Research Article |
Corresponding author: Mikhail V. Kozlov ( mikoz@utu.fi ) Academic editor: David C. Lees
© 2021 Maria V. Gavrilo, Igor I. Chupin, Mikhail V. Kozlov.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Gavrilo MV, Chupin II, Kozlov MV (2021) Carried with the wind: mass occurrence of Zeiraphera griseana (Hübner, 1799) (Lepidoptera, Tortricidae) on Vize Island (Russian High Arctic). Nota Lepidopterologica 44: 91-97. https://doi.org/10.3897/nl.44.63662
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Vize Island, located in the northern part of the Kara Sea (79°30’N, 76°59’E), is one of the least studied islands of the Russian High Arctic in terms of its biota. Hundreds of live and freshly dead individuals of Larch Budmoth Zeiraphera griseana (Hübner, 1799) were observed on this island from 16 July–2 August 2020. This is the first and the only terrestrial invertebrate ever discovered on Vize Island. The moths were likely transported to the island by air currents from the northern part of the Krasnoyarsk region, where an outbreak of Z. griseana was reported on over 75,000 ha. The distance travelled by moths approached 1200 km. Thus, the high Arctic islands are less isolated from insect migrants than was commonly thought. These islands will be colonised by boreal insects as soon as changing environmental conditions allow the establishment of local populations.
Arctic habitats have fascinated biologists for centuries. Nevertheless, their species-poor insect faunas provide little reward for entomologists to justify spending several weeks or even months in the hostile environments of tundra or polar deserts. Consequently, the data on insects from the high Arctic islands, excepting the Svalbard Archipelago, are based only on occasional collecting and therefore remain scarce. This is particularly true for moths and butterflies: ten Lepidoptera species (three residents and seven migrants) were discovered in Svalbard (
This scarcity of data prompts entomologists to appreciate any observation on insects made in the high Arctic and to carefully collect information on occasional migrants (e.g.
Vize Island (discovered in 1932) is located in the northern part of the Kara Sea (79°30’N, 76°59’E), 575 km from the mainland and 275 km from the Severnaya Zemlya Archipelago (Fig.
The expedition by the Arctic and Antarctic Research Institute (Russia) visited Vize Island from 9.vii.–30.viii.2020. Its aim was the exploration of Ivory Gull, Pagophila eburnea (Phipps, 1774) ecology, but the researchers used their stay on the island to perform the first systematic study of its biodiversity. Insects were searched by sweeping entomological nets over plants and by visual examination of flowers and moss carpets; they were also recorded during general faunistic surveys. The collected moths were preserved in paper envelopes; their identification was confirmed by examination of the male genitalia. Several specimens were relaxed, pinned and donated to the Zoological Institute (St. Petersburg) and to the Finnish Museum of Natural History (Helsinki). Weather data were downloaded from an open access web source (rp5.ru).
The persistent transition of daily air temperature through zero occurred on 30.vi.2020. The summer of 2020 was exceptionally warm, with mean air temperatures of 1.98 °C and 4.45 °C in July and August, respectively (Fig.
The live and freshly dead Z. griseana moths were first observed on 16.vii.2020 on the sandy banks of a pond near the meteorological station. On 19.vii, multiple freshly dead moths were discovered on sandy banks of rivers and streams along the 6 km route across the tundra north-east from the station. A total of 215 dead moths were counted within a 5 × 112 m area at the sandy bottom of a river valley with shallow (10–15 cm depth) streams, resulting in one moth per 2.6 m2. Moths, single or in groups, were mostly found at the water’s edge, along with some fine floating debris (Fig.
Examples of habitats on Vize Island and moths Zeiraphera griseana (Hübner, 1799). 2. The typical landscape: forb and cryptogam high-Arctic tundra. 3. Shallow river valley, at the sandy banks of which dead moths were observed. 4. Dead moths at the stream bank. 5. Live moth sitting on the ground.
Weather conditions on Vize Island in summer of 2020. Red line: mean daily air temperature (°C); bars: mean daily wind speed blowing from south-east quarter (m/s; days with winds 9–10 m/s are shown by dark green bars); blue line: days with negative minimum air temperature; purple circles: days when live Zeiraphera griseana (Hübner, 1799) moths were observed.
The Larch Budmoth is widely distributed across Palearctic, reaching or approaching the northern distribution limit of coniferous forests in Finland (http://www.laji.fi), the Kola Peninsula in northwestern Russia (
Migratory behaviour is typical for Z. griseana, but the active migrations generally occur at the regional scale and are associated with severe defoliation of their host plant (
By contrast, outbreaks of Z. griseana in Siberia, resulting in severe damage of larch forests, have been documented since 1966 (
Thus, our observation of the mass occurrence of Z. griseana moths on Vize Island confirms that the poleward migration of this species is a sporadic but relatively frequent event. We suggest that moths were transported to this island on 12–14.vii.2020 by strong winds directed from the continent. The nearest potential source population was located in the northern part of the Krasnoyarsk region (Fig.
The dispersing insects generally require warm and dry conditions for take-off (
We conclude that the high Arctic islands are less isolated from insect migrants than is commonly thought. The successful arrival of a large number of live moths from continental Siberian forests to Vize Island has once more demonstrated the absence of insurmountable physiological barriers to initial colonisation of high-Arctic islands by boreal insects.
The expedition work was carried out within the framework of the Scientific Research Plan of the Arctic and Antarctic Research Institute for 2020. We are grateful to the staff of the Polar Station Vize for their hospitality, and we thank our colleague Yu. Davydova and Vize station technician V. Khrustalyev for their valuable assistance and three reviewers and David Lees for their comments. The publication was supported by the Societas Europaea Lepidopterologica (SEL).