Corynoneura fortispicula, 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 : 2-7

Corynoneura fortispicula sp. n.

( Figs 1–3 )

Corynoneura -Gruppe spec. 5: Wiedenbrug 2000: 102

Type material. Holotype male with pupal and larval exuviae, BRAZIL, SP, Ubatuba, stream beside Ruínas da Lagoinha, 23˚30.468´S, 45˚11.923´W, 0 m a.s.l., 1.vii.2008, S. Wiedenbrug. Paratypes: allotype female with pupal and larval exuviae, same data as holotype but stream beside Ruínas da Lagoinha, Cachoeira do Véu, 23°30.404´S, 45°12.340´W, 116 m a.s.l., 29.xii.2009, S.Wiedenbrug; one male with pupal exuviae same data as holotype but 11.iv.2009 (UFSCAR MPSW 048); one female with pupal and larval exuviae same data as holotype but 5.i.2010; one 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., 2.iii.2008, S. Wiedenbrug; three males and three females all with pupal and larval exuviae), MG, Paraisópolis, Distrito dos Costa, 22°39´54.81”S, 45°55´38.29”W, approx. 1370 m a.s.l., 11.x.2009, S.Wiedenbrug (UFSCAR MPSW 0 33, 035,043).

Diagnostic characters. The adult males are separable from other species except C. hirvenojai by the antenna with 7 flagellomeres, 6 distinct separated and the last composed of 5 fused flagellomeres, antenna sparsely plumose with one row of seta on each flagellomere, AR 1.0–1.3; eyes pubescent; abdominal tergites I–IV whitish, V–IX brown; attachment of the phallapodeme caudal on the lateral sternapodeme, phallapodeme with posterior margin sclerotized, rounded and curved anteriorly; gonostylus slender, tapering apically. Adult females are separable from other species by the funnel shaped labia, seminal capsules size subequal, abdominal segments IV–IX brownish, III median whitish, lateral brownish. The pupae are distinguished from other species by the shagreen of tergites IV and V with posterior row of strong spines longer than wide ( Fig. 3 F), pearl row usually present, 3 short lateral setae on segments IV–VII, if four the last minute, anal lobe rectangular, anal lobe fringe restricted to posterior margin. The larvae can be recognized by the head integument without sculptures, mentum with 3 median teeth and 6 lateral teeth, antenna longer than postmentum, AR 0.76–0.88, second antennal segment subequal or shorter than the third, basal seta on posterior parapods split from the base.

Etymology. From Latin fortis meaning strong and spiculum meaning sharp point, referring to the posterior strong shagreen spines on the pupal abdominal tergites.

Description. Male (n = 1–4)

Total length [0.75] mm. Wing length [0.47]. Total length/wing length [1.58]. Wing length/ length of profemur [3.17].

Color. Thorax brownish; legs whitish, brownish ring on apex of femur and proximal tibia; tergites I–IV whitish, V–IX brownish.

Head. AR = [1.05]–1.34. Antenna with [7] flagellomeres, flagellomeres 1–6 distinctly separated from each other, ultimate flagellomere [105]–160 µm long, composed of 5 distinct but fused flagellomeres ( Fig. 1 A), two sensilla chaetica at the apex of the last flagellomere. Flagellomeres, except first and last, with one row of seta each, fused flagellomeres also with one row of setae each. Temporal setae absent. Clypeus [30]–32 µm long, with 6–7 setae. Tentorium 93 µm long; 5 µm wide. Palpomere lengths (in µm): 7, 10, [12], [17], [35]–42.Third palpomere with one sensilla clavata. Eyes pubescent.

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

Wing ( Fig. 1 C). VR 2.93–[4.64]. Clavus [27]25–35 µm wide, ending 112–125[115] µm from arculus. Clavus/ wing length [0.24] –0.25. Anal lobe absent.

