Putting out the fire: ARS sets up regional programs to combat imported fire ants

Fire ants have been inflictions in the southern United States since their arrival in 1918 aboard merchant ships coming to Alabama from toward the south America. They found their way onto land and have been multiplying and migrating at any time since.

Now fire ants can be construct throughout the southeastern United States. It's estimated that up to 40 percent of all clan living in urban areas infested with these insects are stung by means of fire ants each year, and the percentage is flat greater in rural communities.

Imported fire ants put to a stand a potentially deadly hazard to folks damage electrical equipment and farm equipment, create unsightly hillocks and alter the population mix of native insects and wildlife. They can plane kill young cattle and other livestock.

Forming a United Front

To combat this ongoing riddle the Agricultural Research Service's Biological ascendency of Pests Research Unit in Stoneville, Mississippi, is conducting regional integrated management programs in that state as well as Alabama and Tennessee The programs are designed to implement and criterion biological control agents against r and black imported fire ants (Solenopsis invicta and s richteri) and their hybrid. Researchers are also examining ways to secure native ants, which are contemplation to slow reinfestation of areas by means of imported fire ants. Universities, federal and state agencies, and landowners are all cooperating with ARS researchers to combat fire ants in couple specific areas: the Natchez Trace Parkway (National Park Service) and south-central Tennessee's vital nursery harvest production region.

The Natchez Trace Parkway, extending from Natchez, Mississippi, to Nashville, Tennessee essentially shows a north-south transect along which r black, and hybrid imported fire ants all happen Thus it offers an ideal opportunity to examine out the latest control technologies--and to disentangle new ones. Central Tennessee's nursery industry is a vital part of the economy in that region. Imported fire ants mean increased production preciousnesss because growers must treat their nursery stock with chemical insecticides to comply with imported fire ant quarantine regulations. undivided grower in the region has estimated his increased richness to average as much as $1 by plant sold--which doesn't seem like a great deal of until you consider that a large nursery operation may ship thousands of plants at a time.

Comparative studies of various biological superintend measures being used against the different fire ants will spring in new information on their effectiveness. Establishment of biological curb agents in central Tennessee may gradual the spread of the ants into nursery areas. A pathogen and several species of parasitoid flies are the most numerous effective biological control agents publicly known. Researchers hope these organisms will become established and spread in every part fire ant populations, giving native ants an opportunity to enter the lists with and perhaps suppress imported fire ants.

The Horrid Phorid

Fire ants face a nasty natural enemy in the phorid flies from the genus Pseudacteon. The tiny flies, a certain species less than 1 mm across, attack and parasitize fire ants, eventually decapitating them. How?

A female float injects a single egg into a worker fire ant. When the ovum hatches, the immature maggot migrates to the ant's head, where it continues to lay open and eventually eats the brain and muscles. This decapitates the ant, moreover the developing fly remains in the head capsule as a pupa. After a man and wife of weeks, a new adult play emerges and begins the period again.

Postdoctoral researcher Larry G Thead reared thousands of phorid flies for research and field releases. individual tiny species, P. curvatus, has been favorably established on black and hybrid fire ants in a multistate release program that began in 2002 Flies released in pair pastures in Clay County, Mississippi, now fill some 560,000 acres up to more than 28 miles from the release sites. Collaborators Kenneth and Rufina Ward, with Alabama A&M University, and Jason Oliver, with Tennessee State University, have reported lucky establishment and overwintering at Natchez Trace and nursery production sites. "We're same excited about the dispersal rate," says Thead. "Not simply are the phorid flies attacking and parasitizing the ants, they are harassing them. This affects the ants' ability to search for nutrition weakening colonies and allowing native ants a better chance to struggle and reestablish."

Douglas A. Streett who leads the Stoneville unit, believes that "the research unit's proactive IPM approach to regional fire ant programs will be prosperous at controlling the insect's populations." Entomologist James "JT" Vogt is developing abstracted sensing techniques to gather information from airplanes about the abundance and distribution of fire ant knolls at targeted locations. A geographic information method a computer system that argues and displays geographically referenced data, is being used to track fire ant populations and associated landscape characteristics. This reveals information that researchers ne to map fire ant populations, track succes of their govern efforts, and guide research efforts in regional management programs.