Thienemanniella sancticaroli, Wiedenbrug, Sofia, Lamas, Carlos E. & Trivinho-Strixino, Susana, 2013

Wiedenbrug, Sofia, Lamas, Carlos E. & Trivinho-Strixino, Susana, 2013, A review of Neotropical species in Thienemanniella Kieffer (Diptera, Chironomidae), Zootaxa 3670 (2), pp. 215-237 : 224-229

Thienemanniella sancticaroli sp. n.

( Figs 5–7 )

Type material. Holotype male with pupal and larval exuviae; BRAZIL, SP, São Carlos, UFSCar, Concrete spillway of the Fazzari Reservoir, 18.XII.2008, S. Wiedenbrug & S. Trivinho-Strixino, UFSCar SW030. Paratypes: allotype female with pupal and larval exuviae; same data as holotype, except UFSCar SW031; two females with pupal and larval exuviae; same data as holotype, except one of them UFSCar SW027.

Additional material examined. One pharate male with pupal exuviae, three pupal exuviae, MS, Bodoquena, fazenda Califórnia, 2° Riacho da trilha da Gruta, 1.VI.2012, S. Wiedenbrug (SISBIOTA-Project). One pupal exuviae, SP, Luiz Antônio, Estação Ecológica do Jataí, Lagoa do Diogo, 17.II.2011, S. Wiedenbrug.

Diagnostic characters. The adult male of T. sancticaroli sp. n. can be distinguished from other members of the group by the small oral projections of the transverse sternapodeme. The pupa has sternite I with very fine shagreen, tergite VIII with median and posterior shagreen of elongate spinules and on male pupae sternite VIII with median shagreen of short spinules and posterior shagreen of wide-based spinules. The larva is characterized by the yellow head capsule with smooth integument, mentum with central median tooth as dark as adjacent teeth, first lateral teeth narrow and adpressed to outer median teeth, antennal segments II and III brown, and length ratio antenna/postmentum 0.8–0.9.

Etymology. Named after the town of São Carlos, where the most specimens were collected.

Description. Male (n = 1). Wing length 0.65 mm.

Color. Thorax brownish. Abdomen apparently with tergites light brown, except for whitish areas around setal insertions and TVI–VII with white posterior rectangle. Legs whitish.

Head. AR = 0.45. Antenna with 12 flagellomeres, apical flagellomere 120 µm long. Flagellomeres with more than one row of setae each. Eyes hairy.

Wing. Clavus/wing length ratio 0.32. Anal lobe present ( Fig. 5 E).

Legs. Fore and hind trochanter with dorsal keel ( Fig. 5 A, B). Hind tibial scale small, 7 µm long, with one long curved seta and one short spur ( Fig. 5 C, D).

Tergite setae not discernible.

Hypopygium ( Fig. 5 F, G). Tergite IX with 8 setae. Laterosternite IX with 1 seta. Superior volsella triangular, with concave posterior margin. Inferior volsella present apically on gonocoxite, rounded. Transverse sternapodeme 35 µm long, with small oral-lateral projections; phallapodeme curved to posterior. Gonostylus with low crista dorsalis.

For measurements, see Table 1 .

Female (n = 1–3). Total length 1.02 mm. Wing length 0.64–0.74 mm. Head. AR = 0.43. Antenna with 5 flagellomeres, apical flagellomere 47–52 µm long. Flagellomeres with one row of setae each. Eyes hairy.

Wing. Clavus/wing length ratio 0.55. Anal lobe present ( Fig. 6 A). 6–7 setae at clavus in addition to marginal wing setae (not drawn).

Legs. Hind tibial scale 12 µm long, with one short spur and one long and curved seta. Hind Ta1 with 5 sensilla chaetica.

Tergites. TI with 2 setae; TII–V with 5; TVI–VII with 4, TVIII without setae.

Genitalia ( Fig. 6 B, C). Tergite IX with 4–6 setae. Laterosternite IX with 1–2 setae. Two subequal seminal capsules, 55–62 μm long; spermathecal ducts join shortly before seminal eminence. Notum 42–52 μm long. Apodeme lobe approximately lozenge-shaped, evenly sclerotized, brown. Coxosternapodeme curved. Copulatory bursa with oral median invagination and sclerotized oral borders. Labia membranous, bare. Gonocoxapodeme slightly curved. Cercus 30–35 μm long.

For measurements, see Table 2 .

Pupa (n = 1–3). Total length 1.81–1.94 mm.

Cephalothorax. Frontal apotome rugose. Thorax suture slightly rugose. Dc2 seta short and hairy, displaced ventrally, Dc1 and Dc3-4 long and taeniate. Wing sheath without pearl row.

Abdomen ( Fig. 7 A, B). Tergite I bare; T II–V with fine shagreen with the posterior spinules larger; T VI–VIII with homogeneous shagreen with the oral median spines slightly elongated. Sternite I with very fine shagreen; S II with elongated spinules; S III–VIII with fine shagreen; male sternite VIII with additional posterior row of widebased spinules. Tergal conjunctives I/II or II/III–VII/TVIII and sternal conjunctives III/IV–VII/VIII with small spinules. Segment I with 1 L-seta, II with 3 and III–VIII with 4 long taeniate L-setae. Anal lobe rounded, with almost complete fringe, 3 taeniate macrosetae and one taeniate median seta. Male genital sac with inner median margin oblique.

For measurements, see Table 3 .

