Authorities in the state are using drastic measures to stop the spread of the parasitic New World screwworm in the Florida Keys. Quarantine and sterilized males are being used to stop the first outbreak in over 30 years.

USDA and state officials use radiation to sterilize male screwworms, which are actually a species of fly. The male flies are then released to mate with the females. Any eggs that are laid won’t hatch thus killing the population.

The Florida Commissioner of Agriculture, Adam Putnam, declared a state of emergency after confirming an infestation in Key deer on Sept. 30. That particular subspecies of white-tailed deer is an endangered species making the containment of this issue all the more important.

"While it sounds like a Halloween joke, it poses a grave threat to the last population of the subspecies of Key Deer," Putnam told CNN. "And if it gets beyond the Keys, it represents an enormous threat to the US livestock industry, because of potential quarantines and trade barriers that could occur if it gets into the livestock population."

The screwworm can grow as large as common houseflies only with orange eyes. They lay eggs in open wounds in mammals and the hatched larvae feed on living flesh.

Infestations are easy to detect in humans and pets according to reports. An animal health checkpoint has been set up by USDA’s Animal and Plant Health Inspection Service for residents and visitors.