Because this beneficial is a fly, its larvae are called maggots. The non-stinging adult flies look much like bees with their yellow-and black markings. They feed on nectar and pollen, while the larvae are active insect predators. Larvae—small, pale, wormlike maggots—crawl among populations of pest insects and consume them as they go.
Larva: R.J. Reynolds Tobacco Company Slide Set, R.J. Reynolds Tobacco Company, Bugwood.org
Adult: Whitney Cranshaw, Colorado State University, Bugwood.org