Catocala helena Eversmann, 1856

Knyazev, Svyatoslav A., Gorbunov, Pavel Yu., Melyakh, Sergey F., Nedoshivina, Svetlana V., Grebennikov, Nikolai D. & Matov, Alexey Yu., 2021, The first record of Catocala helena Eversmann, 1856 (Lepidoptera, Erebidae) in Europe with notes on its distribution in Russia, Ecologica Montenegrina 40, pp. 68-74 : 69-73

Catocala helena Eversmann, 1856

(figs. 2,3,4)

Material examined. RUSSIA: Samara Region, 1 specimen , Oktyabrsk town , 53°9'49.20"N, 48°40'14.61"E, at light, VII.2020, V. Yarutkina leg. (private collection of S. V. Nedoshivina, Ulyanovsk) ; Orenburg Region, 1♂ , Orenburg District, Pavlovka village , 51°52'1.43"N, 54°57'42.03"E, at light, 28.VII.2018, N.D. Grebennikov (private collection of N.D. Grebennikov, Orenburg, Russia) ; Orenburg Region, 1♂, 1♀ , Sol- Iletsk District, Berdyanka river valley, 51°24'57.97"N, 55°24'3.23"E, at light, 24-26.07.2019, M. Rantala leg. (private collection of M. Rantala, Helsinki, Finland) ; Orenburg Region, 1♂ 1♀ , Novoorsk District, 4 km NE of Zakumachnoye village, Big Kumak river , 51°16'19.19"N 59°11'18.13"E, at light, 23-24.VII.2019, S.F. Melyakh leg. (private collection of S.F. Melyakh, Ekaterinburg, Russia), 1♂ 1♀ , same locality, at wine traps, 27-28.VII.2020, S.A. Knyazev and P.Yu. Gorbunov leg. (private collection of S.A. Knyazev, Omsk, Russia) ; Orenburg Region, 2♂ , Gai District, 3 km N of Beloshapka village Guberlya Mts. , Guberlya river, 51°14'45.64"N, 58° 4'51.74"E, at wine traps, 28-29.VII.2020, S.A. Knyazev and P.Yu. Gorbunov leg. (private collection of S.A. Knyazev, Omsk, Russia); 1♂ , Orenburg Region, Belyaevka District , 3,5 km E of Novoorlovka village, Ural river, 51°23'14.09"N, 56°36'47.88"E, at wine traps, 29-30.VII.2020, S.A. Knyazev and P.Yu. Gorbunov leg. (private collection of S.A. Knyazev, Omsk, Russia) ; Novosibirsk Region, Novosibirsk City, Vatutina str., 54°59'27.24"N, 82°52'55.45"E, 2.VIII.2020, I.S. Sukhov (photo, https://www.inaturalist.org/observations/55131575) .

Bionomics. Optimal habitats for the species in Mongolian and Daurian parts of the species distribution area are dry summertime steppe creek valleys and gulleys with growing trees of Ulmus pumila ( Ulmaceae ) as well as sandy riverside slopes and terraces with groves of Ulmus pumila ( Benedek, Balint 2013) . Ulmus species were reported as the basic biotopical feature and as fodder plants ( Dubatolov et al. 2004; Dubatolov, Dolgih 2009) similarly to those of a systematically close species Catocala deuteronympha Staudinger, 1861 , that mostly occurs together with Catocala helena . The most numerous populations of Catocala helena were recorded in the valley of the Selenga and its large tributaries (А. Saldaitis, personal communication) in south-west Transbaikalia, where the species was originally described.

In new locations the species was found in the valleys of the rivers Volga, Ural and the tributaries of its basin– rivers Berdyanka, Guberlya, Big Kumak, further Ob` river where Ulmus laevis and U. pumila (supposedly being larval food plants there) grow. In the South Urals Catocala helena was attracted to the wine baits with the complex of the following species: Catocala deducta Eversmann, 1843 , Catocala nupta (Linnaeus, 1767) , Catocala orientalis Staudinger, 1877 , Catocala fraxini (Linnaeus, 1758) , Catocala lupina Herrich-Schäffer, 1851 , Amphipyra pyramidea (Linnaeus, 1758) , Amphipyra livida ([Denis & Schiffermüller], 1775), Agrotis ipsilon (Hufnagel, 1766) . The flight period in different parts of the species range is from the end of July to the middle of August оr September. In the South Urals the beginning of moths flight period is recorded in the last third of July.

Distribution. European part of Russia (Samara Region), South Urals (Republic of Bashkortostan, Orenburg Region), West Siberia (Novosibirsk Region), Irkutsk Region, Transbaikalia, Amur, Khabarovsk and Primorye territories in the Russian Far East, Mongolia, Korea, China ( Kononenko 2010; Knyazev 2011).

Discussion. We suppose that Catocala helena findings in West Siberia and in the Urals are due to fast natural expansion of the species habitat to the west at 50- 55° north latitude as a result of human activity and climate change. The prerequisite for that was formed by emerged secondary habitat of Ulmus pumila in West Siberia in the form of numerous local populations of probable food plant (species of the genus Ulmus ). It cannot be denied that in the South Urals there exists a local population of the species: findings in Orenburg Region have become pretty regular and numerous to make such conclusions possible. It may also be noted that on the basis of available data the presence of the species populations is possible in Saratov, Kurgan, Tyumen, Omsk Regions, Republics of Khakassia and Tyva of the Russian Federation as well as in the North Kazakhstan.

In recent decades, there has been a similar expansion of some species of diurnal butterflies, such as Maniola jurtina (Linnaeus, 1758) , Apatura iris (Linnaeus, 1758) and some others, to Siberia ( Knyazev, Kosterin 2003; Kosterin et al. 2007; Yakovlev et al. 2014).

Aknowledgements

The authors thank Markus Rantala (Helsinki, Finland) and I.S. Sukhov (Novosibirsk, Russia) for the permission to use their observations in the paper. We also thank Aidas Saldaitis (Vilnius, Lithuania) for Catocala helena range clarification. The research of S. V. Nedoshivina was supported by RFBR and Ulyanovsk Region , project number 19-44-730010. The work of Alexey Matov was performed in the frames of the state research project АААА- А19-119020690101-6 .