ScienceDaily (Aug. 21, 2009) — Two separate strategies for reducing the spread of red imported fire ants (RIFA) are being combined by Agricultural Research Service (ARS) scientists as part of a strategy that could potentially add to the arsenal against this spreading pest.

Currently, parasitic phorid flies are used in the United States to help control some fire ant populations. In Argentina, pathogens like Kneallhazia solenopsae and Vairimorpha invictae—alone or in combination—are associated with localized declines of 53 to 100 percent in fire ant populations, according to entomologist David Oi, at the ARS Center for Medical, Agricultural and Veterinary Entomology (CMAVE) in Gainesville, Fla.

Now, ARS scientists are looking to add a new scientific wrinkle: using the phorid fly as a vector for infecting the fire ant population with microsporidia.

Each phorid fly lays an egg into individual fire ants. These eggs later develop within the fire ant's head, ultimately causing its demise. But researchers tested a new method—infecting the phorid flies with a pathogenic microsporidia that controls fire ants.

Preliminary data showed that K. solenopsae was successfully transmitted to phorid flies without harming them. The next step is to determine whether infected flies are able to infect RIFA with the microsporidia, providing another mechanism for transmission between RIFA colonies.

According to Oi, K. solenopsae not only reduces fire ant colony size, it also reduces successful colony founding by reproducing ants, affects the survival of queens and increases the death rate of colonies.

Oi conducted this research with entomologists Sanford Porter and Steven Valles at CMAVE, and with Juan Briano and Luis Calcaterra of the ARS South American Biological Control Laboratory in Hurlingham, Argentina.

Story Source:

Adapted from materials provided by USDA/Agricultural Research Service.

enlarge

RS researchers are trying to make the phorid fly an even more effective biocontrol of fire ants by using the fly to spread microsporidia, a pathogen that damages fire ant colonies. (Credit: Image courtesy of USDA/Agricultural Research Service)

Related Stories

Nine To Twenty Individual Fire Ant Queens Started U.S. Fire Ant Population (Aug. 13, 2008) — The current U.S. population of red imported fire ants--which infest millions of acres across the southern states -- can be traced back to nine to 20 queens in Mobile, ...  > read more

Fire Ant-Attacking Fly Spreading Rapidly In Texas (Sep. 29, 2006) — Parasitic flies introduced to control red imported fire ants have spread over four million acres in central and southeast Texas since the flies' introduction in 1999, researchers at the University of ...  > read more

Fire Ants Killing Baby Song Birds At High Rates (Sep. 17, 2007) — Red imported fire ants may be killing as many as a fifth of baby song birds before they leave the nest, according to new research. Of the nests where there was no pesticide treatment protecting the ...  > read more

Fire Ant Outcompetes Other Species, Even In Its Native Habitat (July 14, 2009) — Even in its native Argentina, the fire ant wins in head-to-head competition with other ant species more than three-quarters of the ...  > read more

Search ScienceDaily

Fire Stopper