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. F., et al. Feldbestimmungsschlüssel für die Hummeln Österreichs, Deutschlands und der Schweiz (Hymenoptera, Apidae).