Corynoneura sertaodaquina, 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 : 26-29

Corynoneura sertaodaquina sp. n.

( Figs 16–18 )

Type material. Holotype male with pupal exuviae, BRAZIL, SP, Ubatuba, Sertão da Quina, Cachoeira da Renata upstream, 23˚30.789´S, 45˚14.442´W, 61 m a.s.l., 04.i.2008, S. Wiedenbrug. Paratypes: allotype female, with pupal and larval exuviae same data as holotype but 15.i.2008; one male with pupal and larva exuviae same data as holotype except for Sertão da Quina, Sítio Santa Cruz, Cachoeira do Engenho, 23˚31.068´S, 45˚14.845´W, 23 m a.s.l., 8.x.2007, S. Wiedenbrug; one female with pupal exuviae and larval skin same data as holotype but 15.x.2008.

Diagnostic characters. The adult males are separable from other species by the antenna with 11 flagellomeres, with more than one row of seta on each flagellomere, last flagellomere subequal to preceding two, eyes bare, AR 0.2, superior volsella absent, attachment of the phallapodeme caudal on the lateral sternapodeme, phallapodeme paddle shaped, gonostylus tapering apically. Adult females are separable from other species but from C. septadentata and C. sp. sexadentata by the labia funnel shaped, one large seminal capsule sclerotized, the second less chitinized difficult to see, gonapophysis posterior median margin straight. The pupae are distinguished from other species except from C. sp. circulimentum by having spines of shagreen on tergites IV and V increasing in size posteriorly, sternites II and III with minute spines, 4 LS-setae on segments III–VIII, anal lobe rectangular, less than one fourth of the anal lobe lateral margin with short and thin setae, posterior margin with fringe. The larvae can be recognized by the mentum with 7 median teeth, head not elongated (post mentum length/ head length ˂ 1), antenna slightly smaller as post mentum, AR 1.3, frontal apotome about 140 µm long, modified abdominal seta apically split and basal seta on posterior parapod with one pectinate side.

Etymology. Named after Sertão da Quina, the locality where type material was collected.

Description. Male (n = 1, holotype)

Total length 0.88 mm. Wing length 0.50 mm. Total length/wing length 1.76. Wing length/length of profemur 3.28.

Color. Thorax brownish; legs whitish; tergites I–III whitish, IV brownish in the median area, V–IX brownish.

Head. AR = 0.2. Antenna with 11 flagellomeres, ultimate flagellomere 48 µm long; two sensilla chaetica at last flagellomere. Flagellomeres with more than one rows of setae ( Fig. 16 A). Temporal setae absent. Clypeus 27 µm long, with 8 setae. Tentorium 87 µm long. Palpomere lengths (in µm): 10, 10, 15, 17, 42. Third palpomere with one sensilla clavata. Eyes bare.

Thorax. Antepronotum apparently without setae. Dorsocentrals 3, prealars 2. Scutellars 2. Antepronotal lobes dorsally reduced.

Wing ( Fig. 16 B). Clavus 37 µm wide, ending 115 µm from arculus. Clavus/wing length 0.23. Anal lobe absent.

Legs. Spur of front tibia 17 µm long, scale 7 µm long; spur of mid tibia 10 µm long, scale 2 µm long; spurs of hind tibia 27 µm long, second spur s-shaped. Width of apex of front tibia 15 µm, of mid tibia 12 µm, of hind tibia 27 µm. Fore tibial scale 7 µm long, mid tibial scale 2 µm long, hind tibial scale 40 µm long. Leg measurements (in µm) and ratios as in Table 11.

fe ti ta1 ta2 ta3 ta4 ta5 LR BV SV BR p1 153 185 88 53 25 13 22 0.47 3.77 3.86 1.50 p2 235 200 125 53 25 13 23 0.63 4.98 3.48 3.33 p3 175 187 93 55 23 15 23 0.49 3.96 3.92 2.50 Abdomen. One seta on TVII, 1 on TVIII.

Hypopygium ( Figs 16 C–D). Tergite IX with 3 small setae. Laterosternite IX with 1 seta. Superior volsella absent. Inferior volsella smooth with longer microtrichia medially directed. Phallapodeme paddle-shaped, 27 µm long; transverse sternapodeme rounded. Gonocoxite 55 µm long. Gonostylus tapering apically not possible to measure; megaseta 5 µm long. HR 5.5; HV 8.8.

Female (n = 1)

Total length 0.76 mm. Wing length 0.52 mm. Total length/ wing length 1.48.

Color. Thorax light brown; legs whitish; abdomen, light brown, tergite VI and VII apparently whitish.

Head. AR 0.42. Antenna with 5 flagellomeres; apical flagellomere 45 µm long; one sensilla chaetica on flagellomeres 2–4 and two on flagellomere 5. Temporal setae absent. Clypeus 37 µm long, with 7 setae. Tentorium 62 µm long, 2 µm wide. Palpomere lengths (in µm): 10, 10, 15, 12, 40. Sensilla clavata not possible to see. Eyes bare.

Thorax. Dorsocentrals 4, prealars 2. Scutellum with 2 setae. Antepronotal lobes dorsally tapering.

Wing ( Fig. 17 A). VR 2.00. Clavus 25 µm wide, ending 227 µm from arculus. Clavus/wing length 0.44.

