Goeldichironomus adhaerens, Amora, Gizelle, Hamada, Neusa & Pinho, Luiz Carlos, 2015

Amora, Gizelle, Hamada, Neusa & Pinho, Luiz Carlos, 2015, New species and records of Goeldichironomus Fittkau, 1965 from Brazil (Diptera: Chironomidae), Zootaxa 4059 (2), pp. 383-392 : 384-390

Goeldichironomus adhaerens sp. n.

( Figures 1–6 )

Type material. Holotype male, BRAZIL: Amazonas, Manaus, Bairro Petrópolis, Instituto Nacional de Pesquisas da Amazônia, Laboratório de Ecofisiologia e Evolução Molecular, 3º06’50.17” S 59º58’30.99” W, 05.ii.2013, in phytoplankton tanks, leg. Morey, G. M. ( INPA). Paratypes: 2 males, 3 pupal exuviae, 3 larval exuviae, same data as holotype ( INPA).

Etymology. The name adhaerens (from latin, meaning “fused to each other”) refers to the fusion of gonocoxite and gonostylus.

Diagnostic characters. The new species can be distinguished from all other Goeldichironomus species by the combination of: Adult male —anal point narrow and gonocoxite and gonostylus fused. Larva —anterior pair of ventral anal tubules short and simple, labral sclerites 3 partially consolidated and pecten epipharyngis with unequal sized teeth and rounded apex teeth. Pupa —TII–III with posterior margin pigmented and arc-shaped pigmentation in the anterior margin of TII.

Description. Adult male (n =1–3). Total length 4.11–4.70 mm ( Figure 1 A).

Coloration: Head yellowish brown. Antennal flagellum dark brown. Maxillary palps yellowish brown. Wing with membrane transparent without spots, all veins yellowish brown. Thorax yellowish brown with brown mesonotal stripes and portions central dark brown. Scutellum yellowish brown. Sternum yellowish brown. Postnotum dark brown in posterior portion. Abdomen ligth brown, tergites without markings ( Fig. 2 E). Legs yellowish brown, with dark brown pigmentation on apex of forefemur, base of foretibia, apex of foretibia and tarsi, which are gradually darker towards apex in mid and hind tarsi.

Head ( Fig. 2 A). AR = 2.01–2.26. Apical flagellomere 836–938 µm long. Frontal tubercle absent. Maxilar palps with three sensilla clavate in distal region the third palpomere. Temporal with 17–20 setae. Dorsal and ventral interocular distance of 96–108 and 102–115, respectively. Clypeus with 14–21 setae. Lengths of palpomeres 1–5 (in Μm): 66–66; 40–45; 124–149; 124–149; 226–281.

Thorax ( Fig. 2 B). Tubercle well developed. Antepronotals 3–6 setae distributed in one rows. Acrostichals 8– 10. Dorsocentrals 7–8. Prealars 3–4. Supraalar 1 seta and scutellars 3–5.

Wing ( Fig. 2 C). 1.88–2.06 mm long, 0.54–0.56 mm wide. VR 0.87–1.19. WW: 0.21–0.29. Brachiolum with 3– 6 setae and 13–17 sensilla chaetica. R with 17–20, R1 with 15–21, R4+5 with 19–27 setae. Squama with 6–9 setae.

Legs ( Fig. 2 D). Mid and hind tarsomere 1 and 2 with 1–2 spur and 6–10 sensilla chaetica, respectively. Lengths (in Μm) and proportions of leg segments as in Table 1 .

Hypopygium ( Figs. 1 B-D and 3A–B). Lateroesternite IX with 4 setae. Anal tergite with 17 median setae and 22 setae inserted in the margin of tergite. Anal tergal bands V-type. Anal point 58–70 µm long, smooth and long. Phallapodeme 92–122 Μm, transverse sternapodeme 70–91 Μm long. Superior volsella 51–56 Μm, long, thin curved apex with folded ventrally. Inferior volsella 92–111 Μm long, not extending beyond mid-point of gonostylus with 19–22 setae. Gonocoxite 175–198 Μm long. Gonostylus 141–188 Μm long. Gonocoxite and gonostylus fused. HR 1.17–1.26. HV 4.40–4.57.

Pupa (n = 3). Abdomen length 3.98– 3.74 mm. Exuvia brownish.

