Corynoneura unicapsulata, Wiedenbrug, Sofia & Trivinho-Strixino, Susana, 2011

Wiedenbrug, Sofia & Trivinho-Strixino, Susana, 2011, New species of the genus Corynoneura Winnertz (Diptera, Chironomidae) from Brazil, Zootaxa 2822, pp. 1-40 : 30-36

Corynoneura unicapsulata sp. n.

( Figs 19–21 )

Corynoneura -Gruppe spec. 3: Wiedenbrug 2000: 100

Type material. Holotype male with pupal and larval exuviae, BRAZIL, SP, São Paulo, Parque Estadual do Jaraguá, stream near playground, 9.ix.2007, S. Wiedenbrug. Paratypes: allotype female with pupal and larval exuviae same data as holotype; 5 males and 3 females all with pupal and larval exuviae, same data as holotype; one pharate male with pupal exuviae, SP, Jundiaí, Serra do Japí, 23°14´30´´S, 46° 57´16´´W, 18.xii.2007, S. Wiedenbrug; two males (one of them UFSCAR MPSW 046), one pharate male (UFSCAR MPSW 039), one female, all with pupal and larval exuviae, two pharate male with pupal exuviae and one pupa with larval exuviae (UFSCAR Diagnostic characters. The adult males are separable from other species by the antenna with 9–10 flagellomeres, AR 0.4–0.6, apical flagellomere composed of two or three fused flagellomeres. Eyes bare, attachment of the phallapodeme caudal on the lateral sternapodeme, phallapodeme posterior margin sclerotized and strongly curved to anterior, small superior volsella bearing long seta and the gonostylus with prominent crista dorsalis. Adult females are separable from other species by the labia funnel shaped as C. septadentata , one large seminal capsule sclerotized about 47 µm and the second apparently absent, gonapophysis margin medially lobed. The pupae are distinguished from other species by the absence of pearl row on the wing sheath, the spines of shagreen on tergites IV and V increasing posteriorly in size, posterior spines as long as wide, 3 short lateral setae on segments III–VIII, anal lobe rectangular, anal lobe lateral margin without setae and posterior margin with fringe. The larvae can be recognized by the head integument without sculptures, the mentum with 3 median and 6 lateral teeth, antenna longer than post mentum, AR 0.9–1.1, Frontal apotome about 180–195 µm long, modified abdominal setae wider but not apically split, basal seta on posterior parapods with one pectinate side.

Etymology. From Latin unum meaning one, referring to the presence of only one visible seminal capsule on the female.

Description. Male (n = 1–3)

Total length [0.88]– 1.02 mm. Wing length [0.59]– 0.61 mm. Total length/wing length [1.51]. Wing length/ length of profemur 3.28–[3.45].

Color. Thorax brownish; legs whitish; tergites I whitish, II–IX brownish.

Head. AR = [0.38]–0.63. Antenna with [9]–10 flagellomeres, ultimate flagellomere [95]–145 µm long, composed of two or three fused flagellomeres; one sensilla chaetica at the second and third and two at the last flagellomere. Flagellomeres with more than one row of setae each ( Fig. 19 A). Temporal setae absent. Clypeus 30–[45] µm long, with 8 setae. Tentorium 102–107 µm long, 10–12 µm wide. Palpomere lengths (in µm): [7]–10, 10–[12], 12–[15], 15–20 [17], [45]. Third palpomere with one sensilla clavata. Eyes pubescent.

Thorax ( Fig. 19 B). Antepronotum with 1 lateral seta. Dorsocentrals 3, prealars 2. Scutellars 2. Antepronotal lobes dorsally reduced, tapering.

Wing ( Fig. 19 C). VR 3.30–[3.41]. Clavus 25–[30] µm wide, ending 127– [135] µm from arculus. Clavus/wing length 0.21–[0.23]. Anal lobe absent.

