Xenochironomus xenolabis Kieffer 1916
Creators: name: Fusari, Lívia Maria
name: Roque, Fabio De Oliveira
name: Hamada, Neusa
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Chironomidae
Xenochironomus
Xenochironomus xenolabis

description: Xenochironomus xenolabis (Kieffer, 1916)
Chironomus xenolabis Kieffer in Thienemann and Kieffer 1916: 526.
Xenochironomus xenolabis (Kieffer, 1916): Townes 1945: 92; Pinder and Reiss 1983: 348, fig. 10.80; Pinder and Reiss 1986: 360, fig. 10.84; Cranston et al. 1989: 423, fig. 10.73; Spies and Reiss 1996: 74.
Chironomus rousseaui Gotghebuer 1921: 148.
Tendipes (Xenochironomus) xenolabis (Kieffer): Kruseman 1933: 178–179.
Chironomus (Xenochironomus) xenolabis (Kieffer): Johannsen 1938: 46.
Xenochironomus (X.) xenolabis (Kieffer): Saether 1977: 171, fig. 83A.
Material examined. BRAZIL, São Paulo state, São Carlos, Parque Ecológico de São Carlos, 21°59’S 47°52’W, vi.2006, 4 males, leg.: Fusari, L. M. São Paulo state, São Carlos, UFSCar, Fazzari Stream, vii.2007, 3 males, leg.: Fusari, L. M. São Paulo state, São Carlos, UFSCar, Fazzari Stream, vii.2007, 1 female with pupal exuviae, 2 females, leg.: Fusari, L. M. CANADA, Ottawa, Ont. Ottawa River. 21.vii.1980. 1male, coll. and leg.: F. Reiss (ZSM). Ontario, Saint Lawrence National Islands, Gordon River, 7. vii.1976, 1 male, leg.: Roussel M. E. (ZSM). ITALY, Pallanza, Lago Maggiore, 3.viii.1965. 2 males, coll. and leg.: Reiss F. (ZSM). Lago de Garda, 23.viii.1966. 1 male, coll. and leg.: F. Reiss. Only the genitalia mounted. (ZSM). PANAMA: Barro Colorado Island, Nemesis, 2. iii.1986, 1 male, coll.: F. Reiss. leg.: Malicky, H. (ZSM).
Diagnosis. Xenochironomus xenolabis can be separated from other species in the genus by the following characters: male, apex of the anal point not surpassing the apex of the inferior volsella, median setae of the anal tergite distributed in one area, superior volsella distint and inferior volsella with plumose setae; pupa, tergites II–V with two areas of black shagreen on the median region; larva, labral sclerite 1 divided into 2 plates and mentum with an odd number of teeth.
Comments. The larvae of X. xenolabis recorded from southeastern Brazil were collected in the freshwater sponge Radiospongilla amazonensis Volkmer-Ribeiro et Maciel, 1983. Some larvae were kept alive with the sponge in aerated tanks to obtain pupae and adults. Paired adults were kept alive in individual bottles to allow the association of pupal exuviae and adult emergence.
Xenochironomus alaidae sp. n.
Type material. Holotype: BRAZIL, Rio Grande do Sul state, Bossoroca, Barra do Angico, Piratinim River, 28°32’06.2”S 54°57’29.9”W, 28.xii.2007, adult male, leg.: Pes, A. M. O.
Etymology. In honor of Dr. Alaide Fonseca Gessner for her contribution to knowledge of benthic macroinvertebrate biodiversity and for encouragement during this study.
Diagnosis. Xenochironomus alaidae can be distinguished from other species in the genus by the following characteristics: male, apex of anal point surpassing or as long as the inferior volsella and presence of setae on latero-posterior tergite IX.
Description. Male (n = 1)
Color. Light brown. Thorax with scutum brown. Apices of tarsomere 2–5 dark brown.
