Ameletus camtschaticus Ulmer, 1927

Tiunova, Tatiana M., Semenchenko, Aleksandr A. & Velyaev, Oleg A., 2017, New species of Ameletus Eaton, 1885 from the Russian Far East with notes on Ameletus camtschaticus Ulmer 1927 (Ephemeroptera: Ameletidae), Zootaxa 4276 (2), pp. 151-176 : 167-174

Ameletus camtschaticus Ulmer, 1927

(Figs 59–78)

Ameletus camtschaticus Ulmer, 1927: 12 , figs 10–12 [description; male imago]; Sinitshenkova & Tshernova, 1976: 13, figs 3‒9 [complementary description; male subimago, larva]; Kluge, 2004: fig. 11A‒D [figures of male imago genitalia]; Kluge, 2007: 251 [short description of larva, male genitalia and egg];

Ameletus pilatus Sinitshenkova, 1981:73 , fig. 1 [description; larva]; Tshernova et al., 1986: 126, figs 57: 7–8 [key; male imago]; Kluge, 1995: 10 [types observation; junior synonym].

Material. RUSSIA: KHABAROVSKIY KRAY, Okhotskii district: Bulginka River, near Bulgino village , 05. VIII.1998, 2 mature larvae, T. Tiunova; spring without name near Mount Three Brothers , ~ 3 km from the Okhotsk, 21 . VIII.1998, 1 m a l e imago (reared from larva), 3 mature larvae, T. Tiunova; Ul'ya River , 3 km upper mouth, 08 . VIII.1989, 1 male imago, V. Zherikhin; Ayano-Maiskiy district: Badzhalskiy Reserve, Lantar’ River Basin, Uluykan River , about 100 m above the mouth, 29 . VII.1999, 2 larvae, T. Tiunova; Sarafanovka River, 8 km from Ayan village , 02 . VIII.1999, 2 male imagines (reared from larva), T. Tiunova; Maya River, 2 km lower Nel’kan village, 5‒8 . VIII.1999, 1 male imago (reared from larva), 2 larvae, T. Tiunova; Elgandzhya River , upper reaches, 13 . VII.2003, 7 young larvae, T. Tiunova; AMURSKAYA OBLAST’: Tynda River Basin, Allenga River , bridge, at highway Zeya ‒ Snezhnogorsk, 5‒7 . VII.2013, 2 larvae, T. Tiunova; same locality, 06 . VII.2014, 1 larva, 1 larva (AM109), T. Tiunova; Allenga River , upper mouth, 29 . VI.2015, 1 larva, 1 larva (AM326), T. Tiunova; Tynda River, 500 m upper mouth of Allenga River , 30 . VI.2015, 1 larva (AM330), T. Tiunova; Zeyskii reserve, Bolshaya Erakingra River , 52-i km from Zeya, bridge, at highway Zeya ‒ Beregovoy, 06 . VII.2013, 2 larvae, T. Tiunova; MAGADANSKAYA OBLAST’, Ola River Basin: Donishko River , upper reaches of Ola River , 16 . VI.2014, 1 larva (AM137), E. Khamenkova; Ola River , upper reaches, 130‒137 km, 29 . IV.2014, 2 young larvae, 1 larva (AM152), E. Khamenkova; same locality, 30 . V.2014, 2 young larvae, 1 larva (AM389), 1 larva (AM141), E. Khamenkova; same locality, 16 . VI.2014, 3 young larvae, 1 larva (AM145), E. Khamenkova; KAMCHATSKI KRAII: Kamchatka Peninsula: Chimstina River , 07 . IX.2014, 1 young larva (AM207), I. Tiunov; Avacha River Basin, Ozernaya River , 28 . VII.2014, 1 mature larva (AM310), I. Tiunov; SAKHA YAKUTIYA, Timpton River Basin, Duray River , bridge, at highway Neryungri ‒ Yakutsk, 02 . VIII.2006, 1 larva, T. Tiunova.

FIGURES 59–61.

Description. Male imago (in alcohol). Length (mm): body 10.5‒11.4; forewings 8.6‒10.6; cerci 12.3. Head: Upper portion of the eyes brownish; lower portion blackish. Thorax: Medioscutum and submedioscutum light brown; median longitudinal suture narrow and brown. Anteronotal protuberance and sublateroscutum brown. Scutellum brown; scuto-scutellar impression pale. Posterior scuttle protuberance brown. Parascutellum dark (Fig. 59). Forelegs brown tinged dark; femur of middle and hind legs from yellowish to brownish, joints and tarsal segments slightly darker. Length (mm) of foreleg segments: femora 1.7‒1.9; tibia 1.6‒1.8; tarsal segments 0.4‒0.5, 1.1‒1.3, 1.0‒1.2, 0.8‒1.0, and 0.5. Wings hyaline: all veins brown. Abdomen: Terga I‒II and VII dirty brown; terga III‒VI brownish or dirty brownish, lateral margins darker. Sterna brownish. Styliger white and well contrasted medially with dark brown lateral margins. First segment of the forceps dark brown, sometimes lighter in the distal part; second and third segments light brown or brownish. Penis lobes brown proximally and light brown distally (Figs 60, 61); penis lobes rounded laterally and bent medially (Fig. 60); each ventral plate bears a large pointed apically denticle and several smaller subapical denticles (Figs 61‒63); the first small denticle is located at the base of main denticle (Figs 61, 63). Cerci brown with dark brown joints and pale tips.