Legs. Spur of front tibia [20] 17–22 µm long; spur of middle tibia [10] µm long; spurs of hind tibia [30]–42 µm long, second spur s-shaped. Width of apex of front tibia [15]–20 µm, of middle tibia 12–[15] µm, of hind tibia 30– [37] µm. Hind tibial scale [32] 30–35 µm long ( Fig. 19 D). Leg measurements (in µm) and ratios as in Table 13.

fe ti ta1 ta2 ta3 ta4 ta5 LR BV SV BR p1 147–185 225–245 97–100 57–65 32–35 15–17 22–25 0.41–0.43 3.72–3.79 3.97–4.30 1.75–2.00 p2 225–250 225–243 140–157 57–68 30–33 15 22–25 0.62–0.66 4.67–4.73 3.05–3.25 3.00–3.66 p3 175–190 212–215 115–122 65–70 27–30 15 22–25 0.53–0.58 3.71–3.97 3.24–3.39 2.50–2.75

Abdomen. Without seta.

Hypopygium ( Figs 19 E–G) Tergite IX with 2 setae. Laterosternite IX with 1 seta. Superior volsella small, rounded with long setae medially directed. Inferior volsella prominent with longer microtrichia medially directed. Phallapodeme strongly curved to anterior, sclerotized on posterior margin, 17–22 µm long; transverse sternapodeme 17–[20] µm long. Gonocoxite [60]–65 µm long. Gonostylus with a strong crista dorsalis [17] µm long; megaseta [10] µm long. HR [3.42]–3.71; HV [5.06].

Female (n = 2)

Thorax 0.36 mm (n = 1). Abdomen 0.71 mm length (n = 1). Wing length 0.58–0.68 mm. Wing length/ profemur 3.54–3.98.

Color. Thorax brownish; legs whitish; tergite I whitish, II–IX brownish.

Head. AR 0.44–0.48. Antenna with 5 flagellomeres, apical flagellomere 57 µm long; one sensilla chaetica on flagellomeres 2–4 and two on flagellomeres 5. Temporal setae absent. Clypeus 35–42 µm long, with 6–8 setae. Tentorium 45–75 µm long, 5 µm wide. Palpomere lengths (in µm): 10–12, 12, 15–17, 17–20, 45–47. One sensilla clavata on third palpomere. Eyes pubescent.

Thorax. Antepronotals 1, dorsocentrals 3, prealars 2. Scutellars not possible to see. Antepronotal lobes dorsally tapering.

Wing ( Fig. 20 A). VR 2.17–2.26. Clavus 17–27 µm wide, ending 192–235 µm from arculus. Clavus/wing length 0.33–0.34.

Legs. Spur of front tibia 7–12 µm long; spur of middle tibia 12 µm long; spurs of hind tibia 37–40 µm long, second spur small s-shaped. Hind tibial scale 35–45 µm long. Width of apex of front tibia 15 µm, of middle tibia 12–15 µm, of hind tibia 25–35 µm. Leg measurements (in µm) and ratios as in Table 14 .

fe ti ta1 ta2 ta3 ta4 ta5 LR BV SV BR Abdomen. Setae on abdomen absent.

Genitalia ( Figs 20 B–D). Gonocoxite IX with 1 seta. Tergite IX with 4 setae. Seminal capsule 47 µm, second seminal capsule apparently absent, both seminal ducts with a loop joined together shortly before seminal eminence, which has sclerotized outer borders. Notum 30–35 µm long, membrane median well sclerotized. Apodeme lobe anterior margin in the same shape as membrane, apically pointed. Coxosternapodeme strongly curved with welldeveloped lateral lamellae, coxosternapodeme with one end stronger sclerotized at the roof of copulatory bursa, which is semicircle-shaped. Labia membranous, bare, separated, triangle-shaped, ventrally longer than copulatory bursa posterior margin, apically funnel shaped, median apical margin with small curves building the accessory gonopore(?), labia dorsally with straight median margin, building the funnel posterior to the posterior margin of the copulatory burse. Gonocoxapodeme straight, gonapophyses strongly lobed medially. Post-genital plate quadrangular, with microtrichia. Cercus 35 – 42 µm long.

Pupa (n = 1–3)

Total length 1.24–1.29 mm.

Cephalothorax. Frontal apotome with few granulation ( Fig. 20 A). Frontal setae 40–112 µm long. Postorbitals 20–42 µm and 25–42 µm. Median antepronotals 25–45 µm. Lateral antepronotals 17–35 µm. Pc2 37 µm. Dorsocentrals Dc 1 22–27 µm long; Dc 2 15–27 µm long; Dc3 20 µm long; Dc4 15 µm long. Distance between Dc1 and Dc2 75–90 µm; Dc2 and Dc3 45–52 µm; Dc3 and Dc 4 20–22 µm. Dc1 displaced ventrally. Wing sheaths without row of pearls ( Fig. 20 B).