Total length 4.54 mm. Wing length 2.40 mm, width 0.74 mm. Total length/wing length 1.88. Wing length/ profemur length ratio 5.22.
Head. AR 1.64. Apical flagellomere 550 Μm long. Temporals 11. Clypeus with 13 setae. Palpomere lengths 1– 2 (in µm): 43; 43.
Thorax. Ac 13; Dc 15; Pa 7; Scts 11.
Wing. VR 1.08. Brachiolum 2 setae. R with 29 setae, R1 with 28 setae and R4+5 with 37 setae; remaining veins bare. Squama with 15 setae.
Legs. Lengths (µm) and proportions of leg segments as in Table 6.
Hypopygium (Fig. 7 A–C). Laterosternite IX with 6 setae. Anal tergite with 14 setae divided into two lobes. Anal point 54 Μm long, 33 Μm wide at the base. Phallapodeme 98 Μm long; transverse sternapodeme 106 Μm long. Superior volsella 89 Μm long, 21 Μm wide at the base. Inferior volsella 92 Μm long, 29 Μm wide at the base and 18 Μm wide at the apex. Gonocoxite 208 Μm long. Gonostylus 137 Μm long. HR 1.52. HV 3.30.
Female and immatures: unknown.
Comments. The adults of X. alaidae sp. n. were collected in light traps located over an area of the river with a large concentration of the sponges Oncosclera jewelli (Volkmer, 1963) and Oncosclera sp.
Xenochironomus amazonensis sp. n.
Type material. Holotype: BRAZIL, Amazonas state, near the mouth of the Cuieiras River, 4.ii.1962, light trap, 1 male, leg.: Fittkau, E. J. (ZSM). Paratypes: 1 male, same data as holotype. Amazonas state, Parintins, light trap, 1 male, leg.: Sioli-Sattler (ZSM). Amazonas state, Rio Negro, light trap, 1 male, only genitalia mounted (ZSM).
Etymology. The specific name refers to the locality where the holotype was collected.
Diagnosis. Xenochironomus amazonensis can be separated from other species in the genus by the following characteristics: male, tergite IX with small setae; apex of the anal point surpassing the margin of the inferior volsella; inferior volsella broad, with short curved setae and gonostylus extending from the median to the distal region.
Description. Male (n = 1–3)
Color. Thorax and abdomen brown. Femur and tibia brown, apex of tarsomeres 1–5 dark brown.
Total length 1.7–1.9 mm. Wing length 0.5 mm. Wing length/profemur length ratio 1.9–2.0.
Head. AR 3.0–3.6. Apical flagellomere 780–790 Μm long. Temporals 10–11. Clypeus with 11–20 setae. Palpomere lengths 1–5 (in µm): 35–50, 31–35, 57–142, 125–132, 120–177.
Thorax. Ac 7–12; Dc 9–10; Pa 4–5; Scts 4–5.
Wing. VR 1.1–1.2. Brachiolum with 2 setae. R with 15 setae, setae of veins R1 and R4+5 unmeasured, remaining veins bare. Squama with 6–8 setae.
Legs. Length (µm) and proportions of leg segments as in Table 7.
Abdomen. In poor state of conservation.
Hypopygium. (Fig. 8 A–B). Laterosternite IX with 3 setae. Anal tergite with 13 setae in median region. Anal point 50–72 Μm long; 37–52 Μm wide at the base, 25–42 µm wide at the apex. Phallapodeme 75 Μm long; transverse sternapodeme 42–50 Μm long. Superior volsella 22–27 Μm long, 27–30 Μm wide at the base. Inferior volsella 87–142 Μm long, 35–47 Μm wide at the base and 22–30 Μm wide at the apex. Gonocoxite 132–167 Μm long. Gonostylus 162–195 Μm long. HR 0.82–0.87.
Female and immatures: unknown.
Xenochironomus ethiopensis sp. n.
Type material. Holotype: ETHIOPIA, Bahar Daram, Tana-See, 26. i.1977, 1 male, leg.: Reichholf, J. (ZSM).
