Which global industry is worth almost £6bn? That’s correct, it’s worms. For fishing. And which country appears to have let the market wriggle through its fingers? Right again. We have.

With spring blooming along streams and lakes in eastern Alabama, Corbin Hart is out testing the waters with his fly rod. The Winter Haven native is president of the Auburn University Fly Fishing Club.

He asked fishing lure companies which colors and scents sell. Their unanimous response? Day-Glo green and garlic flavor. After four years of food dye experiments, he created “Nitro Worms” in ...