This enormous bumblebee was slowly awaking in the sun on the first real spring day this year, a female from the Buff-tailed bumblebee group and I think a queen.
The bumblebee carried a number of mites that had dug in in her neck on both sides of her body.
The appearance of the Buff-tailed bumblebee group queens in the beginning early in the year indicates the start of the new season.

References
1 Gokcezade, J & Gereben-Krenn, B.-A & Neumayer, Johann & Krenn, Harald. (2010). Feldbestimmungsschlüssel für die Hummeln Österreichs, Deutschlands und der Schweiz (Hymenoptera, Apidae). Linzer Biologische Beiträge. 42.