It’s hard to believe, but some people thought that a butterfly is an evil, demonic soul, and a messenger of death (for example, if it flew into the room of an ill person, that was a sign of the imminent death). The South Slavs believed that when the veshtitsa (witch) falls asleep, her soul in the form of a butterfly strangles, sucks blood, steals milk or fire, etc. And if her body is turned face down, her soul will not recognize it, and will remain a butterfly of a striking color like black and red or black and yellow. When the body of a vampire is burned or pierced with a stick, as the Serbs believed, his soul also flies out in the form of a butterfly or many butterflies. To neutralize him, the butterfly had to be killed.
Western Slavs also associated these cute insects with death, disease, and demons. This is reflected in the name of the butterfly in different West Slavic dialects: diabel, čertica, mara, vampir, bieda, etc. The most frequent association with evil and death is represented by the butterfly called “Dead Head” (Acherontia atropos), which even was featured in the movie “The Silence of the Lambs”.
After that, will you be able to look at the butterflies with the same eyes, especially the black and yellow ones?
More interesting facts can be found in: “Slavic Antiquities” – encyclopedic dictionary in 5 volumes by Institute for Slavic Studies of the Russian Academy of Sciences.