My only nitpick is the language used by the author in one specific sentence. I’m not sure if that was the author’s intent but the word “justify” in the sentence “This belief was used in the 1930s to justify keeping honey bees in thin-walled hives even in -30 °C climates.” gives the impression that the practice was intentional mistreatment, rather than a mistaken practice based on bad data that was just never corrected until now.

Other than that, this is a very good thesis.