Endotribelos fulvidus, Trivinho-Strixino, Susana & Pepinelli, Mateus, 2015

Trivinho-Strixino, Susana & Pepinelli, Mateus, 2015, A systematic study on Endotribelos Grodhaus (Diptera: Chironomidae) from Brazil including DNA barcoding to link males and females, Zootaxa 3936 (1), pp. 1-41 : 11-14

Endotribelos fulvidus sp. n.

( Figs 5–8 )

Type material. Holotype: Male with pupal and larval exuviae, slide mounted in Euparal, Brazil, São Carlos, SP, Córrego Vintenove, iv.2012, S. Trivinho-Strixino (E3-39, LEIA-UFSCar); barcode (BNB2-00738). Paratypes: 2 male with pupal and larval exuviae as holotype except (E3-40 and E3-41, LEIA-UFSCar) and barcode (BNB2- 00734; BNB2-00746); 2 female with pupal and larval exuviae as holotype except (E3-42 and E3-43, LEIA- UFSCar) and barcode (BNB2-00744; BNB2-00741).

Etymology. The name fulvidus is given in allusion to the yellow and brown coloration the thorax and abdomen of the adults of this species.

Diagnostic characters. Endotribelos fulvidus sp. n. differs from all other species of the genus by the combination of the following characters. Adult male: thorax yellowish with small pairs of anterolateral brown spots and short brown triangular spot before the scutellum; postnotum brown; anal point thin, base as broad as apex and shorter than inferior volsella. Pupa: abdominal posterolateral spur simple; intersegmental membrane III/IV and IV/V with two patches of coarse shagreen. Larva: mentum with fourteen teeth; median teeth slightly shorter than first laterals; mandible with four inner teeth.

Male (n=2). Size. Total length 3.8–5.5 mm. Wing 2.2–2.5 mm long and 0.6–0.7 mm wide.

Coloration. Head yellowish; fourth and fifth palpomere and antenna brown. Thorax scutum yellowish with short pair of anterolateral brown spots and short brown triangular spot before the scutellum; postnotum brown ( Figs 5 a, b). Abdomen yellowish with brown bands as shown in figure 5c. Legs pale brown.

Head. Temporal setae 15. Clypeus with 30–40 setae. Antenna 1.38–1.51 mm long; AR 2.3–3.3. Palpomere 2–5 lengths: 50, 203–231, 130–150, 156–162 µm

Thorax. Ac 16–18; Dc 18–23; Pa 5–6; Scts 18–20 coarse and 7–10 finer setae on anterior face.

Wings. VR 1.10–1.15. Brachiolum with two setae. R with 27–40, R1 34–44 and R4+5 37 –45 setae, remaining veins bare. Squama with 9–11 setae.

Legs. Scale on fore tibia 46 µm long, with a short spine at apex ( Fig. 5 f). Tibial combs of mid and hind legs partly fused; mid tibial spur anterior short, 30 µm, posterior 70 µm long; hind tibial spur anterior 46 µm, posterior 77 µm long. Lengths and proportions as in Table 5 .

Hypopygium ( Fig. 5 d). Anal point 81–106 µm long; 9 µm wide medially; 18 µm near apex. Tergite IX with 16–19 strong setae. Laterosternite IX with two setae. Transverse sternapodeme 75 µm long. Phallapodeme 131µm long. Gonocoxite 178 µm long. Superior volsella 100 µm long, broad basally and strongly curved distally, with four long basal setae and one 74µm long sub-apical seta ( Fig. 5 e). Gonostylus 249 µm long. HR 0.71. HV 1.48–2.42.

Female (n=2). Dimension and coloration. Length 4.4–5.5 mm. Wing length 2.2–2.8 mm. Coloration as male except the brown markings of the posterolateral corner of scutum.

Head. Temporal setae 12. Clypeus with 45–47 setae. Antenna 0.66–0.81 mm long; AR 0.31–0.34. Palpomere 2–5 lengths: 44–51, 169–269, 156–175, 181–206 µm

Thorax. Ac 14–19; Dc 21–24; Pa 5; Scts 25–28 coarse and 5–6 finer setae anteriorly.

Wings. VR 1.12–1.16. Brachiolum with two setae. M with one, R 30–40, R1 60–80 and R4+5, 80–85 setae, remaining veins bare. Squama with 11–12 setae.