Legs. Spur of front tibia 5 µm long; spur of middle tibia 5 µm long; spurs of hind tibia 27 µm long, second spur small s-shaped. Hind tibial scale 37 µm long. Width of apex of front tibia 15 µm, of middle tibia 15 µm, of hind tibia 20 µm. Leg measurements (in µm) and ratios as in Table 12.

fe ti ta1 ta2 ta3 ta4 ta5 LR BV SV BR p1 135 165 65 38 20 13 20 0.39 4.06 4.61 2.00 p2 195 175 103 43 23 13 13 0.56 5.25 3.61 2.00 p3 158 155 90 48 18 13 23 0.58 4.02 3.47 1.40 Abdomen. One seta on TVI, 1 on TVII.

Genitalia ( Figs 17 B–C). Gonocoxite IX with 1 seta. Tergite IX with 4 setae. Seminal capsule 30 µm and spermathecal duct long with a loop, second seminal capsule less sclerotized apparently absent with spermathecal duct straighter, both ducts join together short before seminal eminence, which has sclerotized outer borders. Notum 25 µm long. Membrane median curved to posterior, less sclerotized on the link of both sides. Apodeme lobe anterior margin in the same shape as membrane, apically pointed. Coxosternapodeme apparently without lateral lamellae, strongly curved, one strongly sclerotized end at the roof of copulatory bursa, last semicircle-shaped. Labia, membranous, bare, separated, apparently funnel shaped as C. septadentata . Gonocoxapodeme straight, gonapophyses slightly medially lobed. Post genital plate with few microtrichia. Cercus 25 µm long.

Pupa (n = 1–2)

Total length 1.06 mm.

Cephalothorax. Frontal apotome not granulated. Frontal setae 100 µm long. Postorbitals 30 µm and 25 µm. Median antepronotals 25 µm and 20 µm. Lateral antepronotals 12 µm. Dorsocentrals Dc1 25 µm long. Distance between Dc1 and Dc2 70 µm; Dc2 and Dc3 40 µm; Dc3 and Dc4 22 µm. Dc1 displaced ventrally. Wing sheath with one row of pearls.

Abdomen ( Figs 18 A–D). Tergite I and sternite I without shagreen. Tergite II with few shagreen points. Tergites III–VIII with fine shagreen grading to a row of slightly stronger points posteriorly ( Fig 18 C–E). Tergite IX with shagreen. Sternites II–III with shagreen of very fine spinules, IV–VIII with fine shagreen. Sternite VIII on female bare. Conjunctive TII/III with 11–14 hooklets; TIII/IV with 13 hooklets; TIV/V with 13 hooklets; TV/VI with 0–8 hooklets; TVI/VII and TVII–VIII without hooklets, with a row of small spinules; SIV/V with 8 hooklets; SV/VI with 0–10 hooklets; SVI/VII with 0–8 hooklets, SVII/VIII with 0–5 hooklets.

Segment I with 3 D-setae, 1 L-setae, 1 V-setae; segment II 3 D, 3 L and 3V-setae; segment III 3 D, 3 V and 4 short and taeniate L-setae; segments IV–VII with 4 D, 3V and 4 taeniate L-setae; segment VIII with 2 D, 1 V and 4 taeniate L-setae.

Anal lobe rectangular 75–87 µm long ( Fig. 18 D). Anal lobe fringe with 2 lateral fine and shorter setae and posterior 12–13 taeniate setae 250–275 µm long with about 1 thinner and shorter median setae; 3 macrosetae taeniate; inner setae taeniate.

Larva (n = 1).

Head. Head capsule integument smooth. Frontal apotome 140 µm long, head width 120 µm. Postmentum 107 µm. Postmentum/head width 0.90. SI simple. Premandible with an outer lateral lamellae with a brush. Mentum with seven median teeth, intermediate teeth minute and four adjacent teeth ( Fig. 18 F). Distance between setae submenti 37 µm. Mandible length 37 µm with outer sclerotized protuberance. Antennae ( Fig. 18 G). AR 1.33. Length of segment I 60 µm, II 20 µm, III 20 µm, IV 5 µm; basal segment width 10 µm; antennal blade 20 µm long; ring organ at 12 µm from the base of first antennal segment. Third antennal segment with wall from one side not sclerotized. Antennal segments two and three brown.

Abdomen. At least 2 anterior segments with a pair of modified ventral setae, pectinate ( Fig. 18 H). Anal setae length 75 µm Subbasal seta on posterior parapod 55 µm µm long, with a serrate side ( Fig. 18 I).

Remarks. C. septadentata , C. sertaodaquina , C. sp. sexadentata and C. sp. circulimentum are similar to each other. More material and DNA analyses would be necessary to clear relationship between this species.

Larva of c. sertaodaquina was collected from the surface of stones of shallow fast flowing waters and also from litter laying near the water surface of streams.

Figures

FIGURE 16. Corynoneura sertaodaquina sp. n., male. A—terminal flagellomeres. B—wing. C and D—hypopygium. Ctergite IX; left: dorsal view, right: ventral view. D—tergite IX removed, sclerites hatched; right: ventral view, left: dorsal view.

FIGURE 17. Corynoneura sertaodaquina sp. n., female. A—wing. B—dorsal view of genitalia with labia, right: dorsal view of labia, left: ventral view of labia. C—ventral view of genitalia; left: gonapophysis removed.

FIGURE 18. Corynoneura sertaodaquina sp. n., immatures. A – E—pupa. A—sternites II – III. B—tergite II. C—tergite IV. D—segment VIII and anal lobe, left: ventral, right: dorsal view, without fringe. E—detail of posterior shagreen of tergite IV. F – I—larva. F—mentum. G—antenna. H—abdominal setae. I—sub-basal seta of posterior parapod.