The cryptic bumblebee species of Bombus lucorum-complex are one of the challenges for conservation management. They are morphologically indistinguishable in much of their range, which in most cases leads to misidentification. Among the regions of Northern Europe, reliable data on their distribution exist for Britain, Ireland, and Finland. In this paper, we studied the distribution of cryptic species of B. lucorum-complex, i.e. B. terrestris (Linnaeus, 1758), B. lucorum (Linnaeus, 1761), and B. cryptarum (Fabricius, 1775) in Northern European Russia. The species B. lucorum-complex are among the most widely distributed in Northern Europe. There are some data for the Kola Peninsula, whereby DNA barcoding confirmed the presence of only B. cryptarum among this complex. In general, there is actually no information on the distribution of the species of B. lucorum-complex in Northern European Russia.
We studied over 300 specimens. Morphological characters were used for initial species identification. After that, we used the PRC-RFLP method. For the verification of this method, the prepared samples were transferred for molecular analysis. B. cryptarum was found in the northern and southern part of the Murmansk Region. B. lucorum was recorded only in the south of this region. In Karelia, the higher the proportion of B. lucorum in the samples is in the southern part of the region. Among the species of Bombus lucorum-complex, three species were found in the Arkhangelsk Region, i.e., B. cryptarum, B. lucorum, and B. terrestris. Only B. cryptarum is recorded in the extreme northern localities of this region. B. terrestris is found only in the south–east of the Arkhangelsk Region. This pattern is generally consistent with what is known for Finland, i.e., B. cryptarum are dominant among the species of B. lucorum-complex in bumblebee communities in Northern Fennoscandia.