Stenochironomus munteanpurin, Amora & Hamada & Pinho, 2018

Amora, Gizelle, Hamada, Neusa & Pinho, Iz. C., 2018, Stenochironomus munteanpurin sp. n., a new leaf-mining species from Brazil (Diptera: Chironomidae), Zootaxa 4382 (3), pp. 553-564 : 555-563

Stenochironomus munteanpurin sp. n.

( Figures 2A–B , 3A–G , 4A–C , 5A–E , 6A–E , 7A–H )

Type material. Holotype, BRAZIL, Rio de Janeiro, Itatiaia, Parque Nacional do Itatiaia, córrego Maromba, abaixo da cachoeira Véu de noiva, ponto #08 , 22° 25’ 38.6”S 44° 37’ 9.7”W, 03.v.15, reared from submerged leaf, 1 male with pupal and larval exuviae, leg. Hamada, N. & Cavalcante, J.M.C. ( INPA, slide-mounted in Euparal®) . Paratypes: 2 male with pupal and larval exuviae, same locality as holotype ( INPA, slide-mounted in Euparal®); 4 male with pupal exuvia, BRAZIL, Santa Catarina, Florianópolis, rio do Estaleiro, 27° 47’ 49”S 48° 33’ 28”W, 02.x.12, reared from submerged leaf, leg. Parise, A.G. ( INPA, slide-mounted in Euparal®); 1 male, BRAZIL, Santa Catarina, Florianópolis, rio do Estaleiro, 27° 47’ 49”S 48° 33’ 28”W, 02.x.12, Malaise, leg. Parise, A.G. ( INPA, slide-mounted in Euparal ®); 1 male with pupal exuvia, BRAZIL, Santa Catarina, Santo Amaro da Imperatriz, Serra do Tabuleiro , 27° 44’ 13.1”S 48° 48’ 59”W, 14.v.04, reared from Miconia cabucu Hoehne (Melastomataceae) submerged leaf, leg. Pinho, L.C. ( INPA, slide-mounted in Euparal®); 1 male with pupal exuviae and larval exuviae, BRAZIL, Santa Catarina, Santo Amaro da Imperatriz, Hotel Plaza - stream , 14.v.04, reared from M. cabucu submerged leaf, leg. Pinho, L.C. ( INPA, slide-mounted in Euparal®); 1 male, BRAZIL, Santa Catarina, Porto Belo, Refúgio do Estaleiro , 27° 06’ 58.7”S 48° 30’ 32.4”W, 26.iv.04, Light Trap, leg. Parise, A.G. ( INPA, slide-mounted in Euparal®); 1 male with pupal exuviae and larval exuviae, BRAZIL, Santa Catarina, Florianópolis , Unidade de Conservação Ambiental Desterro - UCAD, 27°31'17.3"S 48°30'18.1"W, 13.iii.2004, reared from leaves, leg. Pinho, L.C. ( INPA, slide-mounted in Euparal®); 3 male, Brazil, Santa Catarina, Reserva Biológica Marinha do Arvoredo, ponto #88 , 27° 17’ 35’’S 48° 21’ 59’’, 17.ii–9.iv.16, Malaise, leg. Pinho, L.C.; Amaral, A.P. & Vieira, P.A. ( INPA, slide-mounted in Euparal®); 1 male, BRAZIL, Acre, Mâncio Lima, PN Serra do Divisor, Pé da serra, Base IBAMA, Igarapé amor , 05.xi.2007, Malaise trap, leg. Calor, A.R. ( INPA, slide-mounted in Euparal®) ; 3 male, BRAZIL, Bahia, Camacan, Serra Bonita , Afluente do Rio Panelão , 15° 23’ 26”S 39° 33’ 58”W, iii.2009, Malaise 2 trap, leg. Calor, A.R.; Lecci, L.S.; Pinho, L.C. & Moretto, R.A. ( UFSC, slide-mounted in Euparal®) .

