Kirk: "All research personnel on alien planets are required to have their health certified by a starship surgeon at one year intervals.
Botany Bay wrote:
KIRK: Where's your wife? Where is she now?
CRATER: Dead. Buried up on the hill. It killed her.
CRATER: Oh, a year, or was it two?
Apparently the creature was able to fool one starship surgeon, and maybe two.
You know, if you think about it "Mantrap" would have been a perfect title for the episode Mudd's Women.