Stempellinella reissi Casas and Vilchez-Quero

Ekrem, Torbjørn, 2007, A taxonomic revision of the genus Stempellinella (Diptera: Chironomidae), Journal of Natural History 41 (21 - 24), pp. 1367-1465 : 1432-1435

publication ID	https://doi.org/ 10.1080/00222930701437360
persistent identifier	https://treatment.plazi.org/id/CD7F7062-6B4F-FFC6-FFDB-00FE813FFAD6
treatment provided by	Felipe
scientific name	Stempellinella reissi Casas and Vilchez-Quero
status

Treatment

Stempellinella reissi Casas and Vilchez-Quero View in CoL

Stempellinella reissi Casas and Vilches-Quero 1991, p 116 View in CoL . Holotype: P(„) (DBUA) Spain, Andalucia, Sierra Nevada, near Pradollano, Monachil stream, 1960 m a.s.l., 28 August 1987, J. Casas [examined]. Paratypes: 1 P „ [examined] and 1 Pex [not examined] as holotype except 2100 m a.s.l., 2 September 1986.

Additional material examined

France ( PHL): 1 P(♀), 3 P(„), eastern Pyrenees , Tech, 8 June 2000, J. Moubayed .

Diagnostic characters

Stempellinella reissi can be separated from other Stempellinella species by the following combination of characters: adult male with AR about 0.7; frontal tubercles large, conical; anal point with several (11–12) small spinulae between v-shaped anal point crests; four or five strong median tergite setae placed far from anal point; superior volsella strongly bent medially, square distally; median volsella short, stout, without microtrichiae, with fan of simple and pectinate lamellae. Adult female with AR 0.31; vaginal floor large, concave, covering about half of vaginal opening in ventral view; spermathecal ducts longer than notum and rami combined; seminal capsules as wide as length of notum; rami and notum equally long, combined shorter than 100 Mm; more than 30 setae on sternite VIII, no setae on vaginal floor. Pupa with well-developed, conical cephalic tubercles; frontal apotome with some large granulation; thoracic horn long and thin with numerous small chaetae scattered on most of horn; anterior precorneal somewhat shorter than median and posterior precorneals; thorax quite smooth; dorsocentrals short, about 30 Mm; anal lobe with 10–14 taeniae.

Redescription

Adult male (n 5 5, unless otherwise stated). Total length 1.7–1.9, 1.8 (n 53) mm; wing length not measurable.

Colour: head pale brown with dark pedicels and eyes; thorax with pale brown ground colour, dark brown scutal stripes, brown postnotum, preepisternum, and median anepisternum, scutellum pale, halteres pale; abdomen and legs pale brown.

Head: eyes without dorsomedian elongation; frontal tubercle large, conical, 9–15, 12 (n 53) Mm long; antenna ( Figure 23A View Figure 23 ) with 13 flagellomeres of which only 10 are easily discernible; AR (on 10 flagellomeres) 0.62–0.78, 0.70 (n 53); lengths of palpomeres (in Mm, n 54): 30–36, 32; 36–48, 43; 114–120, 116; 105–120, 113; 144–168, 154 (n 53). Clypeus about 25 Mm long with 10 setae; tentorium ca 90 Mm long, 20 Mm wide; three inner verticals, three outer verticals, two postorbitals (n 52).

Thorax (n 53): scutal tubercle absent; acrostichals 14–16, 15; dorsocentrals 8–9; humerals 0–1; prealars 1; scutellars 6–7; halterals 11–13.

Wing: not measurable or figurable since only pharate males were available for examination.

Legs ( Figure 23B View Figure 23 ): fore tibia with 15 Mm long spur; mid and hind tibiae with wellseparated, 10–12 Mm long combs, one mid and one hind tibial comb with 27–30 (n 52) Mm long spur, one mid hind tibial comb with one tooth slightly longer than rest; mid tarsus 1 without sensilla chaetica; pulvilli absent. Lengths and ratios of leg segments in Table III.

Hypopygium ( Figure 23C, D View Figure 23 ): anal tergite 90–110 (n 52) Mm long with transverse anal tergite band; four or five median tergite setae, placed far from anal point base, one lateral seta, 20–26 (n 52) apical setae; anal point 37 Mm long, basally 12 Mm broad with welldeveloped crests, distally thinner, but apex slightly thicker and blunt; 11–12 small spinulae and few microtrichia between crests on anal point; microtrichia-free areas absent at base of anal point. Gonocoxite 85–97 (n 52) Mm long; gonostylus 60–63 (n 52) Mm long; HR 1.42– 1.54. Superior volsella strongly bent mediad, rather rectangular distally, with four or five dorsal and two median setae on setiger, superior volsella otherwise bare; digitus absent; median volsella very short and stout, 15 Mm long, medially directed, stem simple, bare, with fan of simple 18–20 Mm long and some shorter, pectinate lamellae; inferior volsella ca 50 Mm long, broad, with several distal setae, dorsal surface without microtrichia.

