|
|
How to Manage Pests
UC Pest Management Guidelines
Turfgrass
Red Imported Fire Ant
Scientific Name: Solenopsis invicta
(Reviewed 6/03,
updated 6/03)
In this Guideline:
|
|
|
DESCRIPTION OF THE PEST
Fire ants are characterized by having a 2-segmented
petiole (the narrow waist between the thorax and abdomen), 10-segmented
antennae with a 2-segment club, and a stinger.
There are two native fire ant species likely to be encountered in California
that can be confused with the red imported fire ant. The more common one,
the southern fire ant (Solenopsis
xyloni) is 2.5 to 4.5 mm in length and found in coastal and inland
regions. It is very similar in appearance to the red imported fire ant.
The southern fire ant differs from the red imported fire ant in that it
is bicolored, with a reddish head and thorax and a dark brown abdomen.
By contrast, the red imported fire ant is an almost uniform dark reddish-brown
and 3 to 6 mm long. Both species have workers of mixed sizes.
Red imported fire
ant mounds are frequently built up into domes, while the
southern fire ant mounds are irregular
craters. Mounds produced by red imported fire ant can reach 10 to 12 inches in
height, however the size of mounds will vary with soil types, and mounds may be
absent. A characteristic difference between these species is the aggressiveness
of the workers. Although they will both sting, the ferocity of the red imported
fire ant is notable. Any object touching their mound is immediately attacked
and stung, and the workers will quickly run up a stick that touches the mound.
It is still uncertain whether the red imported fire ant
colonies in California have one or
multiple queens per colony. This could have a significant impact on the
selection of treatment strategies.
DAMAGE
Red imported fire ant can chew on soft plant tissue and growing buds. Their
stinging behavior can be hazardous to people and pets. Their sting is noxious
and produces a pustule on the skin
that can scar if it gets infected. They can clog irrigation lines and
short-circuit electrical systems.
MANAGEMENT
Although red imported fire ants are not present in all areas of California,
they are a serious pest and are subject to quarantine regulations. In Southern
California, state and federal officials have placed Orange County and portions
of Los Angeles County and Riverside County under quarantine that limits the
movement of
articles
including plants and soil. The California Department of Food and Agriculture
(CDFA) has established the Red Imported Fire Ant hotline (1-888-4FIREANT or
1-888-434-7326) to report any suspected occurrence of red imported fire ant in
California. This hotline is available 24 hours a day, 7 days a week to provide
current information on the red imported fire ant. An operator is available
Monday through Friday, 8:00 a.m. to 8:00 p.m.; after hours, callers may leave a
message. All calls reporting suspected red imported fire ant mounds will be
answered and the information will be referred to the appropriate agency for
response.
Biological Control
There are no commercial biological control agents presently available. The U.S.
Department of Agriculture and the University of Texas have begun the first
biological control program to control fire ants using a tiny South American
fly, called a phorid, that is a natural parasite of fire ants. These flies are
being mass reared and released in Florida and Texas for evaluation. Researchers
are also investigating other parasitic insects and even protozoa from South
America.
Monitoring
Presently, monitoring stations baited with Spam meat are being used at 50-foot
intervals to monitor for the presence of red imported fire ant.
Treatment
Contact CDFA or your county Agricultural Commissioner's office for information
on approved treatments. RIFA Hotline 1-888-4FIREANT (1-888-434-7326).
UC IPM Pest Management Guidelines: Turfgrass
UC ANR Publication 3365-T
Insects and Mites
H. S. Costa, Entomology, UC Riverside
R. S. Cowles, Entomology, Connecticut Agricultural Experiment Station, Windsor, CT
M. A. Harivandi, UC Cooperative Extension, Alameda Co.
J. Hartin, UC Cooperative Extension, San Bernardino Co.
H. K. Kaya, Nematology, UC Davis
Acknowledgment for contributions to the insect and mite section:
K. Kido, Entomology, UC Riverside
Top of page
|