Corynoneura hermanni, 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 : 7-11

Corynoneura hermanni sp. n.

( Figs 4–7 )

Corynoneura -Gruppe spec.4: Wiedenbrug 2000: 101

Type material. Holotype male with pupal exuviae, BRAZIL, SP, Ubatuba, stream beside Ruínas da Lagoinha, 23˚30.468´S, 45˚11.923´W, 0 m a.s.l., 10.x.2008, S. Wiedenbrug. Paratypes: allotype female with pupal and larval exuviae, Ubatuba, Sertão da Quina, Cachoeira da Renata upstream, 23˚30.789´S, 45˚14.442´W, 61 m a.s.l., 21.iii.2008, S. Wiedenbrug; one female with pupal and larval exuviae same data as allotype but 4.i.2008.

Diagnostic chara cters. The adult males are separable from other species by the antenna with 10 flagellomeres, AR 0.27; eyes pubescent; hypopygium with superior volsella bearing long setae directed to median, attachment of the phallapodeme caudally on the lateral sternapodeme, phallapodeme posterior margin sclerotized, rounded, curved to anterior, crista dorsalis absent on gonostylus. Adult females are separable from other species except C. mediaspicula by the labia being funnel shaped, two seminal capsules subequal in size and abdominal segments III– IX brownish. The pupae are distinguished from other species by the median field of shagreen on tergites III and IV not separated from posterior field. Spines of posterior row narrow, with straight lateral margin. Anal lobe not joined medially as an inverted “v” but separated through a straight margin, posterior margin rounded with fringe. The larvae can be recognized by the head integument without sculptures, the mentum with 2 median and 6 lateral teeth, antenna longer than frontoclypeal apotome, head elongate (postmentum length/head width 1.35), AR 0.88, modified abdominal setae apically split, basal seta on posterior parapods with one slightly pectinate side.

Etymology. Named after Hermann Göb, who helped and supported the first author during the sampling and elaboration of this paper.

Description. Male (n = 1, holotype)

Thorax length 0.35 mm.

Color. Thorax brownish; legs whitish with brownish ring posterior on femur and anterior on tibia; tergites I–IV whitish, V–IX brownish in anterior half, rest whitish.

Head. AR = 0.27. Antenna with 10 flagellomeres, ultimate flagellomere 55 µm long, at least one sensillum chaeticum on last flagellomere ( Fig. 4 A). Flagellomeres, except the first and last, with more than one rows of seta. Temporal setae absent. Clypeus 37 µm long, with 8 setae. Tentorium 77 µm long. Palpomere lengths (in µm): 7, 10, 15, 17, 32. Sensilla clavata not possible to see. Eyes pubescent.

Thorax ( Fig. 4 B). Antepronotum apparently without setae. Dorsocentrals 4, prealars 2. Scutellars 2. Antepronotal lobes dorsally reduced.

Wing. Not measurable.

Legs. Spur of front tibia 10 µm long, scale 5 µm long. Width of apex of front tibia 12 µm. Leg measurement (in µm) and ratios as in Table 3.

fe ti ta1 ta2 ta3 ta4 ta5 LR BV SV BR p1 – 177 85 50 27 15 22 0.48 – – 4.00 Abdomen setation. Three setae on TVII, 1 on TVIII.

Hypopygium ( Figs 4 C–D). Tergite IX with 4 small setae with wide posterior hyaline projection bearing microtrichia. Laterosternite IX with 1 seta. Superior volsella rounded with long seta directed medially. Inferior volsella prominent with longer microtrichia medially directed. Phallapodeme 17 µm long, with posterior margin rounded and sclerotized; transverse sternapodeme rounded. Gonocoxite 37 µm long. Gonostylus 12 µm long, apically tapering; megaseta 5 µm long. HR 3.

Female (n = 1)

Thorax length 0.70 mm. Wing length 0.55 mm. Wing length/ length of profemur 3.18. Color. Thorax light brown, with brown vittae, postnotum and preepisternum; legs whitish with a brown ring anterior on tibia; tergites I–II whitish, III–IX brownish, with posterior whitish band.

Head. AR 0.3. Antenna with 5 flagellomeres, apical flagellomere 30 µm long; two sensilla chaetica on flagellomeres 5, at least one on 3–4, first and second flagellomeres not possible to observe. Temporal setae absent. Clypeus 45 µm long, with 8 setae. Tentorium 75 µm long, 5 µm wide. Palpomeres length (in µm): 10, 12, 15, 20, 45. One sensilla clavata on third palpomere. Eyes pubescent.

Thorax. Antepronotal not possible to observe. Dorsocentrals 4, prealars 2. Scutellars 2. Antepronotal lobes dorsally tapering.

Wing ( Fig. 5 A). VR 2.60. Clavus 35 µm wide, ending 245 µm from arculus. Clavus/wing length 0.45.

