Saetheria reissi Jackson, 1977

Orel, Oksana V., 2014, To systematics of the genus Saetheria Jackson (Diptera, Chironomidae) from the Russian Far East, Zootaxa 3802 (1), pp. 65-74 : 66-69

Saetheria reissi Jackson, 1977

( Figs 1–13 )

Saetheria reissi Jackson, 1977: 1354 , fig. 32; Ashe & Cranston 1990: 310; Langton 1991: 1192, fig. 111; Saether et al. 2000: 69; Zorina 2003: 223, figs 22–24; Makarchenko et al. 2005: 413; Zorina 2006: 426, fig. 292, 8–9, fig. 394, 7–10; Langton & Pinder 2007: 190, fig. 231A; Yan et al. 2011: 35 .

Paracladopelma kisopediformis Sasa, Kondo, 1993: 98 , fig. 7.1; Ree 2009: 243, fig. 1. Syn. nov. Saetheria tylus (Townes) , Zorina 2000: 110 (misidentification).

Material examined. PRIMORYE TERRITORY: male, Nadezhdenky Region, Razdol’naya River, 31.05.1990, Vshivkova T.S.; 1 male, same data, 0 2.06.1990, Vshivkova T.S.; male, Khankaisky Region, Khanka Lake basin, Kommisarovka River, 17.06.1999, Makarchenko E.A.; 2 males, 2 larvae, Khasansky Region, Barabashevka River, 0 1.06.2002, Teslenko V.A.; P-male, same data, 0 4.06.2002, Teslenko V.A.; male, larva, same data, 0 1.06.2003, Makarchenko E.A.; larva, same data, 12.05.2004, Makarcheko E.A.; male, Khasansky Region, Izvestkovaya River, 31.05.2003, Lubaretz V.; larva, Partizansraya River about Peretino Vallage, 29.05.2004, Vshivkova T.S.; male, Terneisky Region, Samarga River, 0 7.08.2006, Zorina O.V.; KHABAROVSK TERRITORY: Р-male, Chegdomynsky Region, Chegdomyn River, 13.07.2003, Tiunova T.M.; larva, Urgal River, 18.07.2003, Tiunova T.M. AMUR TERRITORY: P-male, 2 larvae, Zeya River basin, Ulunga River near Aprel’sky Village, 20.07.2008, Kotzuk D.B. SAKHALIN REGION: male, Otchepukha River about Lesnoe Village, 0 3.07.1985, Makarchenko E.A.; MAGADAN TERRITORY: P-male, pupal exuviae; Tauy River; 17.07.2001, Kocharina C.; SOKHA REPUBLIC (YAKUTIA): P-male with larval exuviae, Aldan River basin, Chul’man River, 25.07.2006, Makarchenko E.A.

Diagnostic characters. The male of S. reissi Jackson is distinguished by the following combination of features: wing length 2.1–2.4 mm; AR 1.81–2.10; small frontal tubercles always present; anal point spoon-shaped; superior volsella consist of bare dorsal lobe with a finger-shaped sclerotized projection and triangular ventral lobe covered with microtrichia and bearing 1 strong apical seta and 1 weaker median seta; gonostylus narrowed in middle. The pupa with 1 L seta on segment I, with 2–3 L setae on segments II–IV, with weak median shagreen on sternite IV, with median shagreen on tergite V. The larva with setae SI seta-like, SII broadly blade-like, SIII hairlike; AR 1.13–1.26; segment 2 of antenna 5–7 µm long, apically with the blade reaches the apex of the segment 5; premandible with 3 large distal teeth and 1 small proximal tooth; seta subdentalis a wide blade-like; mentum with broad triangular or round median tooth and 6 pair of lateral teeth; third pair lateral teeth below the remaining teeth.

Male (n=7). Total length 3.2–3.8 mm. Wing length 2.1–2.4 mm. Total length / wing length 1.52–1.76.

Colouration. Pedicel of antenna, mesonotal stripes and postnotum yellowish brown, ground colour and scutellum pale yellowish. Abdomen yellowish or yellowish-brown. Fore legs yellowish with brown distal end of femora, proximal third and distal end of tibia, ta1–5 gradually darkened toward ends, tibiae sometimes brown. Mid and hind legs yellowish, ta1–5 gradually darkened toward ends.

Head. Frontal tubercles small (3.4–10.2 µm long, 3.4–6.8 µm wide). Antenna 944–1080 µm long; ultimate flagellomere 608–720 µm long; AR 1.81–2.10. Verticals 12–19. Clypeus with 8–10 setae. Maxillary palp 435–510 µm long; length of palpomeres 2–5 (in µm): 34–44, 109–126, 116–139, 170–204. Head width / palp length 0.42–0.43; antenna length / palp length 2.12–2.28.