Etymology. The specific name refers to the country where the holotype was collected.
Diagnosis. Xenochironomus ethiopensis can be separated from other species in the genus by the following characteristics: male, apex of the anal point not surpassing the inferior volsella; superior volsella long, large, with the apex bent dorsally; inferior volsella long, large, robust, with few thin setae and slender gonostylus.
Description. Male (n = 1)
Color. Thorax with pronotum brown. Abdomen brown. Femur, tibia and tarsomere 1–5 brown.
Total length 4.88 mm. Wing length 2.5 mm, width 0.72 mm. Total length/wing length 1.9. Wing length/ profemur length ratio 2.3.
Head. AR 3.0. Apical flagellomere 920 Μm long. Temporals 9. Clypeus with 17 setae. Palpomere lengths 1–5 (in µm): 27, 37, 210, 165, 290.
Thorax. Ac 14; Dc 6; Scts7.
Wing. VR 1.1. Brachiolum with 2 setae. R with 16 setae, R1 with 8 setae, R4+5 with 11 setae, remaining veins bare. Squama with 8 setae.
Legs. Length (µm) and proportions of leg segments as in Table 8.
Hypopygium. (Fig. 9 A–B). Laterosternite IX with 2 setae. Anal tergite with 25 setae divided into two lobes. Anal point, 72 Μm long and 21 Μm wide at the base. Phallapodeme and transverse sternapodeme, not observable. Superior volsella 52 Μm long, 55 Μm wide at the base. Inferior volsella 155 Μm long, 47 Μm wide at the base and 60 Μm wide at the apex. Gonocoxite 160 Μm long. Gonostylus 252 Μm long. HR 0.63. HV 1.93.
Female and immatures: unknown.
Xenochironomus grini sp. n.
Type material. Holotype: BRAZIL, Pará state, Rurópolis,Tambor River, Grin Waterfall, (04°05’35”S 55°00’29”W) 28. x.2007, 1 male with pupal exuviae, leg.: Fusari, L. M., Hamada N. Paratypes: Amazonas, Presidente Figueiredo, BR 174, Km 121 (01°55’S 60°03’W), 04. v.2006, 1 male, leg.: Roque, F. O., Pes, A. M. O. 1 pupa with larval exuviae, 3 fourth-instar larvae, same data as holotype.
Etymology. In honor of the owner of the farm, Sr. Grin, where the Grin Waterfall is located and where the holotype was collected.
Diagnosis. Xenochironomus grini can be separated from other species in the genus by the following characteristics: male, apex of the anal point not surpassing the apex of the inferior volsella; setae on the median portion of the anal tergite divided into two areas; gonocoxite with setae as long as the gonostylus; gonostylus short and rounded; inferior volsella with short setae. Pupa, tergites II, IV–VII with anterior bands of black shagreen; sternites I and II without spines and prealar tubercle present. Larva, mentum with 12 teeth.
Description. Male (n = 1–2)
Color. Pale brown, with anterior thorax, scutum and pronotum dark brown. Legs uniformly light brown.
Total length 3.8–4.7 mm. Wing length 1.9–2.2 mm, width 0.5–0.6 mm. Total length/wing length 1.9–2.2. Wing length/profemur length ratio 2.1–2.2.
Head. AR 3.43–3.47. Apical flagellomere 840–920 Μm long. Temporals 11–21. Clypeus with 12–13 setae. Palpomere lengths 1–5 (in µm): 18–35; 30; 95–103; 110–115; 135–153.
Thorax. Ac 6; Dc 12; Pa 4–5; Scts 1.
Wing. VR 1.12–1.17. Brachiolum with 2–3 setae. R with 15–21 setae, R1 with 8 setae and R4+5 with 7 setae, remaining veins bare. Squama with 4–8 setae.
Legs. Length (µm) and proportions of leg segments as in Table 9.
