The subfamily is named for Old World genus
Cetonia (e.g.,
Cetonia aurata). Origin of name is obscure--
The Century Dictionary (1) does not list an etymology, stating simply that it is New Latin (NL). Perhaps there is a connection with Greek
ketos (κετος), whale. (Leach also described many marine species, so this is plausible.)
Other possibilities: One Internet
source says that
ceton is
Gaulish for woods, forest.
Ceton (or
Seton) is a surname as well, so perhaps this is an eponym.