FIGURES 62–63.

Mature larva. Length (mm): body 7.8‒11.3; cerci 3.3‒5.5. Head: Brown with a pale triangular spot from the median ocellus to the anterior margin of the clypeus and a pale median stripe between the eyes (Fig. 64). Antennae brownish with pale tips. Labrum (length 0.8‒0.83 that of the width) pale with a wide brown triangular spot not reaching the anterior margin (Figs 64, 66); this spot well expressed in young larvae, but may have a rectangular shape in mature larvae. Clypeus brown laterally (Fig. 66). First denticle incisor of the left mandible largest, the fourth smallest, the second equal to the third (Fig. 67); incisor of the right mandible with a wide third denticle longer than the first (Fig. 68). Labium whitish, shown in Fig. 69. Thorax: Pronotum and mesonotum brown with contrasting white stripes and spots (Fig. 65). Femur of the forelegs white with a large brown spot located near the anterior margin and extending to the ventral cleft; posterior margin brown (Fig. 70); femur of middle and hind legs with a brown spot medially; tibia of all legs brown in the anterior half and pale posteriorly; tarsus light brown in the middle and dark brown at edges; claws dark brown. Foreleg (mm): femur 1.2‒1.8; tibia 0.7‒1.0; and tarsus 0.9‒1.2.

Middle leg: femur 1.2‒1.8; tibia 0.7‒1.0; and tarsus 0.8‒1.1. Hind leg: femur 1.2‒1.8; tibia 0.7‒1.0; and tarsus 0.8- 1.1. Abdomen: Colouration of the larval abdomen variable. Larvae brown with contrasting pale maculation; all terga laterally white (Fig. 71); terga II‒VIII with a pair of diffuse dark oblique submedian stripes; tergum I often entirely light with an X-shaped dark spot in the middle or brown with a pair of small white spots; tergum II with wide, white transverse spot; terga III‒VI with a pair of bent white spots; tergum VII almost completely pale with a brown, V-shaped stripe only at the anterior margin; tergum VIII brown with a pair of white round spots near the posterior margin; posterior half of tergum IX white; tergum X white (Fig. 71). In some larvae, the white spot on the terga diffuse with a clearly visible pair of dark oblique submedian stripes. Terga with an almost regular row of spines (Fig. 73). Sterna pale; sternum I‒IX with pale lateral margins and a pair of white small spots near the anterolateral corners (Fig. 72); sternum I pale; sterna II‒V with a large blackish spot in the centre near the anterior FIGURES 64–65.

FIGURES 66–78.

FIGURES 79–80.

FIGURES 81–82.

margins; sterna VI‒VII with a pair of brown stripes near the lateral sides; sterna II‒IV with a diffuse brown semicircular submedian stripe; sterna V‒VII with a dark round spot near the anterior margin similar to the ganglionic markings; sterna VIII‒IX brown with pale spots, and sterna VII‒IX sometimes almost completely dark brown; abdominal sternum IX (female) with a deep incision (Fig. 74). Gills white; gill I small without an anal rib (Fig. 75) and just slightly smaller than gill II: width 0.50 of length; gills II-VII with an anal rib on the margins (Figs 76‒78); gill II: width 0.53 of length; gills III-VI with a rounded distal margin; width 0.54‒0.60 of length; gill VII slightly less than gill VI: width 0.53 of length (Fig. 78). Cerci brownish with a dark band in the middle (Fig. 65).

Distribution and biology. Russian Far East: Khabarovskiy Kray, Amurskaya and Magadanskaya Oblast’, Kamchatski Kray, Sakha Yakutiya. According to our data, adult emergence period from middle July to middle August.

Mature larvae and adults A. allengaensis sp. nov., A. sirotskii sp. nov., and A. camtschaticus were collected from small foothill Rivers (Figs 79‒82). Water temperature in the collection periods of larvae and reared imagoes did not exceed 10°С.

Remarks. Ameletus camtschaticus was described from a single male imago collected in Petropavlovsk (Kamchatka Peninsula) in 1927 ( Ulmer 1927). Sinitshenkova & Tshernova (1976) described the subimago male A. camtschaticus based on the similarity in the structure of the genitalia and the larvae by the similarity with adults in their size and distribution (all material was collected on the Kamchatka Peninsula). It should be noted that many of the details in the description of the larvae given in the above paper and in our description are completely consistent. The most important of which for larvae are that gill II has an anal rib, the lower edge of labrum light with a more intensely coloured medial spot with a triangle shape and a truncated apex, abdominal sternum IX with a deep incision, and the abdominal terga with contrasting pale maculation. However, the description of larvae by Kluge (2007) differs from both our description and that of Sinitshenkova & Tshernova (1976). Kluge (2007) indicated that gill II does not have an anal rib and abdominal terga are usually without contrasting pale maculation. In the present contribution, we used those specimens for which a molecular analysis was performed to describe the larvae of A. camtschaticus . All larvae in this group had an anal rib on gill II. Male A. camtschaticus imagoes were only considered in cases where they had been reared from larvae with an anal rib on gill II.