October I977

Identification, Distribution, and
Biology of Fire Ants in Texas

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ural Experiment Station/ Neville P. Clarke, Acting Director/ College Station, Texas/ The Texas AGM University System

Contents

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5

Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Collection and Preparation of Specimens . . . . . . . . . . . . . . . . . . . . . . . . . 6

Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Key to the Fire Ants of Texas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Major Workers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 9

Minor Workers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10

Queens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Males . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 13

Biology and Economic Importance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 14

Red Imported Fire Ant (Solenopsis invicta Buren) . . . . . . . . . . . . . . . . . .. 14

Southern Fire Ant (Solenopsis xyloni McCook) . . . . . . . . . . . . . . . . . . . . . . 17

Desert Fire Ant (Solenopsis aurea Wheeler) . . . . . . . . . . . . . . . . . . . . . . . .. 17

Tropical Fire Ant (Solenopsis geminata [Fabricius]) . . . . . . . . . . . . . . . . .. 18

Black Imported Fire Ant (Solenopsis richteri Forel) . . . . . . . . . . . . . . . . . . 18

Spread of Fire Ants in Texas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Current Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Literature Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Acknowledgments

This study is supported in part by the Texas Department of Agriculture
Interagency Agreement IAC (74-75)-0448 and IAC (76-77)-0458. We thank H. R.
Burke and l. A. Jackman for comments on the manuscript and colleagues in the
Texas Agricultural Extension Service and USDA-APHIS for providing additional
information on the distribution of S. invicta. Thanks are also extended to l. W.
Summerlin, ARS-USDA, for assistance with field work.

Summary

Of the five species of fire ants recognized in the United
States, only four presently are found in Texas, with the red
imported fire ant (Solenopsis invicta Buren) now infesting
most of eastern Texas. Although efforts to control im-
ported fire ants have been a subject of controversy since
the U. S. Congress authorized a cooperative federal-state
eradication program in late 1957, these insects are ac-
knowledged as serious nuisances to both people and
domestic animals in the infested areas.

S. invicta, which made its appearance in the United
States in the Mobile, Alabama, area around 1930, has since
spread over nine states from the Carolinas to Texas. The
ants usually nest in soil in open areas such as pastures but
are found occasionally in wooded areas; mounds are gen-
erally dome-shaped. In man, the fire ant’s sting is charac-
terized by an intense burning sensation, accounting for
the popular name of ”fire ant.” Within a day, a pustule is
formed at the site of venom injection, which may become
infected. In some sensitive individuals, stings can lead to
swelling and occasionally death. In addition to its painful
sting, the fire ant’s large mounds can hamper the cultiva-
tion of land, and the fire ant itself can interfere with the
running of livestock, since it has been known to attack
small animals. S. invicta is considered to be the most eco-
nomically important fire ant species.

Although not yet comprehensively studied, S. xyloni,
the Southern fire ant, is also a ground-nesting species,
with nests sometimes being found in wood work or
masonry of houses. The nests in open areas are not
dome-shaped; soil is thrown from the nest in irregular
crater-shaped piles around the entrances. An immediate
flare, followed by a wheal, occurs at the site of a Southern
fire ant sting, but a pustule seldom forms.

The desert fire ant (S. aurea) is the least common
specie of fire ant in Texas, reported from only two Texas
counties. Nests are built in a fully exposed position in dry,
coarse, gravelly soil, under stones and dried dung, and
without a mound.

S. geminata, until the introduction of the imported fire
ant the most economically important fire ant in Texas, like
the other species usually nests in the soil. Mounds are not
generally dome-shaped, but some of them may be as large
as a bushel basket and as compact as those of S. invicta.
The reaction of humans to the sting of the tropical fire ant
is similar to that of the Southern fire ant.

Before the arrival of S. invicta, both S. geminata and S.
xyloni were very common in Texas. However, with the
westward expansion of S. invicta into Texas, both S.
geminata and S. xyloni have been gradually eliminated. S.
invicta appears to replace the two established fire ant
species.

Mirex bait has been an effective area-wide control
agent for the fire ant, but its use is now restricted. Hep-
tachlor and chlordane are two other pesticides currently
used to control the red imported fire ant; however, they
can be used only in limited areas. All are persistent chlori-
nated hydrocarbon insecticides and can be used only
where they will not constitute a hazard to wildlife, nonag-
ricultural commodities, or livestock. Heptachlor and
chlordane are not suggested for large block area treatment
of the imported fire ant. Research is exploring alternatives
to the use of these pesticides, including other insecticide
compounds, microbial control agents, pathogens, and
sterile male release.