Etymology. The specific epithet munteanpurin means “midge of the leaf” (müntean = midge, mosquito; pürin = leaf) in Tukano language, spoken by the native Amazonian ethnic group Tukano. The name is to be regarded as a noun in apposition.

Diagnostic characters. The male imago can be distinguished from all other Stenochironomus species by: Male: TIX with more than 25 setae medially, phallapodeme curved anteriorly, volsella superior short and gonostylus tapering in apex, slightly curved down. Pupa: shagreens being in all TI, less number of hooklets in TII, TVII without shagreens and presence of shagreen in conjunctive III/IV and IV/V. Larva: can be distinguished by labral lamella arranged in two groups with one or two conical-shaped teeth, spicules of pecten epipharyngis arranged in a row, unequal and irregularly distributed sizes, SI bifurcated, SII pinnate, SIII pinnate setae and larval exuviae is compacted

Adult male (n= 6, except when otherwise stated).

Total length 4.00–4.59, 4.23 mm. Wing length 1.89–2.05, 2.00. Total length/ wing length 1.97–2.43, 2.11. Wing length/ length of profemur 1.40–1.87, 1.49.

General coloration: golden-yellow when alive or preserved in alcohol. Head: eyes metallic blue when alive or preserved in alcohol; antennal segments and setae golden-yellow. Thorax: two dark patches on the lateral vittae; postnotum with brown pigmentation near anterior margin. Legs: forefemur with two band, one light brown in median region and one dark-brown in distal region; foretibia with two brown band, one light brown in proximal region and one dark-brown in apex; fore ta1–ta3 yellowish with light-brown apex; fore ta4 with 2/3 light-brown apex; fore ta5 light-brown. Midleg and hindleg yellowish. Wing: clear without a medial light-brownish band. Abdomen: T II–IV with brown pigmentation restricted to posterior margin. TII with pigmentation divided into two parts ( Figs. 2A–B ; 3E).

Head ( Fig. 3A ). AR 1.30–1.45, 1.39. Thirteenth flagellomere 663–747, 709 µm long ( Fig. 3B ). Temporal setae 10–12, 11, extending to the posterior margin. Clypeus with 17–21, 19 setae. Tentorium 132–157, 150 µm long; 31– 36, 34 µm wide at sieve pore; 10–11, 11 µm wide at posterior tentorial pit. Stipes 136–191, 157(5) µm long; 8–11, 9 µm wide. Palpomere length (1–5 in µm): 22–48, 40; 49–64, 57; 140–159, 152(5); 107–120, 114(5); 134–191, 176(5).

Thorax ( Fig. 3C ). Acrostichals 14–21, 16; dorsocentrals 6–12, 9, in a single row; prealars 3–4, 4, in a single row. Scutellum with 11–21, 16 setae in two rows. Anterior edge of scutum angled in lateral aspect.

Wing ( Fig. 3D ). VR 1.12–1.79, 1.25. Brachiolum with 2 setae, with about 12–15 sensilla campaniformia. R with 30–39, 34 setae; R1 with 31–40, 36 setae; R4+5 with 40–64, 54 setae; M with 3–8, 5 setae; RM with 1–2, 1 setae; remaining veins bare. Squama with 3–6; 5 setae.

Legs ( Fig. 3F ). Scale of front tibia 34–50, 43 µm long; Spurs of middle tibia 22–33, 27 µm and 24–41, 31 µm long; spurs of hind tibia 25–35, 30 µm and 26–38, 32 µm long. Apex of fore tibia 56–82, 65 µm wide, mid tibia 56– 81, 66 µm wide, of hind tibia 65–79, 71 µm wide. Length (in µm) and proportion of legs as in Table 1.

