Flies you Might Like

December 20, 2016


Phorid fly attacking red imported fire ant photo by Jeffery Lotz


Ouch- the red imported fire ant, we all know this tic-tac sized fierce biting nuisance. You probably stepped in a pile of these ants as a child or know someone who has, so you know how painful they can be. Unfortunately, this fire ant problem is not just in Florida. They have been found across the southeastern United States and even in Puerto Rico.  While these are troublesome pests to people, they are even more problematic for agriculture, natural environments, and wildlife including native ant species, deer, turtles, alligators, rodents, birds, and other ground nesting animals.

Help is on the way via a natural solution…

The red imported fire ant comes from South America where a group of tiny phorid flies are its natural enemies. These host-specific flies attack and parasitize the fire ant, resulting in its death.

The fly injects its egg into the midsection of the ant, the egg hatches and the larva (maggot) lives for two to three weeks within the ant, eventually traveling to the ant’s head where it releases an enzyme which causes the head to fall off. The phorid fly maggot ingests the contents of the head capsule and then utilizes it as a pupal case.


Pictured from left: Amy Croft, Shanna Swiers, Catherine White, Elise Schuchman, and George Schneider

Phorid flies have been reared at the Division of Plant Industry in partnership with the USDA since 2001 with the help of dedicated and skilled team members who attend to these flies daily. Since its start, there have been four species of phorid flies reared at DPI’s Gainesville location, each attacking different sized worker ants and active at different times.

Fire ants are collected in the field and brought back to the DPI Gainesville lab. Once in the lab, technicians place them in attack boxes which are specially designed to prompt movement of the ants allowing phorid flies to attack. Once the flies have been introduced to the attack boxes, the ants remain exposed for 48 hours allowing for maximum parasitization to take place.

Parasitized ants are distributed throughout the southeast to agricultural lands such as cattle farms and other natural areas which are then monitored for impact. While these flies are not available for distribution to the general public, the work being done helps to manage the imported fire ant numbers.


Pictured from left: Haley Lower, AJ Wilson, Liam Patrick, Daniel Ammann

Few other organizations research the phorid fly, which makes the work done at the Division of Plant Industry so important.

Between July and September alone, 349,614 phorid flies were reared at the Gainesville location, adding to the millions reared over the past 15 years.

It is the hope that releasing phorid flies will reduce the chemical control applications used on fire ants, thus reducing harmful impacts of these pesticides on humans, wildlife, and the environment.

Let the team know!

Share your thoughts in the comments and let us know what you think about the work DPI and the USDA are doing!







Dr. Gordon Bonn, Supervisor of the Marinas and Canals program, Division of Plant Industry, pauses at the entrance to the 2016 Miami Boat Show. He and other agency representatives greeted hundreds of attendees over the President’s Day weekend, reminding them to help exclude invasive pests from U.S. shores.

The Florida Department of Agriculture and Consumer Services had a strong presence at the Miami Boat Show over the President’s Day weekend, stressing the message, “Don’t Pack a Pest” and urging people to watch for and report the giant African land snail.

“We had many people visit our kiosk in the Central Courtyard to view our outreach materials and take home a message of Don’t Pack a Pest,” said Dr. Gordon Bonn, Supervisor  of the Marinas and Canals program, Division of Plant Industry.

The Don’t Pack a Pest program is administered by FDACS in partnership with the U.S. Department of Agriculture and U.S. Customs and Border Protection. The program’s goal is to make international travelers — including boaters — aware of the dangers of bringing agricultural products into the United States.


Jennifer Mestas and Detector Dog Jammer greeted visitors to the kiosk at the Miami Boat Show. In 2015 alone, interceptions of invasives included: white fly, sage plum moth, Lygus bug, European pepper moth, kaffir lime leaves, mealybug, Hawaiian glaber, California pea leafminer, and olive fruit fly and the giant African land snail.

The giant African land snail has been the subject of an eradication program in South Florida that began in August 2011. The snail is known to consumer more than 250 kinds of crops, poses a danger to human and animal health and can damage structures.

As a regulatory agency of the Florida Department of Agriculture and Consumer Services, the Division of Plant Industry works to detect, intercept and control plant and honey bee pests that threaten Florida’s native and commercially grown plants and agricultural resources.




Good news: As of February 25, FDACS and USDA reported that no additional Mediterranean fruit fly has been found since the discovery of two Medflies on February 10 in Pompano Beach.

To address the outbreak, FDACS has placed 1,473 traps in a 51-square-mile area around the positive find. The traps were checked daily, but because no additional fly was found, the traps will now be checked on a weekly basis.

A regulatory boundary (2011 Pompano Beach Medfly Regulated Area) has been established around the area of the positive find to prevent the spread of Medfly. Homeowners within the regulatory boundary should follow these guidelines until eradication is completed:
-Do not move any fruits and vegetables off of your property.
-Pick up any fallen fruits and vegetables from the yard.
-Double-bag fruits and vegetables in plastic. Securely tie bags and leave them out for household garbage pickup, not yard waste.
-Allow state or federal representatives access to your property for survey, trapping or treatment activities.

The next phase of the Medfly eradication program involves utilizing the Sterile Insect Technique, a biologically-based reproduction control method that releases large quantities of sterile male Medflies to outnumber the potential for mating by wild males. Wild female insects that mate with sterile males do not produce offspring, interrupting the reproduction cycle. FDACS began releasing sterile male Medflies in a 60-mile area near Pompano Beach on Sunday, February 27. Weather permitting, flies will be released three times a week throughout the duration of the eradication program. Currently, the eradication program is scheduled to end this May. If another Medfly is found, the eradication program will be extended for three Medfly life cycles.

 The Sterile Insect Technique is an effective method of eradication because it is safe for the environment and the public. Since 1999, FDACS and USDA have been operating a Sterile Medfly Preventative Response Program, which involves the release of Medflies in high risk areas of the state.

It is important to note that although wild Medflies can be devastating to agriculture and its more than 260 host plants, they are not harmful to humans. For more information about the Medfly response, visit http://www.freshfromflorida.com/pi/medfly or contact DPI’s helpline at 888-397-1517.

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