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Identification, Distribution, and
Biology of Fire Ants in Texas

Akey C. F. Hung, Margaret R. Bar/in, and S. Bradleigh Vinson*

Five species of fire ants are pres-
ently recognized as occurring in the
United States. Much publicity has
been given t0 the two imported
species, Solenopsis invicta and S.
richteri, which are the subjects of all-
out eradication efforts by the United
States Department of Agriculture and
the various state governments con-
cerned. The native species, S. aurea,
S. geminata, and S. xy/oni, are of less
general interest.

The taxonomic status of S. invicta
and S. richteri has been subject to
considerable controversy since
Creighton (1930) first reported the
imported fire ant in the United States.
He suggested that the introduction of
the species may have occurred at
Mobile, Alabama, about 1918. This
form was recognized by the name S.
saevissima richteri Forel by Creighton
(1930, 1950). The species remained
confined to the Mobile area for about
10 years. lt consisted of only the dark

*Respectively, research associate, re-
search assistant, and professor, The
Texas Agricultural Experiment Sta-
tion (Department of Entomology).

KEYWORDS: Fire ant/identification/
distribution/biology/red imported fire
ant (Solenopsis invicta Buren)/South-
ern fire ant (Solenopsis xy/oni
McCook)/desert fire ant (Solenopsis
aurea Wheeler)/tropical fire ant (Sol-
enopsis geminata [FabriciuSD/con-
trol/research/Texas.

form, which is now known to corre-
spond to the southernmost geo-
graphic variant of the South American
population from which it obviously
came. The dark form (now known as
S. richteri) presently is found only in a
relatively small area in northeastern
Mississippi and northwestern
Alabama. About 1930, a light form
(now known as S. invicta) also made
its appearance in the Mobile area
(Wilson, 1958; Wilson and Brown,
1958) and has since spread over nine
states from the Carolinas to Texas.
Wilson (1951) suggested that the
light form originated either by muta-
tion within the dark form population
or by a second introduction. He later
provided further information to sup-
port the second alternative, suggest-
ing that the light form, which was in-
troduced into the Mobile area shortly
after 1930, is possibly a hybrid be-
tween two South American species, S.
saevissima saevissima and S. saevis-
sima richteri (Wilson, 1952 and 1953).
According to Wilson and Brown
(1958), the two color forms interbred
completely in the United States and
produced a graded series of inter-
mediate forms. They referred to both
of the forms as S. saevissima. In a re-
vision of the North American fire ants,
Snelling (1963) also used the name S.
saevissima for the imported fire ant
because the population in the United
State then consisted almost entirely of
the light form. Ettershank (1966) also
synonymized S. saevissima richteri

under S. saev/ssima, although he did
not discuss the taxonomic reasons for
such synonymy. Buren (1972) and
Buren et al. (1974) accepted Wilson's
double importation hypothesis but
further demonstrated (a) that there
are two morphologically distinct
species of imported fire ants in the
United States; (b) that these two
species have remained phenotypically
constant since the time of importation
and are unchanged from their parent
populations in South America; (c) that
the two species apparently rarely hy-
bridize; and (d) that their two home-
land ranges in South America are ge-
ographically distinct. Accordingly, the
dark form was recognized as S.
richteri Forel, and the light form was
described as S. invicta Buren (Buren,
1972).

Less than 50 years after the intro-
duction of S. invicta, multiple-queen
colonies were found in Mississippi
(Glancey et a/., 1973) and Texas
(Hung, Vinson, and Summerlin,
1974). These multiple-queen colonies
produce a high percentage of asper-
mic males (Hung et al., 1974), the sig-
nificance of which is now under in-
vestigation in our laboratory.

S. xy/oni occurs throughout the
southern United States from Califor-
nia to Tennessee and North Carolina,
with the exception of southern
Florida. In Central Texas the range of
S. xy/oni is overlapped by that of S.
aurea, an uncommon species occur-
ring in dry areas of the Southwest.

5

i! qie two species occur together
through western Texas, New Mexico,
Arizona, and southern California. Al-
though Gregg (1963) found a few col-
onies of S. xyIoni near Higbee, Col-
orado, the complete distribution of S.
xyloni in Colorado is not yet known.

