On Jan 30, 2012, alblueheron from Tampa, FL wrote:
Some juvenile acarid mites feed on dragonflies for a short time before leaving them to feed on their final hosts. These mites cover the thorax of this banded pennant, looking like red beads.
Dragonflies are important predators of mosquitoes and other biting insects found in their habitats. As such, they provide a great service to we humans who live there too.