Legs. Spur of front tibia [20]–22 µm long; spur of middle tibia [5] and [5]–12 µm long; spurs of hind tibia [30] µm long, second spur s-shaped. Width of apex of front tibia [12]–17 µm, of middle tibia [12]–15µm, of hind tibia 30–[32] µm ( Fig 1 D). Front tibial scale 7–[10] µm long; hind tibial scale [37]–42 µm long. Leg measurements (in µm) and ratios as in Table 1.

fe ti ta1 ta2 ta3 ta4 ta5 LR BV SV BR p1 150–178 182–220 75–90 50–63 30–35 15–20 22–25 0.40–0.41 3.42–3.47 4.41–4.43 1.50–2.00 p2 217–248 195–215 102–125 52–65 27–33 15 22 0.52–0.58 4.35–4.38 3.70–4.03 1.75–2.50 p3 162–200 170–200 92–103 55– 65 20–25 12–15 22–25 0.51–0.54 3.78–3.94 3.59–3.90 1.75–2.50 Abdomen setation. Tergite VI 0–1, VII 3, VIII 1.

Hypopygium ( Figs 1 E–F). Tergite IX with 2 setae. Laterosternite IX with 0–1 seta. Superior volsella absent. Inferior volsella smooth with longer microtrichia directed to median. Phallapodeme [22]–25 µm long, rounded and sclerotized on posterior margin; transverse sternapodeme [12]–15µm long. Gonocoxite [60]–67 µm long. Gonostylus tapering apically, 17 µm long; megaseta 5–[10] µm long. HR 3.86.

Female (n = 1–2)

Total length 0.91–0.93 mm. Wing length 0.63 mm. Total length/wing length 1.45. Wing length/length of profemur 3.98.

Color. Thorax brownish; legs whitish with brown ring posterior on femur and anterior on tibia; tergites I–II whitish, III whitish on median region brownish lateral, IV–IX brownish.

Head. AR 0.37–0.50. Antenna with 5 flagellomeres, apical flagellomere 37–50 µm long; two sensilla chaetica on flagellomeres 3–5, first and second flagellomeres not possible to observe. Temporal setae absent. Clypeus 25 µm long, with 8 setae. Tentorium 60–65 µm long, 2–4 µm wide. Palpomere lengths (in µm): 7–10, 10, 15, 17, 35– 40. One sensilla clavata on third palpomere. Eyes pubescent.

Thorax. Antepronotals 2 median, 1 lateral. Dorsocentrals 2, prealars 2. Scutellars 2. Antepronotal lobes dorsally tapering.

Wing ( Fig. 2 A). VR 2.64. Clavus 37 µm wide, ending 247 µm from arculus. Clavus/wing length 0.40.

Legs. Spur of front tibia 12 µm long; spur of middle tibia 10 µm; spurs of hind tibia 30–32 µm long, second spur small s-shaped. Front tibial scale 10 µm long, hind tibial scale 32–40 µm long. Width of apex of front tibia 12–15 µm, of middle tibia 12–15 µm, of hind tibia 30–32 µm. Leg measurements (in µm) and ratios as in Table 2.

fe ti ta1 ta2 ta3 ta4 ta5 LR BV SV BR p1 147–157 177–210 75–77 47–52 27 15–17 20–25 0.37–0.42 3.55–3.77 4.33–4.74 2.00 p2 210–225 195–237 107–120 50–52 25–30 15–17 20–22 0.50–0.55 4.55–4.85 3.76–3.85 1.75–2.33 p3 150–205 175–200 77–102 47–60 22–25 15 22 0.44–0.51 3.74–4.14 3.95–4.19 2.00 Abdomen. One seta on TVI, 3 on TVII, 1 on TVIII.

Genitalia ( Figs 2 B–D). Gonocoxite IX with 1 seta. Tergite IX with 2 setae. Two seminal capsules respectively 37 µm and 42 µm long; one spermathecal duct with a loop, second straighter, both ducts join together shortly before seminal eminence, which has sclerotized outer borders. Notum 30–35 µm long. Membrane well sclerotized. Apodeme lobe well sclerotized, apically pointed. Coxosternapodeme, with one tiny lateral lamellae, strongly curved, coxosternapodeme with one end at roof of copulatory bursa, last semicircle-shaped. Labia membranous, bare, separated, dorsal funnel shaped, apically building the accessory gonopore(?),ventral divided in two lobes. Gonocoxapodeme straight, gonapophyses median smoothly pointed. Post genital plate squared with few microtrichia. Cercus 27–30 µm long.

