This article is devoted to an analysis of possible bivoltine development of several bumblebee species in
Europe. This study is based on materials collected by the authors in European countries (Slovakia, France
and Greece) and in the European North of Russia (Solovetsky Archipelago). Four bumblebee species
were studied. They are Bombus hortorum, B. terrestris, B. pratorum and B. jonellus. Bombus hortorum was
collected from south-eastern Slovakia and southern France, B. terrestris was additionally from the Isle of
Crete, B. pratorum was from southern France and the Solovetsky Archipelago, and B. jonellus was collected
only on the Solovetsky Archipelago. Our records reveal that several bumblebee species may have two
generations per season. Bombus hortorum and B. pratorum in south-eastern Slovakia and southern France
had males present in late May. Both these species have a short life cycle, so they are potentially able to
produce two generations in a season. Bombus terrestis was found in January on southern France and in
Late November in the Isle of Crete. Because this species has no obligate diapause, this fact may indicate
bivoltine development for B. terrestris in the studied territories. The potential ability of B. jonellus to produce
two generations per season was revealed during long-term research on the Solovetsky Archipelago.