Bumblebees of the Subarctic Region in European Russia—Their Significance and Conservation ^†

Abstract

Regarding the bumblebee fauna, a number of regions of Russia are still insufficiently studied. These include Arkhangelsk Region, a large territory that is partly located in the subarctic region of Northern European Russia. In this research, we present information on the distribution of bumblebees of the studied region and discuss the bumblebee communities and also their conservation in Northern European Russia. The regional fauna of bumblebees is represented by species that are widely distributed in the Palaearctic. The species richness of bumblebees is highest in the valleys of large rivers and in secondary meadows due to the appearance of species that are not common of the zonal taiga ecosystems. These include Bombus ruderarius, B. veteranus, B. soroeensis, B. sichelii and other species belonging to a group of meadow species. One species, B. consobrinus, is considered as a rare species in the regional fauna. It is represented quite locally in most districts of Arkhangelsk Region. In the north of Arkhangelsk Region, B. consobrinus is most abundant in the native taiga habitats, but is rare in the other areas of the studied region. B. consobrinus in Arkhangelsk Region prefers the meadows near coniferous forests, where its main food plant, Aconitum septentrionale, is concentrated.

1. Introduction

Bumblebees (Hymenoptera: Apidae: Bombus Latr.) are one of the most thoroughly studied groups of Hymenoptera. There are approximately 250 species in the world fauna, confined mainly to temperate regions, i.e., Eurasia and North America [1].

Bumblebees are quite well adapted to the climatic conditions of the subarctic, in comparison with other groups of bees [2]. Their high adaptive capabilities in the development of high latitudes are primarily due to the features relating to their morphological structure, thermoregulation and life cycle [3]. Bumblebees are well-known as pollinators of many plant species.

At the same time, some territories of the Eastern European sector of the subarctic still remain insufficiently studied, due to their inaccessibility. In this research, we consider the distribution of bumblebees in the subarctic region of European Russia. We also discuss the bumblebee communities and their conservation in Northern European Russia.

2. Materials and Methods

Specimens of bumblebees (total N = 6725) in the studied region (the north of Arkhangelsk Region, according to the administrative division of Russia) were collected during the period 1994–2021 by researchers from the N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences (FCIARctic) and the Northern (Arctic) Federal University, named after M.V. Lomonosov (NArFU): PhD G.S. Potapov, PhD Yu. S. Kolosova, PhD M.V. Podbolotskaya, Dr. Sc. I.N. Bolotov, and V.M. Spitsyn. A number of specimens were studied in the collections of the Zoological Institute of the Russian Academy of Sciences (Saint Petersburg, Russian) and Finnish Museum of Natural History (Helsinki, Finland). Our collected specimens of bumblebees were deposited in the Russian Museum of the Biodiversity Hotspots (RMBH) of the FCIARctic, Arkhangelsk, Russia. The species of bumblebees were identified according to Løken [4,5], Panfilov [6], Rasmont and Terzo [7]. We used DNA barcoding for the reliable identification of the Bombus lucorum complex [8].

3. Results

A total of 28 species of bumblebees are found in the north of Arkhangelsk Region [9]. The presence of B. modestus Eversmann, 1852 in the studied area requires additional research [9]. The most common species in the majority of communities of bumblebees are B. cryptarum (Fabricius, 1775), B. pascuorum (Scopoli, 1763), B. hypnorum (Linnaeus, 1758), B. veteranus (Fabricius, 1793), and B. hortorum (Linnaeus, 1761). Typical foraging habitats for these species of bumblebees are meadows in the vicinity of settlements (Figure 1). Bumblebee species, such as B. schrencki Morawitz, 1881, B. consobrinus Dahlbom, 1832, B. pratorum (Linnaeus, 1761), and B. jonellus (Kirby, 1802), mainly prefer ruderal communities near native taiga as foraging habitats.

4. Discussion

The species richness of bumblebees is highest in the valleys of large rivers and in secondary meadows due to the appearance of species that are not common in the zonal taiga ecosystems. It was previously noted [10] that in the conditions of anthropogenic landscapes in European North, the bumblebee communities are enriched with species of a more southern origin, i.e., a group of meadow species. They are not widespread in the native taiga ecosystems and are common for more southern biomes than the taiga [10]. These include B. ruderarius (Müller, 1776), B. veteranus, B. soroeensis (Fabricius, 1777), B. sichelii Radoszkowski, 1860, and other meadow species. The species of bumblebees, such as B. schrencki, B. consobrinus, B. cingulatus Wahlberg, 1854, B. pratorum, and B. sporadicus Nylander, 1848 belong to a group of forest species and are typical of native taiga habitats [11].

A total of 27 species of bumblebees recorded within the lower reaches of the Northern Dvina represent approximately 80% of the fauna of the taiga zone of Northern European Russia [9]. This is quite a large number compared to other regions. For example, in the agroecosystems of Finland, there are 15 species of bumblebees [12]. Differences in species richness are primarily associated with the degree of transformation of ecosystems during agricultural impact and partly with the zonal gradient. Therefore, in agroecosystems there is a rapid degradation of bumblebee communities due to intensive farming. On the contrary, in Northern European Russia there was a sharp decline in agricultural production and the development of succession processes on agricultural land in the 1990s [10]. This factor has undoubtedly had a positive impact on bumblebee communities in our region.

One species of bumblebee in the studied region is rare. B. consobrinus is presented quite locally in most districts of Arkhangelsk Region. This species is considered as oligolectic in Fennoscandia and is related to Aconitum septentrionale [4,13]. The range of A. septentrionale includes the studied region. This species of plant has been recorded in native taiga ecosystems of the Belomorsky–Kuloysky plateau and along the major rivers of the north of Arkhangelsk Region [14]. A. septentrionale does not have a conservation status in this region, because it is quite common.

Hence, in the north of Arkhangelsk Region, B. consobrinus is most abundant in the native taiga habitats, but is rare in the other areas of the studied region [9,11]. B. consobrinus in Arkhangelsk Region prefers the meadows near coniferous forests, where its main food plant, i.e., A. septentrionale, is concentrated [14]. B. consobrinus is also rare in Finland and Karelia [13]. Due to this reason, B. consobrinus is vulnerable to anthropogenic changes in habitats. It is included in the Red List of Species of Arkhangelsk Region [15].

5. Conclusions

Further studies of bumblebees in the subarctic region of Northern European Russia should be aimed at the monitoring of bumblebee communities in anthropogenic landscapes. The decline in bumblebee populations under anthropogenic influences may have consequences such as the disappearance of some species from the regional fauna.