Florida Keys

Screwworm-infected Key deer to be incinerated; sterile flies on way to combat outbreak

More than four dozen deer have been put down.
More than four dozen deer have been put down. Contributed

The number keeps growing.

More than 50 of the nearly 1,000 endangered Key deer at the National Key Deer Refuge on Big Pine Key have been euthanized in the past several months because of New World screwworm larvae infestation.

Refuge Manager Dan Clark said the U.S. Department of Agriculture and state officials are working to eradicate the screwworm and find out where the infestation came from. After hatching, screwworm larvae feed on the wounds of injured animals.

READ MORE: Infected deer in “gory conddition” (WARNING: GRAPHIC PICTURE)

The presence of the parasitic larvae for the first time in 50 years in Key deer, which grow to only about three feet tall, prompted the USDA to declare an agricultural emergency in Monroe County last week.

“I think one of the biggest things that tugs at the emotions is these aren’t dead animals. Some of these deer are walking down the street with these infestations,” Clark said. “We are talking hundreds and thousands of larvae.”

Those deer have been quickly put down with a shot to the head by bolt guns, modified pistols with a spring-loaded steel rod, Clark said.

Now, the deer are being frozen after death because not all larvae can be retrieved from the wounds of the deer due to how far they burrow down. Clark and staff at the refuge take parts of the carcass that are infected and freeze them in large coolers on refuge property.

Since space is running out, the USDA is sending in a large generator-powered freezer that was set to arrive over the weekend. Clark said an incinerator has also been purchased and is en route from Mississippi.

“We’ve been trying our best to have everything frozen in order to prepare to incinerate them,” he said.

Clark said that carcasses were being deposited in a safe spot away from the public where “nature can take its course.” That is still true for uninfected deer parts. But now, protocol has changed because leaving the screwworms in the bodies could result in the worms burrowing down into the ground where they pupate and mature, continuing the life cycle.

Since chemicals and pesticides have proven not to be effective in the past when eradicating the screwworm fly, Clark said the USDA could begin releasing sterile male flies to mate with female flies as soon as Tuesday.

This method has been used worldwide in the past for eradication. Female screwworm flies mate only once in their lifetime, storing male sperm to fertilize eggs in the future, so if it mates with a sterile male the life cycle is broken.

The eradication process will take three to four months, Clark said, and the flies would come from a USDA breeding location in Panama.

“We’ll be working actively into winter,” he said.

A voluntary inspection checkpoint at mile marker 106 in Key Largo also reopened Friday morning after being closed during Hurricane Matthew. Federal and state officials had inspected 100 dogs and four cats for signs of the screwworm since last Monday, said Jenn Meale, communications director for the state Department of Agriculture and Consumer Services. None of them showed signs of screwworm.

Meale also confirmed that two domesticated dogs and one pot-belly pig had been euthanized in Monroe County following the screwworm outbreak.

Katie Atkins: 305-440-3219