Hypopygium. (Fig. 10 A–B). Laterosternite IX with 3 setae. Anal tergite with 23 setae divided into two lobes. Anal point 43–55 Μm long; 35–48 Μm wide at the base, 38 µm wide at the apex. Phallapodeme 85–90 Μm long; transverse sternapodeme 70–78 Μm long. Superior volsella 58–73 Μm long, 13–15 Μm wide at the base. Inferior volsella 103 Μm long, 20–25 Μm wide at the base and 18–23 Μm wide at the apex. Gonocoxite 150–165 Μm long. Gonostylus 103–138 Μm long. HR 1.20–1.46. HV 3.45–3.69.
Pupa (n = 1–2)
Total length 4.60–5.35 mm. Exuviae light brown.
Cephalothorax (Fig. 11 B). Frontal apotome with cephalic tubercles low, rounded and rough. Frontal setae 64– 92 µm long. Two antepronotal setae, 1 lateral, 108–143 µm long and 1 median, 54 µm long. Thoracic horn plumose. Basal ring elliptical, 35–44 µm in diameter. Median suture and dorsal region with granulations. Two precorneal and four dorsocentral setae, Dc1 55 µm long, Dc2 63 µm long, Dc3 60 µm long, Dc4 72 µm long, with distances Dc1–Dc2, Dc2–Dc3, Dc3–Dc4 (µm): 45–67; 195–209; 21–53. Prealar tubercle absent.
Abdomen (Fig. 11 A). Tergite I bare. Tergites II–VIII with shagreen on the middle region. Tergite II with anterior, posterior and transverse bands of dark shagreen. Tergite III with posterior transverse bands of shagreen. Anterior region of tergites IV–VI with two groups of black spines surrounding the median region. Tergites VII and VIII with shagreen on median region. Sternites I and II without spines. Tergite II with continuous row of hooks 488–417 µm long. Pedes spurii B weakly developed in segment II. Pedes spurii A present in segment IV. Posterior margin of segments V and VI with small thin spines. Segment I with 1 LS, II–V with 2 LS, VI–VII with 4 lateral taeniae, VIII with 5 lateral taeniae Anal lobe with small spines on middle region with complete fringe and over 50 setae on each side.
Fourth instar larva (n = 1–4)
Head. Width 0.29–0.38 mm, length 0.39–0.44 mm. IC 0.76–0.87. Labral sclerite 1 undivided; labral sclerite 2 with rostrum anterior. Pecten epipharyngis trifid with denticles distal. Premandible not observed. Antenna 117–129 µm long, with 5 segments (Fig. 11 C); basal segment 61–70 µm long; AR 1.09–1.17, ring organ near the base of antenna, blade shorter than flagellum, 54–58 µm long. Accessory blade short. Mandible 85–137 µm long, with dark apex and three inner teeth; dorsal tooth absent; seta subdentalis long (Fig. 11 D). Mentum 84–90 µm wide, with 12 dark teeth (Fig. 11 E); ventromental plates 91–105 µm wide; median plates separated by no more than the width of the median teeth. Setae submenti 66 µm long.
Abdomen reddish, 4.94–5.26 mm long. Anal tubules 149–203 µm long, without constriction. Procercus with 10–12 long anal setae.
Female: unknown.
Comments. Larvae of X. grini sp. n. were collected in Oncosclera navicella (Carter, 1881).
Xenochironomus martini sp. n.
Type material. Holotype: BRAZIL, Rio Grande do Sul state, Bossoroca, Barra do Angico, Piratinim River, (28°32’06.2”S 54°57’29.9”W), 28. xii.2007, 1 male, leg.: Pes, A. M. O.
Etymology. In honor of Dr. Jon Martin for his contribution to cytogenetic and molecular studies of Chironomidae and for providing specimens and information during this study.
Diagnosis. Xenochironomus martini can be distinguished from other species in the genus by the following characteristics: male, median setae on anal tergite divided into two areas; inferior volsella with several setae; superior volsella pediform and apex of inferior volsella spatulate.
