tibia 34 μm, of hind tibia 38 μm. Lengths and proportions of leg segments as in Table 2.

fe ti ta1 ta2 ta3 ta4 ta5 LR BV SV BR p1 463 444 – – – – – – – – – p2 510 425 284 137 104 66 43 0.67 3.49 3.30 5.6 p3 510 586 340 184 170 95 47 0.58 2.90 3.22 6.0 Abdomen. Setae both of tergites and sternites arranged in basal, marginal and lateral setae, with those on tergites more irregular and those of sternites more numerous medially. Number of setae on tergites I–VIII as: 13, 29, 35, 44, 50, 50, 28, 18; on sternites I–VIII as: 0, 7, 28, 52, 55, 53, 28, 66.

Genitalia ( Figs 13–16 ). Gonocoxapodemes VIII forming well sclerotized complete circles, each encircling about 33 setae. Floor developed. Dorsomesal lobe wider than the long and nearly straight ventrolateral lobe. Gonocoxite with 5 setae. Tergite IX somewhat bluntly triangular with 26 setae. Postgenital plate sharply triangular, narrow. Cercus 83 µm long. Seminal capsule about 65 µm long, about 55 µm wide, spermathecal ducts with long loop, without bulbs before common opening. Notum 107 µm long.

Remarks. Although the female not is associated through rearing the presence of setae on squama combined with RM continuous with R4+5 and R4+5 ending proximal to apex of M3+4 assures the placement in Nandeva . This new species could conceivably be a synonym of Nandeva chilena Wiedenbrug, Reiss et Fittkau described on the base of pupal exuviae from Southern Chile near Peulla ( Wiedenbrug et al. 1998: 65). However, the exuviae of N. chilena is considerably larger than the female adult of N. digitifer .

Distribution and biology. The species is known only from the type locality in Central Chile where it was collected at light in an area with gardens and farm lands irrigated from water channels.

Figures

FIGURES 3 – 9. Nandeva digitifer sp. n., male. 3 — head; 4 — tentorium, stipes and cibarial pump; 5 — thorax; 6 — wing; 7 — hypopygium, dorsal aspect; 8 — hypopygium with anal point and tergite IX removed, dorsal aspect to the left, ventral aspect to the right; 9 — superior volsella, dorsal view.

FIGURES 10 – 16. Nandeva digitifer sp. n., female. 10 — tentorium, stipes and cibarial pump; 11 — thorax; 12 — wing; 13 — genitalia, ventral aspect; 14 — genitalia, dorsal aspect; 15 — dorsomesal lobe; 16 — ventrolateral lobe.