Species T. biobio T. manihuales T. medialis T. sancticaroli T. ubatuba sp. n. sp. n. Sublette & Sasa sp. n. sp. n.

Character (n = 1) (n = 1) (n = 1–3) (n = 1–3) Larva (n = 4). Head. Postmentum 147–155 µm long. Head capsule integument yellow and smooth. Mentum with three median teeth, central tooth much smaller than adjacent teeth ( Fig. 7 C). First lateral teeth adpressed to outer median teeth. Antenna 122–135 µm long ( Fig. 7 D); segments two and three darker than first segment (not drawn).

Abdomen. Hair-like setae not modified. Posterior parapod with subbasal seta simple. For measurements, see Table 4.

TABLE 4. Mensural characters of 4th instar larvae in two neotropical Thienemanniella species; measurements in µm.

Remarks. T. sancticaroli sp. n. and T. ubatuba sp. n. (see below) are very similar. The existence of two separate species was first indicated by sequence analysis of mitochondrial COI gene fragments that showed high genetic distances (results are being published elsewhere). Morphological differences between the two species are found in the male pupa: in T. sancticaroli the posterior spines on sternite VIII are wider than long and Dc1 is distinctly displaced to ventral and in T. ubatuba the correspondent spines are as long as wide and Dc setae are in two pairs or slightly displaced to ventral.

Additional material from Jundiaí has been included in the material listed above as belonging to the T. spreta group. Although all life stages of those specimens are known, it was difficult to identify them. The pupa has a ventrally dislocated Dc1 as found in T. sancticaroli , but sternite VIII does not have the posterior wide-based spines typical for that species. Additionally, the larval antenna/postmentum length ratio is 0.94–0.97, i.e. between the values for T. sancticaroli and T. ubatuba . More material from different geographical areas is needed to evaluate whether or not separation of T. sancticaroli and T. ubatuba remains justified and/or whether the group contains additional cryptic species.

Figures

FIGURE 5. Thienemanniella sancticaroli sp. n., adult male. A. Fore trochanter. B. Hind trochanter. C – D. Apex of hind tibia in posterior (C) and anterior view (D). E. Wing. F – G. Hypopygium. F. Tergite IX (part) and gonostylus. G. Tergite IX and gonostyli removed, internal sclerites hatched; left: ventral view, right: dorsal view.

FIGURE 6. Thienemanniella sancticaroli sp. n., adult female. A. Wing. B – C. Genitalia. C. Dorsal view, also showing coxosternapodemes and labia. B. Ventral view.

FIGURE 7. Thienemanniella sancticaroli sp. n., immature stages. A – B. Pupa. C – D. Larva. A. Abdominal segments I – III; left: dorsal view, right: ventral view. B. Segments VII – IX and anal lobes; in dorsal view (left) and ventral view (right). C. Mentum. D. Antenna.

Tables

TABLE 2. Mensural characters of adult females of two neotropical Thienemanniella species; measurements in µm. Species T. sancticaroli sp. n. T. ubatuba sp. n.

Character	(n = 1–3)	(n = 1–2)
Thorax length	420	–
Abdomen length	600–770	560
AR	0.43	0.40
Apical flagellomere length	47–52	40
No. of flagellomeres	5	5
No. of clypeals	9–10	8
Palpomere 3 length	27–30	22
Palpomere 4 length	40–45	32
Palpomere 5 length	100–110	77
No. of dorsocentrals	–	–
No. pf prealars	–	–
No. of scutellars	–	–
Wing length	640–740	570–670
Length ratio clavus/wing	0.55–0.56	0.54
LR1	0.77	0.76
BV1	4.43	4.24
SV1	2.62	2.59
LR2	0.68	0.72
BV2	4.85	4.50
SV2	3.12	3.00
LR3	0.69	0.66
BV3	4.54	3.95
SV3	2.74	2.95
Ti3 scale length	12	7
Width of Ti3 apex	27	25
Seminal capsule length	55–62	50
Notum length	42–52	40
Cercus length	30–35	22

TABLE 3. Mensural characters of pupae of neotropical Thienemanniella species; measurements in µm; " No. of spines cT " and " No. of spines cS " refer to dorsal and ventral conjunctives, respectively.

Thorax length	580	–	490	610–620	455–600
Abdomen length	940	–	800	1000–1325	970–1200
Frontal seta length	62	–	–	75	110
Distance Dc1–Dc2	15	6	–	55–57	10–12
Distance Dc2–Dc3	140	52	–	110–130	80–130
Distance Dc3–Dc4	10	4	–	7–10	10–12
No. of spines cT I/II				0, 7–9
No. of spines cT II/III	9	0	about 13	7–12	5–6
No. of spines cT III/IV	12	16	14	9–15	7–14
No. of spines cT IV/V	11	23	18	8–14	9–15
No. of spines cT V/VI	9	18	14	9–12	10–15
No. of spines cT VI/VII	12	16	0	8–9	10–14
No. of spines cT VII/VIII	3 (small)	0	0	7–8	10–12
No. of spines cS III/IV	6	0	0	7–11	6–8
No. of spines cS IV/V	8	16	about 5	7–12	9–10
No. of spines cS V/VI	11	14	about 5	8–11	8–12
No. of spines cS VI/VII	9	14	8	8–10	8–10
No. of spines cS VII/VIII	6	10	7	6–8	6–8
Anal lobe length	55	177	87	125–140	117–137
No. of fringe setae	33	60	11	33–42	30–32
Fringe length	275	320	50	310–350	300