Libellulidae Rambur, 1842

Aksenova, Olga V., Potapov, Grigory S., Bespalaya, Yulia V., Kolosova, Yulia S., Vikhrev, Ilya V., Kondakov, Alexander V., Gofarov, Mikhail Yu. & Bolotov, Ivan N., 2020, Dragonflies from hot springs in Russia with a country-level checklist of species known to occur in geothermal environments, Ecologica Montenegrina 34, pp. 49-63 : 55-57

Family Libellulidae Rambur, 1842

Libellula quadrimaculata Linnaeus, 1758

Fig. 4A, 4B

Material examined. RUSSIA: Kamchatka Peninsula, Karymshina River valley, Karymshinsky hot springs, 52.8125°N, 158.0975°E, warm pool, 12 June 2013, 1♂ (newly emerged, near the pool) , 2 exuvia, Bolotov leg.

Field observations. These exuvia and adult specimen were collected on the shore of a small warm pool with water temperature of 30.5°С. This pool was situated in a mountain river valley that was largely covered by snow cover at the time of the sample collecting.

Distribution. Migratory species, which is widespread throughout boreal zone of the Holarctic Region ( Popova & Haritonov 2010). This species was previously recorded from hot springs in Canada ( Pritchard 1991; Corbet 2004) and around Lake Baikal ( Takhteev et al. 2006; Borisov 2014; Popova & Matafonov 2015).

Orthetrum melania (Selys, 1883)

Figs. 2C , 5E, 5F

Material examined. RUSSIA: Kunashir Island, Stolbovsky hot springs, 44.0072°N, 145.6831°E, around warm springs and streams, 29 July 2011, 18♂, 3♀, Bolotov, Kolosova & Potapov leg. ; Kunashir Island , Neskuchensky hot springs, 44.4856°N, 146.0981°E, around warm springs and streams, 24-26 July 2011, 20♂, 1♀, Bolotov, Kolosova & Potapov leg.

Field observations. We observed mating behavior of this species at the Stolbovsky and Neskuchensky hot springs. The egg-laying females occurred at the Stolbovsky area, where it was the most abundant Odonata species ( Table 2).

Distribution. Japan, Korea, continental China, Taiwan, and Vietnam ( Yong et al. 2014; Sasamoto et al. 2017), with a few geothermal populations on the Kunashir Island ( Sasamoto et al. 2017; this study). The Neskuchensky hot springs harbors the most northeastern population of this species. Several geothermal populations of this species are also known to exclusively occur in hot springs of eastern Hokkaido ( Corbet 2004; Sasamoto et al. 2017). Orthetrum -like larvae recorded in a geothermally heated section of the Kislaya River on the Kunashir Island [approx. 44.0036°N, 145.7672°E] ( Konakov 1956) most likely belonged to Orthetrum melania .

Comments. Morphological analyses of Orthetrum melania samples from the Kunashir Island indicated that these specimens belong to the nominate subspecies ( Sasamoto et al. 2017).

Sympetrum pedemontanum elatum (Selys, 1872)

Figs. 3C , 5G, 5H

Material examined. RUSSIA: Kunashir Island, Neskuchensky hot springs, 44.4856°N, 146.0981°E, around warm springs, 24-26 July 2011, 26♂, 18♀ (several of them freshly emerged), Bolotov, Kolosova & Potapov leg. ; the same locality, warm stream and pool (water temperature range 19.0 to 22.5°C), 26 July 2011, 4 larvae of various size (maximum body length 16 mm), Bespalaya & Aksenova leg.

Field observations. We observed mating behavior, mass emergence of the imago, and numerous exuvia near thermal streams on the Neskuchensky area, where it was the most abundant Odonata species during the observation period ( Table 2). Larvae were collected from a warm pool with water temperature 22.3°С and ground temperature up to 41°С, and from a warm stream with water temperature of 19.0°С, which flows into a hot stream at the foothill ( Fig. 3A ).

Distribution. This subspecies is endemic to Japan, Sakhalin, and Kuriles ( Popova 2004; Higashikawa et al. 2016). Asahina (1959) listed the occurrences of this species from Seseki [Goryachiy Plyazh geothermal site: approx. 44.0258°N, 145.8603°E] and noted that these specimens most likely migrated from Hokkaido.

Comments. Sympetrum pedemontanum elatum was considered a valid insular subspecies of the widespread Palearctic species ( Popova 2004).

Figures

Figure 2. Hot spring habitats and a live dragonfly on the Kunashir Island. (A) Neskuchensky hot springs, a habitat of Sympetrum pedemontanum elatum, Anotogaster sieboldii, and Orthetrum melania, 26 July 2011. (B) Stolbovsky hot springs, a habitat of Mnais costalis, Anotogaster sieboldii, and Orthetrum melania, 29 July 2011. (C) Male of Orthetrum melania near the Neskuchensky hot springs, 26 July 2011. (Photos: Yu. S. Kolosova [A, C] and O. V. Aksenova [B]).

Figure 3. Microhabitats in the Neskuchensky hot springs, Kunashir Island, and Odonata larvae collected from this geothermal source. (A) Scheme of microhabitats within the geothermal system with water and ground temperature measurements during the period of 24-26 July 2011 (before heavy monsoon rainfalls). The black symbols indicate collecting sites of Anotogaster sieboldii (circles) and Sympetrum pedemontanum elatum (squares) larvae. The color arrows indicate the oviposion sites of A. sieboldii before (green) and after (red) heavy monsoon rainfalls. (B) Larvae of Anotogaster sieboldii, 26 July 2011. Scale bar = 2 mm. (C) Larvae of Sympetrum pedemontanum elatum, 26 July 2011. Scale bar = 2 mm. (Photos: O. V. Aksenova).

Figure 4. Habitats, exuvium, and larva of Odonata in geothermal areas of the Kamchatka Peninsula. (A) Warm pool near the Karymshinsky hot springs, 12 June 2013. (B) Exuvium of Libellula quadrimaculata on the shore of this pool. (C) Lakelet Medvezhie in the Valley of Geysers, 13 August 2014. (D) Larva of Aeshna juncea collected from this lakelet. Scale bar = 2 mm. (Photos: O. V. Aksenova).

Figure 5. Odonata specimens from geothermal habitats of the Kunashir Island [RMBH]. (A) Mnais costalis, male, 29.vii.2011. (B) M. costalis, male, 29.vii.2011. (C) Anotogaster sieboldii, male, 26.vii.2011. (D) A. sieboldii, female, 24.vii.2011. (E) Orthetrum melania, male, 29.vii.2011. (F) O. melania, female, 29.vii.2011. (G) Sympetrum pedemontanum elatum, male, 26.vii.2011. (H) S. pedemontanum elatum, female, 24.vii.2011. Corresponding labels are presented below each specimen. (Photos: Yu. S. Kolosova).