This review may contain spoilers. I can handle the truth.
I've seen 'The Wicker Man' about half a dozen times, and it's only now occurred to me that Daisy's description of the beetle tied to a nail is plainly foreshadowing Howie's fate:
"The little old beetle goes 'round and 'round. Always the same way, y'see, until it ends up right up tight to the nail. Poor old thing!"