Description. Male (n = 1)
Color. Light brown. Thorax with brown scutum. Tarsomere 2–5 dark brown.
Total length 3.74 mm. Wing length 1.75 mm, width 0.50 mm. Total length/wing length 2.14. Wing length/ profemur length ratio 2.24.
Head. AR 1.46. Apical flagellomere 572 Μm long. Clypeal and temporal setae not observed. Palpomere lengths 1–4 (in µm): 28; 44; 136; 109.
Thorax. Ac 23; Dc 10; Pa 5; Scts 10.
Wing. VR 1.14. Brachiolum 2 setae. R with 9 setae, R1 with 9 setae and R4+5 with 7 setae; remaining veins bare. Squama with 4 setae.
Legs. Length (µm) and proportions of leg segments as in Table 10.
Hypopygium (Fig. 12 A–D). Laterosternite IX with 5–6 setae. Anal tergite with 30 setae divided into two lobes. Anal point 48 Μm long; 25 Μm wide at the base. Phallapodeme 95 Μm long, transverse sternapodeme 62 m long. Superior volsella 75 Μm long, 11 Μm wide at the base. Inferior volsella 107 Μm long, 20 Μm wide at the base and 13 Μm wide at the apex. Gonocoxite 175 Μm long. Gonostylus 162 Μm long. HR 1.08. HV 3.54.
Female and immatures: unknown.
Comments: The adults of X. martini sp. n. were collected in light traps located over an area of the river with a large concentration of the sponges Oncosclera jewelli (Volkmer, 1963) and Oncosclera sp. Additional sampling in this area should be carried out to obtain immature specimens. In analyzing specimens from Australia it was observed that the adults of morphotype Xenochironomus “australian” (cited in Cranston 2000a) are similar to X. martini sp. n., but these specimens were not included in the type material because it would be necessary to examine the immature stages of both the new species and the morphotype from Australia, since some closely related species are similar in the adult stage but can be differentiated in the immature stages.
Xenochironomus mendesi sp. n.
Tzpe material. Holotype: BRAZIL, Rio Grande do Sul state, Jaquirana, Passo da Ilha, Tainhas River, (29°05’11”S 50°21’52”W), xi.2007, 1 male, leg.: Hamada, N. Paratypes: Goiás state, Alto Paraíso, Couros River, São Bento Farm, (14°09’36”S 47°35’37”W), 01–04. v.2007, 1 male with pupal and larval exuviae, 1 pupa with larval exuviae and 5 fourth-instar larvae, leg.: Fusari, L. M., Hamada. N.
Etymology. In honor of Dr. Humberto Fonseca Mendes for his assistance and encouragement during this study.
Diagnosis. Xenochironomus mendesi sp. n. can be separated from other species in the genus by the following characteristics: male, apex of the anal point surpassing or as long as the inferior volsella and setae of anal tergite divided into two areas. Pupa: sternites I and II with posterior bands of clear spines; pedes spurii A present in segment IV and prealar tubercle absent. Larva: labral sclerite 1 undivided; mentum with even number of teeth (16 teeth).
Description. Male (n = 1–2)
Color. Light brown. Thorax with scutum, scutellum and pronotum brown. Legs light brown, with apices of tarsomere 1 and tarsomere 2–5 dark brown.
Total length 5.67–5.73 mm. Wing length 2.60–3.00 mm, width 0.72–0.85 mm. Total length/wing length 1.90– 2.20. Wing length/profemur length ratio 2.70–3.05.
Head. AR 2.30–2.99. Apical flagellomere 880–950 Μm long. Temporals 9. Clypeus with 13 setae. Palpomere lengths 1–5 (in µm): 47; 63; 200; 160; 214.
Thorax. Ac approximately 19; Dc 11–14; Pa 5–7; Scts 10.