Legs. Spur of front tibia 10 µm long; spur of middle tibia 7 µm; spurs of hind tibia 32 µm long, second spur small s-shaped. Front tibial scale 10 µm long, Mid tibial scale 12 µm long, hind tibial scale 35 µm long. Width of apex of front tibia 15 µm, of middle tibia 15 µm, of hind tibia 25 µm. Leg measurements (in µm) and ratios as in Table 4.

fe ti ta1 ta2 ta3 ta4 ta5 LR BV SV BR p1 172 200 92 50 27 15 25 0.46 3.96 4.03 1.75 p2 235 220 127 52 27 15 22 0.58 4.96 3. 57 2.25 p3 190 205 107 60 22 12 22 0. 52 4.28 3.67 3. 0 0 Abdomen. One seta on TVI, 3 on TVII, 1 on TVIII.

Genitalia ( Figs 5 B–D). Gonocoxite IX with 1 seta. Tergite IX with 2 setae. Two seminal capsules respectively 30 µm and 32 µm long, one spermathecal duct with a loop, second straighter both ducts join together a short distance before seminal eminence, which has sclerotized outer borders. Notum 50 µm long. Membrane well sclerotized. Apodeme lobe anterior margin curved to posterior, apically pointed. Coxosternapodeme strongly curved, apparently without lateral lamellae, copulatory bursa semicircle-shaped. Labia membranous, bare, dorsal funnel shaped, apically building the accessory gonopore(?), ventral shorter. Gonocoxapodeme straight, gonapophyses triangular medially. Post-genital plate with microtrichia. Cercus 30 µm long.

Pupa (n = 1–3)

Total length 1.21 – 1.41 mm.

Cephalothorax. Frontal apotome smooth or with few granulations ( Fig. 6 A). Distance between Dc1 and Dc2 60– 65µm; Dc2 and Dc3 35–45 µm; Dc3 and Dc 4 20–25 µm. Dc1 displaced ventrally. Wing sheath with one, sometimes two, row of pearls ( Fig. 6 B).

Abdomen ( Figs 6 C–G). Tergite I and sternite I–II without shagreen. Tergite II–III with few shagreen spinules posteriorly. Tergites VI–IX with fine shagreen, shagreen points slightly increasing in size posteriorly on segments III–V ( Fig. 6 F–G). Sternites III–IV with fine shagreen posteriorly, IV–VIII with fine shagreen. Conjunctive TII/III with 7 spinules; TIII/IV with 19 hooklets; TIV/V with 13 hooklets; TV/VI with 9 spinules; SIV/V with 12 spinules; SV/VI with 13 spinules; SVI/VII with 11 spinules, SVII/VIII with 9 spinules. Segment I with 4 D-setae, 1 L-setae, without V-setae; segment II-III 3 D, 3 L-setae and 3 V-setae; segment IV-VII 3–4 D, 3V-setae and 3 short taeniate L-setae; segment VIII with 2 D, 1 V and 4 taeniate L-setae.

Anal lobe distally rounded 87–95 µm long ( Fig. 6 E), posterior with 21–24 taeniate setae 130 µm long; 3 macrosetae taeniate; inner setae taeniate.

Larva (n = 1–2)

Head. Head capsule integument smooth. Frontal apotome 190–195 µm long; head width 120 µm; postmentum 155–162 µm long; postmentum/head width 1.35. SI simple. Premandible not possible to see. Mentum with two median teeth and six adjacent teeth ( Fig. 6 I). Distance between setae submenti 32–35 µm. Mandible ( Fig. 6 H) length 37–40 µm with outer sclerotized protuberance. Antennae ( Fig. 6 J). AR 0.88. Length of segment I 125 µm, II 60 µm, III 77 µm, IV 5 µm; basal segment width 12 µm; antennal blade 27 µm long; ring organ at 35 µm from the base of first antennal segment. Lauterborn organs inserted on second antennal segment not overreaching distal bor- der of segment. Antennal segments two and three brown.

Abdomen. Ventral setae modified, slightly wider and slit at extremity ( Fig. 6 K). Subbasal seta on posterior parapod as figure 6L.

Remarks. The larvae from C. hermanni were collected from litter standing near the water surface from small mountain streams. This species was found in São Paulo and Rio Grande do Sul States.

Figures

FIGURE 4. Corynoneura hermanni sp. n., male. A—terminal flagellomeres. B—thorax. C and D—hypopygium. C—tergite IX; left: dorsal view, right: ventral view. D—tergite IX removed, sclerites hatched; left: dorsal view, right: ventral view.

FIGURE 5. Corynoneura hermanni sp. n., female. A—wing. B, C and D—genitalia. B—dorsal with view of labia. C—ventral view; left: gonapophysis removed. D—ventral view of labia.

FIGURE 6. Corynoneura hermanni sp. n., immatures. A – G—pupa. A—frontal apotome. B—thorax, lateral view. C—tergites I – IX and anal lobe, right: ventral, left: dorsal without fringe. D—sternites I – VIII. E—detail of anal lobe; right: dorsal view without fringe, left ventral view. F—detail of tergite IV. G—detail of posterior shagreen of tergite IV. H – L—larva. H—mandible. I—mentum. J—antenna. K—abdominal seta. L—sub-basal seta of posterior parapod.

FIGURE 7. Corynoneura mediaspicula sp. n., male. A—head, dorsal view, left, sclerites hatched. B—terminal flagellomeres. C—thorax. D—wing. E—apex of hind tibia. F and G—hypopygium. F—tergite IX; left: dorsal view, right: ventral view. Gtergite IX removed, sclerites hatched; right: dorsal view, left: ventral view. H—gonostylus.