Cephalothorax ( Fig. 4 G). Cephalic tubercles conical with frontal setae inserted subapically. Basal ring with fused branches.

Abdomen ( Fig. 5 A–D). Hook row continuous with 273–291 µm long, occupying 3/4 width of segment II. Pedes spurii B present on sternite II and Pedes spurii A present on sternite IV. Sternites bare. Tergite I without shagreen. Tergite II with shagreen evenly distributed, except in the posterolateral region. Tergite III–VI uniformly distributed, central-posterior region without shagreen. Tergites VII and VIII with two anterior patches of fine shagreen. Patches of small spines in the posterolateral corners of paratergites V–VII small and inconspicuous. Anal comb with four principal teeth and short teeth two or three acessory ( Figs. 4 A–F). Anal lobe with a fringe of about 86–99 taeniate setae each side. Abdominal chaetotaxy: segments I–IV with 0; 3; 3; 3 L setae; V–VIII 4; 4; 4; 5 lateral taeniate setae.

4th instar larva (n = 1–3). Total length 3.62–4.08 mm. Body red; head yellowish, without spot on gular region and on dorsal surface.

Head. Head capsule 237–281 Μm long, 407–455 Μm wide. IC 1.60–1.71. Labral sclerites 3 and 4 partially fragmented into larger granules ( Fig. 6 C). Pecten epipharyngis with 22 unequal sized teeth (6 taller than the 16 remaining), all with rounded apex ( Fig. 6 A). Premandible with 2 teeth yellowish brown, 43–68 Μm long. Antennal segment lengths: 43–46; 20–23; 14–15; 10–11; 4 µm; AR: 1.16. Basal segment 20–24 Μm wide, annular body near the base. Mandible 114–147 Μm long. Dorsal tooth yellowish brown; dark apical tooth and internal teeth. Mentum 112–134 ( Fig. 6 B) Μm wide; trifid median tooth and 6 pairs of lateral teeth, median tooth 35–39 Μm wide. Ventromental plates 149–177 Μm wide. Distance between ventromental plates smaller than the width of the middle tooth 9–13 Μm.

Abdomen. 8th segment with two pairs of short and simple ventral tubules, 218–256 Μm long ( Fig. 6 D). Anal tubules short and simple, 140–157 Μm long.

Distribution and bionomics. The tank where the egg mass of the new species was collected is located in a forested area inside INPA campus, at Manaus’ neighborhood. There are artificial lakes and ponds around the sampled place where may be the natural habitat of the species. Egg masses of G. holoprasinus and Chironomus sp. were also collected in the same tank.

Figures

FIGURE 1. Goeldichironomus adhaerens sp. n., male adult. A, Adult male, dorsal view. B, Hypopygium, dorsal view. C, Hypopygium, ventral view. D, Hypopygium, lateral view.

FIGURE 2. Goeldichironomus adhaerens sp. n., male adult. A, Head. B, Thorax. C, Wing. D, Legs. E, Abdomen.

FIGURE 3. Goeldichironomus adhaerens sp. n., male adult. A, Hypopygium, dorsal view. B, Hypopygium with anal point and tergite IX removed, dorsal aspect to the left and ventral aspect to the right.

FIGURE 4. Goeldichironomus adhaerens sp. n., pupa. A – F, Pupal anal comb variation. G—Pupal frontal apotome and cephalic tubercles.

FIGURE 5. Goeldichironomus adhaerens sp. n., pupa. A – D, Abdomen in dorsal view.

FIGURE 6. Goeldichironomus adhaerens sp. n., larva. A—Pecten epipharyngis. B—Mentum and ventromental plate. C— Frontal apotome and labral sclerites. D—Posterior abdominal segments.

Tables

TABLE 1. Lengths (in µm) and proportions of legs of Goeldichironomus adhaerens sp. n., male adult (n = 1 – 3).

Fe	Ti	ta1	ta2	ta3
p1 1026–1149	756–856	1165–1297	641–738	615–639
p2 889–999	796–869	493–516	254–263	192–195
p3 969–1071	1051–1176	734–770	250–401	302–338
ta4	ta5	LR	BV	SV
p1 600–628	217–233	1.51–1.64	1.46–1.47	1.45–1.54
p2 125–139	91–95	0.56–0.62	3.21–3.50	3.41–3.61
p3 183–188	95–103	2.90–3.35	2.74–2.92	2.93–4.04