Where does “selkäpiitöin” come from?

selkäpiitöin (Ingrian) comes from Finnish selkäpii, from Finnish pii, from Swedish bi, from Old Swedish bī, from Old Norse bý, from Proto-Germanic biją, from Proto-Germanic bijǭ, from Proto-Indo-European bʰey- — bee.

selkäpiitöin (Ingrian): invertebrate