Madachironomus rongaronga, Andersen, 2016

Andersen, Trond, 2016, MADACHIRONOMUS, A NEW GENUS OF TRIBE PSEUDOCHIRONOMINI (DIPTERA: CHIRONOMIDAE, CHIRONOMINAE) FROM MADAGASCAR Abstract, CHIRONOMUS Journal of Chironomidae Research 29 (29), pp. 15-26 : 23-24

Madachironomus rongaronga sp. n.

http://zoobank.org/ 378E3CFF-4AF5-408A-956A-0C99A71F295B

Type material. Holotype female, Madagascar, Toamasina province, Atsinanana region, Vohibinany district; Rianila drainage, Rongaronga River at Ambinaninony-Sahavalaina , approx. 49°07’E 18°34’S, evening of 19.ix.1995, light trap, leg. LRSAE / ORSTOM ( ZSM) . Paratypes: 3 females, same data as holotype ( ZMBN, ZSM) .

Etymology. Named after Rongaronga River , Toamasina province, Madagascar, where the species was collected. The name is to be regarded as a noun in apposition.

Diagnostic characters. See diagnostic characters for M. lakazana sp. n.

Description

Adult female (n = 4). Total length 7.07–7.83, 7.49 mm. Wing length 3.11–3.58, 3.28 mm. Total length / wing length 2.08–2.45, 2.26. Wing length / length of profemur 2.22–2.43, 2.35.

Coloration. Head, antennae and palpi brown. Thorax mostly brown, without lateral mesonotal dark spot. Legs brown; foreleg with lighter brown ta 1; mid- and hind legs with lighter brown tarsi. Wing membrane ( Fig. 9 ) translucent with brownish stain and more darkly shaded areas, e.g. proximally and distally in cell c, along most of sc, proximally in r 1 and r 4+5, along Cu and proximal parts of M 3+4 and Cu 1; veins brown, crossvein RM and radial fork darker brown. Abdomen and hypopygium brown, first abdominal segment lighter brown.

Antenna. With 6 flagellomeres; AR = 0.70–0.81, 0.78. Length and width of pedicel and flagellomeres 1–6 (in µm) as: 72–84, 80 / 112–120, 117; 80– 88, 85 / 44–48, 46; 60–64, 61 / 34–40, 36; 68–80, 72 / 32–40, 36; 64–76, 71 / 32–38, 36; 64–80, 74 / 32–36, 34; 276–296, 288 / 24–30, 28. Flagellomeres 1–5 with ring of sensilla chaetica subapically, flagellomere 6 with sensilla chaetica in apical 3/4. Flagellomere 6 with 1–2 strong setae subapically, longest 121–160, 138 µm long.

Head. Temporal setae 14–18, 16, briefly bi-serial near transition of eye to its dorsomedial extension, consisting of inseparably intergrading verticals and postorbitals. Clypeus with 79–108, 93 setae. Tentorium 180–256, 220 µm long; 56–64, 61 µm wide. Stipes 220–240, 230 µm long; 18–23, 21 µm wide. Palp segment lengths (in µm): 80–88, 85; 92–112, 99; 332–420, 362; 356–436, 389; 560–648, 590. Third palpomere with 1–2 sensilla clavata apically, longest 17–22 µm long.

Thorax. Antepronotum with 4–7, 5 dorsal and 7–12, 10 ventrolateral setae. Acrostichals apparently about 35; dorsocentrals 24–34, 30 weak, in 1–2 irregular rows; prealars 4–6, 5. Scutellum with 41–44, 42 setae in 2–3 rows.

Wing ( Fig. 9 ). VR 0.94–1.00, 0.97. C extension 47–75, 65 µm long. Brachiolum with 2–3, 2 setae; C extension with 2–4, 3 non-marginal setae; R 1 with 5–14, 11 setae in apical 1/3; R 4+5 with 1–3, 2 setae apically; other veins bare. Wing membrane bare. Squama with 27–33, 31 setae, partly bi- to tri-serial.

Legs. Spur of fore tibia 60–64, 62 µm long; spurs of mid tibia 68–84 (3) µm and 80–100, 94 µm long; of hind tibia 80–96, 90 µm and 96–108, 103 µm long. Width at apex of fore tibia 96–100, 99 µm; of mid tibia 100–108, 104 µm; of hind tibia 104–116, 113 µm. Mid ta 1 with about 35 sensilla chaetica in 2–3 rows in proximal 1/3, hind ta 1 with about 40 sensilla chaetica in 2–3 rows in proximal 1/3. Lengths and proportions of legs as in Table 3 .

Genitalia ( Figs 20–25 ). Segment X with 53–78, 63 setae to each side of vagina. Tergite IX with 22– 28, 24 setae. Seminal capsule ovoid, 133 (1) μm long, not including 31 (1) μm long neck, 121 (1) μm wide. Notum 184–193 (3) μm long. Dorsomesal lobe 156–176, 165 μm long from base of vagina to apex. Gonocoxite IX with 16–23, 18 setae. Tergite IX with 21–27, 24 setae. Cercus 208–240, 225 μm long.

Adult male, larva and pupa. Unknown.

Figures

Figures 8-9. Madachironomus gen. n., wings. 8) M. lakazana sp. n., male; 9) M. rongaronga sp. n., female (photo Torbjørn Ekrem).

Figures 20-25. Madachironomus rongaronga gen. n., sp. n., female. 20) genitalia, ventral view; 21) tergite IX; 22) dorsomesal lobe; 23) ventrolateral lobe; 24) apodeme lobe; 25) labium.

Tables

Table 3. Lengths (in µm) and proportions of legs of Madachironomus rongaronga gen. n., sp. n., female (n = 3, except when otherwise stated).

	fe	ti	ta1	ta2	ta3	ta4
p 1 p 2 p 3	1318–1524 1751–2019 1895–2163 ta 5	1772–2081 2225–2534 2431–2699 LR	1318–1483 803–927 1009–1154	618–701 433–494 536–618 BV	536–577 350–391 433–474 SV	433–474 206–247 247–288 BR
p 1 p 2 p 3	196–227 103–124 103–124	0.970–1.000 2.446–2.573 0.358–0.366 4.315–4.434 0.415–0.427 3.912–4.047			2.344–2.453 4.911–5.026 4.214–4.286	1.471 (1) 1.643 (1) 2.125–2.500