Hypopygium ( Figs. 3G ; 4A–B). Anal point thin and straight in dorsal view, curved ventrally close to apex ( Fig. 4C ).; 64–73, 70 µm long; 11–19, 15 µm wide at base; 7–9, 7 µm wide at the midpoint; 5–9, 7 µm wide at apex. Tergite IX with 19–28, 25 setae. Laterosternite IX with 3–5, 4 setae. Phallapodeme curved anteriorly, 82–104, 94 µm long; transverse sternapodeme 31–48, 39 µm long. Gonocoxite 147–179, 163 µm long. Inferior volsella 95– 204, 175 µm long, with 5–7, 6 setae arranged in a regular form; superior volsella 36–50, 42 µm long, with 4–5, 4 setae. Gonostylus large at mid region and narrow at distal region; 121–158, 136 µm long. HR 0.93–1.39, 1.21; HV 0.25–0.36, 0.31.

Pupa (n= 6, except when otherwise stated) ( Fig. 5A–B ).

Total length 4.82–5.43, mm (n= 5). General coloration light brown, abdomen, laterally, brownish.

Cephalothorax ( Fig. 6E ). Frontal apotome not elongated; precorneal setae long and thin, with 186–230, 205(5) µm long. Dorsocentral (Dc) Dc 1 24–55, 38(5); Dc 2 28–43, 39(5); Dc 3 22–45, 32(5); Dc 4 18–39, 28(5) µm long, lamelliform. Distance between Dc1 and Dc2 0.33–0.46, 0.36 µm; between Dc2 and Dc3 199–255, 226 µm; between Dc3 and Dc4 0.34–0.46, 0.37 µm. Median suture granulose.

Abdomen ( Figs. 6A–D ). TI–TIII with large field of shagreen; TVI with field of shagreen, not extending until lateral margin, being thicker near the anterior margin; TV–TVI with field of shagreen medially, being thicker near the posterior margin. TVII with two field shagreen fine anterolateral; two patches medial fine shagreens, one in anterior and a posterior in the shape of inverted triangle, both separated by bare areas. TVIII–TIX with two field shagreens fine anterolateral. TII with a posterior row of small sized hooklets restricted to medial area of tergite, not divided medially, with 42–61; 48 hooklets; pedes spurii B absent. TIV with shagreen quadridentate in anterior margin. Conjunctive III/IV and IV/V with shagreen. Abdominal setation: SI with 0–1(2) L setae anterior; SII with 1–3(5) L setae, being two anterior and one posterior or only one anteriorly; SIII–SIV with 2–3 L setae, being two anterior and one posterior or one anterior and one posterior; SV with 3–4 LS setae, being two anterior and one posterior or two anterior and two posterior; SVI with 4–5 LS setae, being two anterior and two posterior or three anterior and two posterior; SVII with 4 LS setae, being two anterior and two posterior; SVIII with 5 LS setae regularly distributed. Spur on SVIII with 2–4 brownish teeth ( Figs. 5C–E ), being the median teeth greater than the others with 25–32, 27 µm long. Genital sac 129–315, 191 µm long and 90–254, 144 µm wide, not overreaching the posterior margin of the anal lobe. Anal lobe with 153–360, 243 µm long and 139–325, 213 µm wide; apex of anal lobe rounded, with fringe of about 45–71, 55 filaments.

4th instar larva (n= 5, except when otherwise stated).

Head. Head capsule 0.25–0.49, 0.34 mm. Antenna as in Figure 7A ; lengths of antennal segments (in µm): 41– 55, 51; 18–21, 19; 9–15, 11; 8–9, 9(4); 2–4, 3(4). Antennal blade 10–18, 14 µm long. Labrum as in Figure 7B . Labral lamellae arranged in two groups. Pecten epipharyngis with spicules short arranged linearly and irregularly along a wide margin. S1 bifurcated, 13–21, 18 µm long; S2 pinnate, 16–29, 22(4) µm long; S3 pinnate, 13–14, 14(3) µm long. Premandible 45–57, 49µm long. Mandible ( Fig. 7C ) 137–152, 143 µm long. Mentum concave ( Fig. 7E ) 89–103, 99 µm wide, with 10 blackish teeth, the four median teeth being fused, but in some specimens it is not possible to distinguish them; micropore located postero-laterally in relation to the setae submenti; ventromental plate with patches the small thorn on anterolateral margin ( Fig. 7F ). Base of dorsolateral strip originating at the midpoint of the dorsomedian strip. Labiohypopharynx ( Fig. 7D ) with ligular lobes rounded, with parallel-sided cleft between them.

