# Presentation: 707112

## Slide 1

## The PROBLEM	

- Fire ants
- Were accidentally introduced into U.S. from South America
- Now infest more than 321 million acres in 13 states and Puerto Rico
- None of biological control organisms that control fire ants in South America were brought with them to the U.S.

- Fire ants

- Biocontrols
- left behind

- Fire ants

## Spread of Imported Fire AntsBlack imported fire ant introduced in 1918

## Spread of Imported Fire Ants

## Spread of Imported Fire Ants

## Spread of Imported Fire Ants

## Spread of Imported Fire Ants

## Spread of Imported Fire Ants

**1998**

- 318 million acres infested

## Problems Caused by Fire Ants

- Agricultural
- Higher production costs
- Increased risk of pesticides used to control fire ants
- Medical/Veterinary
- Sting people and pets
- Attack livestock and wildlife
- Equipment
- Short out electrical equipment
- Damage mowers and agricultural equipment
- Ecological
- Kill and eat ground-nesting birds and mammals
- Destroy predators and parasites of pests

## Components of Fire Ant Venom

- 95% alkaloids (6-n-alkyl, or alkenyl, 2 methyl piperidines)
- Potent necrotoxic effects (kill tissue and results in pustule formation)
- Do not produce allergic effects in humans
- 5% aqueous solution of proteins, peptides and small molecules
- One protein (Sol i I) causes allergic responses in people allergic to bee and wasp venom
- 3 other proteins are not related to bee or wasp venom

## Fire Ant Stings

- Sting is immediately painful
- Alkaloid venom kills tissue
- White pustule forms in ~24 h
- Heals in 10-14 days
- Trace amounts of protein in venom are similar to bee and wasp venom
- Highly allergic individuals may die

## The Goals:Areawide Suppression of Fire Ants

- Demonstrate practical, long-term control of fire ants over a large area using:
- Baits
- Biological controls

- 321 million acres infested

## The PROGRAM

- Cooperating states
- Locations in each state
- Two 300 acre sites
- Improved pasture
- Heavy fire ant infestations

## The PROGRAM

## Fire Ant Bait Treatments

- Baits
- Very effective
- Expensive
- USDA-ARS has worked to make oil-based baits commercially available to the public
- Hydramethylnon bait
- Fast acting: kills ants in 3-5 weeks
- Methoprene bait
- Sterilizes reproductives
- Prevents larvae from developing normally
- Effects are slow, but control lasts for months

## Biological Controls for Fire Ants

- Kill fire ants in their native South America
- Only recently brought to U.S.
- USDA-ARS has imported, isolated, and mass-produced these biological control organisms for release

## A Decapitating FlyPseudacteon tricuspis

- Attacks fire ant workers and causes them to hide instead of feed
- Life cycle
- Lay eggs on worker ants
- Larvae migrate to head and develop into adults
- Fire ant head falls off
- Adult flies emerge from severed head and attack other fire ants

## A Fire Ant DiseaseThelohania solenopsae

- Introduced into colonies by putting infected larvae in the mound
- The disease is caused by a protozoan that weakens the colony
- Weakened colonies mean fewer fire ant reproductives to start new colonies

## Fire Ant Disease (Thelohania) Effect on Fire Ant Colonies

- 0 months

- 12 months

- 5 months

- 8 months

## The PROGRAM

- Fire ant populations are reduced by aerially applying baits to each 300 acre pasture
- Natural enemies are released around the treated area
- Weaken and kill fire ants allowing native ants to repopulate
- Achieves sustainable control, reducing the need for repeated applications of expensive fire ant baits

## Expected RESULTS

- Release and spread of fire ant natural enemies
- Sustained fire ant control
- Lower livestock production costs
- Increased farmworker safety
- Reduced pesticide risk
- Restored ecological balance among native ants, birds, and wildlife

## ContactsPrincipal Investigators

- ContactsPrincipal Investigators

**Lead Agency: USDA-ARS**
**Roberto M. Pereira, Ph.D.**

**University of Florida**
**Phil Koehler, Ph.D.**

**USDA-ARS**
**Doug Street, Ph.D**.

**Oklahoma State University**
**Russell Wright, Ph.D.**

**Clemson University**
**Mac Horton, Ph.D.**

**Texas A & M University**
**Bastiaan Drees, Ph.D.**
**Charles Barr, Ph.D.**

**USDA-APHIS**
**Anne- Marie Callcott, M.S.**