The third native species, S.
geminata, as Brown (1961) and Wilson
and Brown (1958) indicated, is proba-
bly a post-Columbian introduction
from its original range in Central
America and northern South America.
In the United States, S. geminata oc-
curs from Texas to South Carolina and
is primarily found near the coast;
however, in Florida it appears to be
distributed uniformly over the entire
state (Creighton, 1950). One collec-
tion of S. geminata has been made in
southwestern Arkansas (Warren and
Rouse,1969)

Recently, a new form of fire ant was
found in the Bryan-College Station
area (Hung and Vinson, unpub-
lished); however, whether this is a
new species or a hybrid has yet to be
determined.

Thus, of the five species of fire ant
presently recognized in the United
States, four occur in Texas, with S. in-
victa (the red imported fire ant) now
infesting most of eastern Texas. Al-
though efforts to control imported
fire ants have been a subject of con-
troversy since the U.S. Congress au-
thorized a cooperative federal-state
eradication program in late 1957
(Brown, 1961; Coon and Fleet, 1970;
Ferguson, 1970; Long et aI., 1958; and
Reagan, Coburn, and Hensley, 1972),
these insects are acknowledged as se-
rious nuisances to both people and
domestic animals in the affected
areas. Fire ants are attracting attention
from physicians in the areas of infes-
tation as they become aware of the
medical problems associated with
stings (Brown, 1973; Clemmer and
Serfling, 1975; Lawrence et aI., 1973;
Lockey, 1974; Rhoades et aI., 1975).

IDENTIFICATION

Collection and
Preparation
of Specimens

The ideal way to collect fire ants for
identification is to disturb the mound
and then place a small object such as
a match stick on the mound. The agi-
tated ants soon crawl all over the
stick, which is quickly picked up and
put in a small bottle or vial containing
rubbing alcohol. Cologne or bay rum
are also used as preservatives but only
if alcohol is not available. Use of for-
maldehyde is avoided, since this
chemical is an irritant. As many differ-
ent sizes of ants as possible are col-
lected. A piece of white paper with
the collector's name, the date, and
the place (both county and nearest
town) in which the ants were col-
lected is included with the speci-
mens. All information is written in
pencil, since a ball point or felt tip
pen may smear or become illegible.

Figure 1. Ants mounted for identification.

lt often requires several hours for
ants in the alcohol to die. Before iden-
tification, the dead ants are placed in
a shallow dish from which specimens
of different sizes are selected with the
aid of a stereomicroscope. The
selected specimens are placed ventral
side down on a piece of paper towel
and the legs arranged symmetrically
in a standing position. The ants are
left this way until they are dry; the
drying is hastened by heat from a mi-
croscope's illuminator.

When the ants are dry, they are
mounted by gluing the ventral surface
of each ant to the pointed end of an
elongated cardboard triangle with
white glue and inserting an insect pin
through the other end of the triangle.
Up to three specimens from the same
colony are thus mounted on the same
pin (Figure 1). A minimum amount of
glue is used so that it will not conceal
parts of the ant necessary for identifi-
cation; ants are not mounted by plac-
ing a pin through their thoraxes.

Figure 2. Male (M), virgin queen (Q), major
worker (Wj), and minor worker (Wn) of S.
geminata.

Description

A fire ant colony usually consists of
workers, a nest queen (dealated), and
the queen's brood. A mature colony
may also contain winged males and
virgin queens (winged) (Figure 2) dur-
ing certain times of the year. Fire ant
workers can be distinguished easily
from other ants by their 10-
segmented antennae with conspicu-
ous Z-segmented club, unarmed
propodeum, 2-segmented pedicel
(the petiole and postpetiole), and the
presence of a sting, which may be ex-
posed (Figure 3).

Workers are polymorphic, varying
in length from 1.6 mm to 6 mm. Large
workers are called majors and small
ones minors, although intermediate
forms exist. Workers are wingless
with a simplified thorax; in contrast,
queens and males have two pairs of
wings. The male is markedly different
from the queen in several aspects:
smaller and more slender body,
darker color, smaller head, larger
eyes, smaller mandibles, shorter an-
tennal scape, longer and finer anten-
nal funiculi, and more conspicuous
genitalia. Queens usually break off
their wings after the nuptial flight, but
the thorax will still bear wing scars.