Thorax chaetotaxy. Antepronotals 1–3, acrostichals 6–11, dorsocentrals 6–13, supraalar 1–2, prealars 2–3. Scutellum with 5–9 setae.

Wing 0.51–0.60 mm wide. Veins R with 0–7 setae, R4+5 with 1–2 setae. Squama with 2–7 setae; brachiolum with 1–2 setae. VR 1.19–1.25.

Legs. Spurs of middle tibia 24–27 µm, of hind tibia 27–31 and 34 µm long. Lengths and proportions of legs as in Table 1 .

Hypopygium ( Figs 1–2 ). Laterosternite IX with 1–4 strong setae. Anal point spoon-shaped (length 54–61 µm, width 14–17 µm) at the base with 2–4 strong medial and 4–7 weak lateral setae. Gonocoxite 112–126 µm long, with 3–4 setae on inner margin. Transverse sternapodeme 68–82 µm wide. Phallapodeme 85–92 µm long. Superior volsella triangular (54–68 µm long and 14–17 µm wide in the base) composed of dorsal and ventral lobes. Dorsal lobe bare with a finger-shaped sclerotized projection (14–20 µm long), ventral lobe covered with microtrichia and bearing 1 strong apical seta (34–37 µm long) and 1 weaker seta (17–20 µm long) on middle. Inferior volsella with rounded apical part and covered with microtrichia. Gonostylus (147–170 µm long, 24–31 µm wide) narrowed in middle, apically round. HR 0.66–0.80.

Pupa (n=5, males). Cephalothorax ( Figs 3–4 ). Cephalic tubercle conical (20–31 µm long, 34–51 µm wide) with apical spine; frontal setae 68–109 µm long ( Fig. 3 ). Base of thoracic horn oval form (34 µm long, 17 µm wide). Lamelliform precorneals 2 (1st 170 µm long, 2nd 150–160 µm long), lamelliform antepronotals 2 (1 median 119–122 µm long and 1 lateral 290 µm long), dorsocentrals 4 (Dc1 34–54 µm long, Dc2 85–202 µm long, Dc3 41–61 µm long, Dc4 41–51 µm long); distance between Dc1 and Dc2 41–61 µm, Dc2 and Dc3 150–180 µm, Dc3 and Dc 4 10–14 µm ( Fig. 4 ).

Abdomen ( Figs 5–7 ) 2.2–2.4 mm long. Tergites I–III, VIII without shagreen. Hook row 153–204 µm long, with 44–50 spines. Tergites III–V on posterior margin with transverse band of strong dark spines distributed in 2–4 rows (tergite III with 47–62 spines, IV with 50–70 spines, V with 51–75 spines), tergite VI with weaker spines. Tergite IV with pair of anterolateral patches of shagreen ( Fig. 5 ), sometimes present weak median shagreen ( Fig. 6 ). Tergites V–VII with shagreen in a T-shaped ( Fig. 7 ), sometimes tergite V with pair anterolateral patches of spines and median spines ( Fig. 5 ) Sternite IV with median shagreen. Sternite V with or without posterolateral spines. Segment I with 1 L seta, segments II–IV with 2–3 L seta, V–VIII with 4 LS setae. Anal lobe with 28–40 lamelliform setae. Length of anal lobe 177–221 µm, width 187–279 µm. ALR 0.79–1.0.

Fourth instar larva (n=5). Green or greenish yellow (in formaldehyde).

Head. Yellowish, 0.3 mm long, 0.2 mm wide Antenna 102–122 µm long, length of segments (in µm): 58–78, 5.1–6.8, 24–31, 5.1, 6.8, 5.1 ( Fig. 8 ). AR 1.13–1.26. Basal segment with ring organ in proximal 1/4; distance from ring organ to base of antenna 17 µm; ROR 4.0–5.7. Blade 34–41 µm long, seated apically on segment 2, reaches the apex of the segment 5; accessory blade 20–27 µm. Lauterborn organ 3.4 µm long. Style 10 µm long. Seta SI seta-like 24 µm long, SII broadly blade-like 41 µm long, SIII hair-like 17 µm long, SIVa 3-segmented 10 µm long and SIVb 10 µm long. Labral lamella absent. Premandible 54 µm long, with 3 large apical teeth and 1 small proximal tooth; premandibular brush well developed. Pecten epipharyngis triangular, 10 µm long ( Fig. 9 ). Mandible 75–88 µm long, 41 µm wide, with apical (14 µm long) tooth and 2 brown inner teeth; seta subdentalis a wide blade-like 20–24 µm long; pecten mandibularis consist of 5 lamellae ( Fig. 10 ). Maxillary palp 20 µm long, 12–14 µm wide; distance from ring organ to base of maxillary palp 7–10 µm; ROR 2–3 ( Fig. 11 ). Mentum (61–68 µm wide) with brownish median tooth and 6 pair of lateral teeth. Median tooth (17–20 µm wide) triangular or round form; third lateral tooth below the remaining teeth ( Figs 12–13 ). Ventromental plate 51–58 µm wide, 37–41 µm high; number of striae 21; distance between ventromental plates 31–34 µm. VmPR 1.25–1.55. VmPSR 1.5–1.9.