Wing. VR 1.04. Brachiolum 2 setae. R with 31 setae, R1 with 23 setae and R4+5 with 29 setae; remaining veins bare. Squama with 10 setae.
Legs. Length (µm) and proportions of leg segments as in Table 11.
Hypopygium. (Fig. 13 A–C). Laterosternite IX with 4–6 setae. Anal tergite with 22–29 setae, divided into two lobes. Anal point 53–73 Μm long and 72–90 Μm wide at the base. Phallapodeme 89–107 Μm long; transverse sternapodeme 80–100 Μm long. Superior volsella 80–89 Μm long, 12–13 Μm wide at the base. Inferior volsella 136–139 Μm long, 25–36 Μm wide at the base and 15–18 Μm wide at the apex. Gonocoxite 211–235 Μm long. Gonostylus 190–223 Μm long. HR 1.05–1.11. HV 2.54–3.01.
Pupa (n = 1–2)
Total length 5.37–6.57 mm. Exuviae light brown.
Cephalothorax. Frontal apotome with cephalic tubercles low, rounded and rough. Frontal setae 46–55 µm long. Two antepronotal setae (Fig. 14 C); 1 lateral seta 77–116 µm long and 1 median seta, 103–130 µm long. Thoracic horn plumose. Basal ring elliptical, diameter 38–49 µm. Median suture and dorsal region with granulations. Two precorneal and four dorsocentral setae, with distances Dc1–Dc2, Dc2–Dc3, Dc3–Dc4 (µm): 60–67; 156–243; 23–26. Prealar tubercle absent.
Abdomen (Fig. 14 A). Tergite I bare. Tergites II–VIII with shagreen on the middle region. Tergite II with anterior, posterior and transverse bands of dark shagreen. Tergite III with posterior transverse bands of shagreen. Anterior region of tergites IV–VI with two groups of black spines surrounding the median region. Tergites VII and VIII with shagreen on median region. Sternites I and II with posterior bands of clear spines (Fig. 14 B). Tergite II with continuous row of hooks 415–492 µm long. Pedes spurii B weakly developed in segment II. Pedes spurii A present in segment IV. Posterior margin of segments V and VI with small thin spines. Segment I with 1 LS, II with 4 LS, III–IV with 3 LS, V–VII with 4 lateral taeniae and VIII with 5 lateral taeniae. Anal lobe with small spines on middle region, with complete fringe and over 50 setae on each side.
Fourth-instar larva (n = 5–8)
Head. Width 0.23–0.36 mm, length 0.35–0.46 mm. IC 0.65–0.91. Labral sclerites 1 undivided, labral sclerites 2 with rostrum anterior. Pecten epipharyngis trifid with denticles distal. Premandible not observed. Antenna 113– 131 µm long, with 5 segments (Fig. 14 D); basal segment 54–62 µm long; AR 1.00–1.11, ring organ near the base of antenna; blade shorter than flagellum, 41–51 µm long. Accessory blade short. Mandible, 105–143 µm long, with dark apex and three inner teeth, dorsal tooth absent; seta subdentalis long (Fig. 14 E). Mentum 85–106 µm wide, with 16 dark teeth (Fig. 14 F); ventromental plates 83–101 µm wide; median plates separated by no more than the width of the median teeth. Setae submenti long 37–48 µm.
Abdomen reddish with 6.09–7.44 mm long. Anal tubules 366–368 µm long, without median constriction. Procercus with 8–10 long anal setae.
Female: unknown.
Comments. The larvae of X. mendesi sp. n. were collected in Metania spinata Carter, 1881.
description: Published as part of Fusari, Lívia Maria, Roque, Fabio De Oliveira & Hamada, Neusa, 2013, Review of Xenochironomus Kieffer, 1921 (Diptera: Chironomidae) with description of six new species, pp. 101-126 in Zootaxa 3646 (2) on pages 112-123, DOI: 10.11646/zootaxa.3646.2.1, http://zenodo.org/record/219502