1. In a medium saucepan set over high heat, bring 1/2 cup water to a boil. Add the sugar and corn syrup; stir to dissolve. Return the mixture to a boil, cover, and cook 2 minutes.

2. Uncover; continue cooking until a candy thermometer registers 280 degrees, 15 to 18 minutes. Remove pan from heat. Line two baking pans with Silpat mats (French nonstick baking mats). Set pans aside.

3. Stir in lime oil, ginger oil, and echinacea. Transfer mixture to a 1-cup heatproof liquid measure. Pour approximately 1/2 teaspoon syrup onto a mat, forming a drop. Repeat, spacing drops 1 inch apart. If the mixture becomes too hard to pour, warm in microwave 10 to 15 seconds. Let cool completely. Wrap lozenges individually in cellophane or store on sheets of parchment in an airtight container up to 3 weeks.