Abdomen. Not measurable. Larval exuviae compacted ( Figs. 7G–H ).

Female unknown.

Notes on biology and ecology of the species. In Parque Nacional do Itatiaia (Rio de Janeiro), the mining leaves were collected in 3rd -order streams, water temperature of 14.4°C, pH of 7.1 and electrical conductivity of 7.1 µS/cm; the stream has clear water, boulders and sand bottom and preserved riparian vegetation. The mined leaves were collected in rapids areas in between the rocks.

Systematic remarks. In the male key of the Neotropical Stenochironomus ( Dantas et al. 2016) , S. munteanpurin sp. n. key to couplet 24 ( S. jubatus / S. quadrinotatus ). The patches of vittae and anterior portion of postnotum of S. munteanpurin sp. n. is similar a S. quadrinotatus Borkent, 1984 , however, the adult male of the new species can be distinguished by TIX with more than 25 setae medially, phallapodeme is curved anteriorly, superior volsella is short and gonostylus tapers at apex. In S. quadrinotatus the TIX has more than 35 setae medially, phallapodeme is not curved anteriorly, superior volsella short, narrow in apex and apex of gonostylus is rounded. The pupae of S. munteanpurin sp. n. show striking differences to the pupa of S. quadrinotatus . For example, S. munteanpurin sp. n., TI is covered with setae, shagreen present in the conjunctive III/IV and IV/V, and shagreen distributed medially in TVII, while in S. quadrinotatus all the above mentioned structures are absent. Moreover, the larvae of the S. munteanpurin sp. n. differ from the S. quadrinotatus mainly by labral lamella arranged in two groups with one or two conical-shaped teeth, spicules of pecten epipharyngis unequal and irregularly distributed sizes, SI bifurcated, SII and SIII pinnate setae and larval exuviae is compacted. While, in S. quadrinotatus labral lamella are arranged in two groups with two or three conical-shaped teeth, spicules of pecten epipharyngis equal in size and regularly distributed, SI pinnate, SII and SIII simple and larval exuviae free. Borkent (1984) proposed the subgenus S. ( Stenochironomus ) to include wood mining larvae species and S. ( Petalopholeus ) to leaf mining larvae species. According to the diagnose of S. ( Petalopholeus ), the pupae have TII with posterior row of hooklets restricted to medial portion and segments TVII and TVIII with at least some spicules. Although S. munteanpurim sp. n. larvae are leaf mining, its pupae have row of hooklets only in TII.

Figures

FIGURE 2. Male adult of Stenochironomus munteanpurin sp. n. A. Male adult, dorsal view.B. Male adult, lateral view.

FIGURE 3. Male adult of Stenochironomus munteanpurin sp. n. A. Head, frontal view. B. Antennae. C. Thorax, lateral view. D. Wing, left.E. Abdomen,dorsal view.F. Legs, from left to right, fore, mid and hindleg.G. Hypopygium, dorsal view.

FIGURE 5. Pupa of Stenochironomus munteanpurin sp. n. A. Dorsal view. B. Lateral view. C–E. Variation of the spur on T XIII.

FIGURE 6. Pupa of Stenochironomus munteanpurin sp. n. A–D.Abdomen in dorsal view. E. Frontal apotome.

FIGURE 7. Larva of Stenochironomus munteanpurin sp. n. A. Antenna. B. Labrum. C. Mandible. D. Labiohypopharynx. E. Mentum and ventromental plate. F. Small patches in ventromental plate. G. Larval exuviae, lateral view. H. Larval exuviae, dorsal view.

FIGURE4. Male adult of Stenochironomus munteanpurinsp. n. A. Hypopygium,dorsal view.B. Hypopygium with anal point and tergite IX removed, dorsal aspect to the left and ventral aspect to the right.C. Anal point, lateral view.