Adult female (n 5 1). Total length 2.0 mm; wing length not measurable.

Colour: as male, but paler.

Head: as male, except cephalic tubercles not observable; antenna ( Figure 23E View Figure 23 ) with five flagellomeres, ultimate flagellomere ca 55 Mm long, AR 0.31; palpomeres not measurable. Clypeus with nine setae.

Thorax: acrostichals 13; dorsocentrals 8; humerals, prealars, scutellars, and halterals not observable.

Wing: as male, not measurable.

Legs: as male.

Genitalia ( Figure 23F View Figure 23 ): tergite IX semicircular, about 50 Mm long; sternite VIII with 36 setae, of which none are placed on vaginal floor; vaginal floor large, concave, covering about half of vaginal opening ventrally; gonapophysis VIII single lobe with long posteromedially directed microtrichia; gonocoxapodeme slightly curved; coxosternapodeme well developed with obvious anterior and posterior lobes. Notum including rami 87 Mm long, notum alone ca 45 Mm long. Seminal capsules ovoid, diameter 50 Mm with 163 Mm long spermathecal ducts. Postgenital plate triangular. Cercus 50 Mm long.

Pupa (n 5 5, unless otherwise stated). Total length 1.9–2.3, 2.0 mm; abdomen 1.4–1.7, 1.5 mm long. Colour of pupal exuviae: thorax pale brown with triangular pigment-free area on both sides of median suture ( Figure 24B View Figure 24 ); abdomen rather transparent with darker lateral margins on abdominal segments VII – VIII and anal lobe.

Cephalothorax ( Figure 24A, B View Figure 24 ): cephalic tubercle well developed, broad conical, 25–30, 27 Mm long; frontal setae taeniate, ca 125 Mm long; pedicel sheath tubercle absent; frontal apotome with coarse granulation. Thoracic horn 250–425, 313 (n 54) Mm long, 25–30, 27 Mm wide with 4–5 Mm long chaetae scattered on almost whole length; precorneals taeniate, arranged in a triangle on obvious mound, anterior seta ca 110 Mm long, median and posterior setae ca 130–160 Mm long; median antepronotal taeniate, two lateral antepronotals: one taeniate, one sensillum basiconicum; two pairs of fine dorsocentrals, anterior pair 25–35 Mm long. Thorax smooth except for few stronger granules present along median suture line. Prealar tubercle well developed, wide; nose of wing sheath well developed.

Abdomen ( Figure 24C View Figure 24 ): TII with large rectangular, median point patches which start anterior to seta D1; hook row 55–75, 63 Mm wide with 24–34, 29 hooks. TIII – VI with large, rectangular point patches; TVII without armament; TVII –IX with anterolateral patches of shagreen. Segment II with pedes spurii B; segment IV with pedes spurii A. Segment II with 3 D, 1 V, 3 L setae; segment III with 3–4 D, 2 V, 3 simple L setae; segment IV with 3 D, 2– 3 V, 3 simple L setae; segment V with 2–4 D, 2–3 V, 3 taeniate L setae; segment VI with 2 D, 3 V, 4 taeniate L setae, segment VII with 3 D, 3 V, 4 taeniate L setae, segment VIII with 1 D, 1 semi-taeniate V, 3 taeniate L setae; segment IX with 1 D seta on anal lobe, 8–14, 11 taeniate setae in anal fringe. One pair of O-setae present anteriorly on tergites II – V and anterolaterally on sternites II – VIII. Pleurae III and IV with scattered, weak shagreen. Posterolateral spur on segment VIII well developed.

Larva. Unknown.

Remarks

Stempellinella reissi View in CoL has been recorded from the Sierra Nevada in Spain and at the river Tech in the eastern Pyrenees, France, and probably has a restricted distribution to high elevation areas in central and southern Europe (see Casas and Vilches-Quero 1991 for additional information on the type locality). The males of this species can easily be separated from all other Stempellinella species by its characteristic median volsella which is quite similar to the median volsella seen in the genus Zavrelia View in CoL . Bare eyes and a transverse median tergite band are, however, characteristics for species in Stempellinella View in CoL . The pupa of S. reissi View in CoL keys to the genus Zavrelia View in CoL in the key to the Chironominae View in CoL of the Holarctic region ( Pinder and Reiss 1986), but can be separated from all known Zavrelia species by the coarsely granulose frontal apotome and only scattered shagreen on the pleurae (pleurae in Zavrelia View in CoL have dense shagreenation with points in rows).