Answer: Red dye for their uniforms.
The cochineal (the female in the photo does not have wings) feeds on cacti and was mostly found in South America, harvested and prepared by Spain. Still, there were some harvested in Carolina (yes, there are cacti in Carolina, especially when you cultivate it), although it was not as highly valued as the Spanish variety, requiring as much as three times as many female cochineals. To get the dye required scalding, drying, and pulverizing 70,000 insects to obtain a single pound of dye. The Spanish were quite adept at cultivating cochineal, having also learned to chemically treat the cochineal dye to create carmine.
A June 1716 entry in the journal of the Board of Trade and Plantations shows that British officials pondered the use of Carolina cochineal versus the Spanish variety:
The British were always looking for ways around the Spanish trade. It had become quite a habit since Elizabethan days. Certainly, the British needed a lot of red dye!