Legs. Scale on front tibia 34 µm long. Tibial combs of mid and hind legs partly fused; mid tibial spur 30 µm long; hind tibial spur anterior 38–46 µm, posterior 24–25 µm long. Lengths and proportions as in Table 6 .

Genitalia ( Fig. 6 ). Setal patches on sternite VIII with 29–30 setae. GC IX with 2–3 setae. Segment X with 10 setae. Seminal capsule 125 µm long. Notum 156 µm long, rami 78 µm. Gonocoxapodeme near 240 µm long. Cercus 122 µm long.

Pupa (n=4). Abdomen 4.0– 4.8 mm long. Wing sheath 1.6–1.7 mm long. Coloration pale brown.

Cephalothorax. Cephalic tubercles 63–78 µm long, conical, apically with several pointed spinules; frontal setae 171–181 µm long ( Fig. 7 a). Antepronotal seta 1, precorneal setae 2, dorsocentral setae 4. Distance between Dc1 and Dc 2 28–41 µm, between Dc2 and Dc3 218–318 µm, between Dc 3 and Dc 4 22–31 µm.

Abdomen. Tergite I bare, II–VI covered with shagreen, spines near central part of anterior margin stronger, VII and VIII bare. Paratergites III and VI with posterior patches of fine spines. Conjuntives III/IV and IV/V with two large patches of anteriorly directed large spines ( Figs 7 b, c). Hook row continuous with near 30 curved spines occupying near 1/3 width of segment II. Pedes spurii A and B present. Spur on segment VIII simple ( Fig. 7 d). Abdominal lateral setation: segment II–IV with three L setae, V–VI with three taeniate setae, VII–VIII with four taeniate setae. Anal lobes with 40–46 taeniate fringe setae on each side.

4th instar larva. Head capsule yellowish, tips of mandibles, mentum and occipital ring blackish.

Head. Dorsal head length 646–718 µm; width 477–500 µm; IC 0.69–0.74. Antennal basal segment 54–62 µm long. AR 1.08–1.19; antennal blade 48–51 µm long, shorter than antennal flagellum ( Fig. 8 c). Dorsal sclerites of head as in Figure 8 a, clypeus 44–62 µm long. Pecten epipharyngis formed by three toothed plates ( Fig. 8 b). Premandible with two major and one minor teeth; brush well developed. Mandible 191–234 µm long, with small dorsal tooth, apical and four inner teeth dark brown; seta subdentalis slender, 61 µm long ( Fig. 8 d). Mentum 200–234 µm wide, with fourteen dark brown teeth; median teeth slightly shorter than first laterals; 2nd lateral teeth smaller than the 3rd lateral teeth ( Fig. 8 e). Ventromental plates slightly shorter than mentum width, with very distinct striations; distance between ventramental plates 29 µm.

Figures

FIGURE 5. Endotribelos fulvidus sp. n. Male. a. Thorax, dorsal view. b. Thorax, lateral view. c. Abdmen dorsal view. d. Hypopygium, left dorsal view, right dorsal view, tergite IX removed and with detail of left superior volsella. e. Superior volsella. f. Fore tibial spine.

FIGURE 6. Endotribelos fulvidus sp. n. Female. a. Thorax, dorsal view. b. Genitalia ventral.

FIGURE 7. Endotribelos fulvidus sp. n. Pupa. a. Cephalic tubercle. b, c. Abdominal tergites with detail of spines of tergite II, hook and conjuntive II / IV. d. Posterolateral spur of abdominal segment VIII.

FIGURE 8. Endotribelos fulvidus sp. n. Larva. a. Dorsal sclerites of head. b. Pecten epipharyngis. c. Antenna. d. Mandible. e. Mentum and ventromental plate.

Tables

TABLE 5. Lengths (in Μm) and proportions of legs of Endotribelos fulvidus sp. n. male.

	fe	ti	ta1	ta2	ta3
p1	1446–1523	1077–1246	1354–1692	1138	861
p2	1338–1661	1153–1446	646–723	385–461	261–338
p3	1338–1646	1200–1477	923–1184	507–692	461–569

TABLE 6. Lengths (in Μm) and proportions of legs of Endotribelos fulvidus sp. n. male.

	ta4	ta5	LR	BR
p1	738	185	1.34–1.26	4.4
p2	169–185	76–92	0.50–0.57
p3	185–276	107–153	0.77–0.80