Pineapple weed has long been used as a successful insect repellent by indigenous peoples of North America. Scientists at the ARS Natural Products Utilization Research Unit in Oxford, MS, conducted a study to identify chemical constituents responsible for repelling mosquitoes. They found that essential oil from dried pineapple weed deterred mosquitoes from biting as effectively as DEET, which is used in retail mosquito repellent products.

The most active compounds isolated from pineapple weed (alpha-terpineol, spathulenol, and neryl isovalerate) provided complete protection. Neryl isovalerate was discovered here for the first time to have mosquito repellency. Most importantly, this research provides scientific evidence that validates the traditional use of pineapple weed as a biting-insect deterrent and reveals a potential natural alternative to widely used synthetic insect repellents.