Murray, you are right that a Hornie-Goloch is an earwig aka a "Forkietail" but in the context of the song the emphasis is on the "hornie" part. And a Tattie-bogle is a scary thing put in a tattie or potato field to shoo the birds away. The words, according to Connolly, are by his pal, Leo McGuire and are mainly Glasgow dialect. Why are we doing scholarly analysis on a humorous parody, anyway? (And don't tell me that's a dangling preposition). On that subject, a young lady, on hearing my accent, asked me where I was from. Scotland, I said. Oh, says she, have you ever seen the Loch Ness Monster? Everytime I unzip my pants, says I. (End of conversation and possible friendship).