Pupa (n = 1–6)

Total length 1.32 mm.

Cephalothorax. Frontal apotome granulated ( Fig. 3 A). Frontal setae 45–57 µm long. Median antepronotals 32– 60 µm. Distance between Dc1 and Dc2 57–70 µm; Dc2 and Dc 3 22–27 µm; Dc3 and Dc 4 10–20 µm. Dc1 displaced ventrally. Wing sheaths with one row of pearls, sometimes difficult to see.

Abdomen ( Figs 3 B–F). Tergite I, sternite I–II and usually III without shagreen. Tergite II with few shagreen points. Tergites III–VI with fine shagreen grading to a row of stronger spines posteriorly, particularly strong on tergite IV and V ( Figs 3 E–F). Tergites VII–IX with shagreen with spinules of the same size. Sternites III–IV and VIII with fine shagreen posteriorly, V–VII with fine shagreen. Sternite VIII on female with few shagreen points. Conjunctive TII/III with 0–24 spinules; TIII/IV with 18–30 hooklets; TIV/V with 15–31 hooklets; TV/VI with 0–5 spinules; TVI/VII with 0–2 spinules; SIV/V with 13–22 spinules; SV/VI with 13–27 spinules; SVI/VII with 13–26 spinules, SVII/VIII with 6–20 spinules. Segment I with 4 D-setae, 1 L-setae, without V-setae; segment II–IV 4 D, 3 L-setae and 3 V-setae; segment V–VII 4 D, 3V-setae and 3 thin taeniate L-setae, on segment VI–VII sometimes one additional minute L4-setae; segment VIII with 1 D, 1 V and 3 short taeniate L-setae and sometimes one additional minute L4-setae. O setae visible from TII–VII.

Anal lobe rectangular 82–102 µm long ( Fig. 3 D). Anal lobe fringe posteriorly with 8–11 taeniate setae 200– 450 µm long, one median and 1–3 lateral thin and shorter fringe setae; 3 macrosetae taeniate; inner setae taeniate.

Larva (n = 1–4)

Head ( Fig. 3 G). Head capsule integument smooth. Frontal apotome 137–170 µm long; head width 100–117 µm; post mentum 110–127 µm; postmentum/head width 1.08–1.11. SI simple ( Fig. 3 H). Premandible with the outer lateral lamellae with brush. Mentum with three median teeth, intermediate teeth minute and six adjacent teeth ( Fig. 3 K). Distance between setae submenti 35–40 µm. Mandible length 37 µm. Antennae ( Figs 3 I–J). AR 0.76– 1.00. Length of segment I 60 –75 µm, II 30–45 µm, III 27–47 µm, IV 2–5 µm; part of the third antennal segment not sclerotized; basal segment width 12 µm; antennal blade 27–37 µm long; ring organ at 10–20 µm from the base of first antennal segment. Antennal segments two and three brown.

Abdomen. Ventral setae modified, slightly wider and longer than dorsal setae( Fig. 3 L). Subbasal seta on posterior parapod split from base ( Fig. 3 M).

Remarks. The larvae from C. fortispicula were collected from litter standing near the water surface from small mountain streams. This species was found in Minas Gerais, São Paulo and Rio Grande do Sul States. See comments on C. hirvenojai .

Figures

FIGURE 1. Corynoneura fortispicula 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; right: dorsal view, left: ventral view.

FIGURE 2. Corynoneura fortispicula sp. n., female. A—wing. B, C and D—genitalia. B—dorsal view with view of labia. C—ventral view; left: gonapophysis removed. D—ventral view of labia.

FIGURE 3. Corynoneura fortispicula sp. n., immatures. A – F—pupa. A—frontal apotome. B—abdomen, dorsal view. Csternites I – VIII. D—detail of anal lobe; left: dorsal view without fringe, right ventral view. E—detail of tergite IV. F—detail of posterior shagreen of tergite IV. G – M—larva. G—dorsal view of the head and antenna. H—dorsal view of labrum. I—antenna. J—detail of lauterborn organs. K—mentum. L—abdominal seta. M—sub-basal seta of posterior parapod.