Body. Posterior parapod with 17 yellow simple claws. Anal tubules conical, upper pair 85–102 µm long, bottom pair 102–119 µm long. Procercus 24 µm long, with 8 simple anal setae.

Remarks. The male of S. reissi Jackson is very similar to S. tylus (Townes) in the shape of the hypopygium, but can be separated by a larger body size (TL 3.2–3.8 mm), superior volsella roughly triangular form, gonostylus narrowed in middle. Whereas, the male of S. tylus has total length 2.30–3.18 mm, superior volsella an elongated foot-shaped, gonostylus narrowed in the proximal third ( Townes 1945; Jackson 1977; Sasa 1989; Sasa & Tanaka 2001; Kobayashi 2007). The Russian far eastern specimens of S. reissi are different by larger body size from its found in the Irkutsk Territory (original description), Japan, and Korea ( Jackson 1977; Sasa & Kondo 1993; Ree 2009). The pupa of S. reissi is also similar to S. tylus , but can be separated by the presence of 1 L seta on segment I, 2–3 L setae on segments II–IV, median shagreen on tergite V and on sternite IV. While, the pupa of S. tylus characterized by the absence of L setae on segment I, median shagreen on tergite V and sternite IV, and the presence of only 2 L setae on segments II–IV ( Jackson 1977; Saether 1983; Pinder & Reiss 1986). According to Langton (1991) pupa of S. reissi has not shagreen on tergites IV–V and 1 L seta on segment I. Whereas pupae from our material are characterized by the presence of shagreen on tergites IV–V and 1 L seta on segment I. The larva also is very close to S. tylus , but can be easily separated by the presence of well developed premandibular brush, the blade of antenna reaches the apex of the segment 5. Whereas, the larva of S. tylus has not premandibular brush, the blade of antenna reaches of middle of the segment 5 ( Jackson 1977). The larva of Chironominae genuinae № 9 described by Lipina (1926) from Oka River has 3 large teeth in the apical part and a large tooth in middle of premandible, and seta subdentalis a narrow blade-like. The larvae of S. reissi in our material with 3 large apical teeth and 1 small proximal tooth and seta subdentalis a wide blade-like.

Paracladopelma kisopediformis Sasa, Kondo, 1993 syn. nov. was described based on adult male from Japan, Kiso River and redescribed from Korea ( Ree 2009). This species is currently regarded as a junior synonym of S. tylus ( Kobayashi 2007) . Unfortunately, we have not examined the holotype this species. But thanks to an electronic database of type specimens held by National Museum of Nature and Science was possible to view hypopygium of the holotype of the species. On digital photo the male have a roughly triangular form of superior volsella with two setae different length, which is characteristic for S. reissi (http://www. type.kahaku.go.jp/TypeDB/typedb_pub). Frontal tubercles present as S. reissi and S. tylus . Therefore, we believe that Paracladopelma kisopediformis Sasa, Kondo, 1993 is a junior synonym of S. reissi .

Distribution. Saetheria reissi Jackson is quite widespread in the West Europen ( Saether & Spies 2004). This species was so far reported from North Korea and Japan ( Sasa & Kondo 1993; Ree 2009; Saether et al. 2000). In Russian S. reissi is known from Angara River near Irkutsk Townes by original description ( Jackson 1977). This species is widespread in Russian Far East: Primorye, Khabarovsk and Amur Territories, Magadan and Sakhalin Regions, Sokha Republic (Yakutia) ( Makarchenko et al. 2005).

Figures

FIGURES 1 – 13. Saetheria reissi Jackson adult male (1 – 2), pupa (3 – 7) and larva (8 – 13). 1 — hypopygium, dorsal view; 2 — superior volsella, ventral view; 3 — frontal tubercle; 4 — thorax, lateral view; 5 — tergites I – IX; 6 — tergite IV; 7 — tergite V; 8 — antenna, 9 — labro-epipharyngeal region; 10 — mandible; 11 — maxilla; 12 — mentum; 13 — mentum and ventromental plates. Scale bar 50 µm.

Tables

TABLE 1. Lengths (in µm) and proportions of legs of Saetheria reissi Jackson, male (n = 7).

	fe	ti	ta1	ta2	ta3	ta4	ta5
p1	672–798	462–567	798–1008	420–546	294–378	189–231	105–126
p2	630–777	272–588	294–336	168–210	126–147	84	63
p3	861–1134	735–903	462–546	273–336	231–273	126–147	105