Abdomen ( Figs 20 C–F). Tergite I and sternite I–II without shagreen. Tergite II with few shagreen points. Tergites III–VIII with fine shagreen grading to a row of stronger points posteriorly (Figs E–F). Tergite IX with fine shagreen. Sternites III–IV, VIII with fine shagreen posteriorly, V–VII with fine shagreen. Sternite VIII on female bare. Conjunctive TII/III with 4–11 hooklets; TIII/IV with 12–21 hooklets; TIV/V with 13–21 hooklets; TV/VI with 12– 19 spinules; TVI/VII with 25–32 spinules; TVII–VIII with a row of 30 small spinules; SIV/V with 9–12 spinules; SV/VI with 12–13 hooklets; SVI/VII with 9–12 hooklets, SVII/VIII with 6–11 hooklets. Segment I with 3 D-setae, 1 L-setae, without V-setae; segments II–III 3 D, 3 V and 3 L-setae; segments IV–VII with 4 D, 3V and 3 very thin and short taeniate L-setae; segment VIII with 2 D, 1 V and 3 very thin and short taeniate L-setae.

Anal lobe rectangular 105 µm long. Anal lobe fringe without lateral setae, posterior with 13–15 taeniate setae 250–325 µm long; 3 macrosetae thin and taeniate, 20–42 µm long; inner setae taeniate 50 µm long.

Larva (n = 1–3)

Head. Head capsule integument smooth. Frontal apotome 182–192 µm long; head width 147–165 µm; postmentum 140–147 µm long; postmentum/head width 0.89–0.95. SI simple ( Fig. 21 G). Premandible with an outer lateral lamellae with a brush. Mentum with three median teeth, intermediate teeth minute and six adjacent teeth ( Fig. 21 J). Distance between setae submenti 50–57 µm. Mandible ( Fig. 21 H) length 47–50 µm with outer sclerotized protuberance. Antennae ( Fig. 21 I). AR 0.95–1.02. Length of segment I 95 –110 µm, II 45 –47 µm, III 50 –55 µm, IV 5 µm; basal segment width 12 µm; antennal blade 30–37 µm long; ring organ at 20–25 µm from the base of first antennal segment. Antennal segments two and three brown.

Abdomen. Ventral setae modified, wide and longer ( Fig. 21 K). Anal setae length 75 µm. Subbasal seta on posterior parapod 135–137 µm long, with a serrate side ( Fig. 21 L).

Remarks All larvae of Corynoneura unicapsulata were collected from litter laying near the water surface from small mountain streams. This species was found in Minas Gerais, São Paulo, Paraná and Rio Grande do Sul States.

Figures

FIGURE 19. Corynoneura unicapsulata sp. n., male. A—terminal flagellomeres. B—thorax. C—wing. D—apex of hind tibia. E and F—hypopygium. E—tergite IX; left: dorsal view, right: ventral view. F—tergite IX removed, sclerites hatched; left: ventral view, right: dorsal view. G—gonostylus.

FIGURE 20. Corynoneura unicapsulata sp. n., female. A—wing. B, C and D—genitalia. B—dorsal with view of labia. Cventral view; left: gonapophysis removed. D—ventral view of labia.

FIGURE 21. Corynoneura unicapsulata sp. n., immatures. A – F—pupa. A—frontal apotome. B—thorax, lateral view. Ctergites I – IX and anal lobe, left: without fringe. D—sternites I – VIII. E—detail of tergite IV. F—detail of posterior shagreen of tergite IV. G – L—larva. G—labrum. H—mandible. I—antenna. J—mentum. K—abdominal setae. L—sub-basal seta of posterior parapod.

Tables

TABLE 14. Leg measurements (in µm) and ratios of Corynoneura unicapsulata sp. n., female (n = 2).

p1	162–170	170–245	87–95	42–63	22–33	17	15–25	0.39–0.51	3.71–4.31	3.80–4.37	2.0–2.50
p2	225–280	205–255	135–165	52–70	27–35	15	22–25	0.62–0.66	4.79–4.81	3.18–3.34	2.33–2.75
p3	162–205	200–230	100–128	62–70	25–30	15	22–25	0.50–0.55	3.70–4.02	3.41–3.63	1.5–2.50