Methods

Identification of fire ant species is
facilitated if one is familiar with the
morphology of ants (Figure 3) and has
a collection of specimens, including
major and minor workers. The in-
struments needed for identifying ants
are a stereomicroscope magnifying
up to 80X and an illuminator which
will provide an intense ”spotlight" ef-
fect.

Separate keys are given below for
the identification of major workers,
minor workers, queens, and males,
using a combination of characters.
These keys are modified from
Creighton (1950), Snelling (1963), and
Smith (1965). Scanning electron mi-
crographs (Figures 3-20) have been
included to illustrate the key charac-
ters.

Measurements can be made with a
grid mounted in the ocular of a
stereomicroscope; only one eye
should be used when measuring. If a
character involves sculpture, illumi-
nation is important and the specimen
should be turned so that the surface is
observed at a 45° angle to the source
of light. Occasionally a specimen may
not fit all characters of either half of
the couplet, because of intraspecific

variation; if this occurs, the half of the
couplet with the majority of charac-
ters matching the specimen should be
chosen. Troublesome specimens
should not be discarded. They may
have scientific value and should be
sent to the Department of
Entomology, Texas A&M University,
College Station, Texas 77843.

KEY TO THE FIRE ANTS

OF TEXAS

Major Workers

1a.

1b.

2a.

2b.

3a.

Head bilobed (Figure 4, b) and ex-
traordinarily large, out 0f propor-
tion to remainder of body; man-
dible strongly incurved (Figure 4,
M), the teeth often largely
aborted or absent; anterior bor-
der of mesopleuron irregularly
lamellated or toothed (Figure 5,
MP.t); propodeum laterally cari-
nate (Figure 5, PR.c)  geminata
Head of moderate size, only
slightly bilobed (Figure 6, b);
mandible evenly curved (Figure
6, M), with three or four teeth;
anterior border of mesopleuron
smooth (Figure 7, MP.a), neither
lamellated nor toothed; pro-
podeum smooth laterally (Figure
7, PR.s) ............................... .. 2
Eye large and separated from the
insertion of mandible by a dis-
tance one and one-half times as
great as the maximum diameter
of eye (Figure 8); antennal scape
(Figure 3) length variable; petiole
with (Figure 7, P.t) or without
(Figure 10, P) ventral tooth .... .. 3
Eye small and separated from the
insertion of mandible by a dis-
tance twice as great as the
maximum diameter of eye; an-
tennal scape (Figure 8, S) failing
to attain occipital corner (Figure
8, O) by about the length of the
first two funicular segments (Fig-
ure 8, F.sg); petiole with distinct
ventral lamella (like Figure 7, P.t,
but extended two to three times
further .......................... .. aurea
Mesopleuron shining, at most
only weakly striated (Figure 7,
MP.s); petiole with anteroventral
tooth (Figure 7, P.t); antennal
scape (Figure 8, S) failing to attain
occipital corner (Figure 8, O) by
about the length of the first two
funicular segments (Figure 8,
F.sg); mandible with three teeth
(Figure 9, M), although a small
protuberance may be observed
on the superior border (Figure 9,
M.a, as opposed to four teeth
shown in Figure 12, M) ........... ..
.................................. .. xyloni

Figure 4. Major worker of S. geminata showing bilobed head (b) and strongly incurved
mandibles (M).

Figure 5. Major worker of S. geminata showing lamellated or toothed (MP.t) anterior
border of mesopleuron and carinated propodeum (PR.c).

9

3b. Mesopleuron dull, reughened, er
striated (Figure 3, MP, and Figure
10, MP.st); petiole without; an»
teroventral tooth (Figure it), P);
antennal scape (Figure “Vi, S} faili-
ing to ‘attain occipital ceurner (Fig-
ure H, O) by iess than length of
first funicular segrnent (as op-
posed to Figure 8, U}; (mandible
with four teeth (Figure “I2, M) 
 imricta

Minor Workers

‘la. Mesopleurien dull, roughened, or
striated (Figure l0, MPst}, with
anterior border irregularly lama-el-
lated er tnothed (Figure 5, MP1);
propndeum iateraily carinate
(Figure 5, Pliuc); petiole ‘lNilfhOLtT
vientral ttoloth or larnelia (Figure.
1U,  geminata

“lb. Mesopleurert dull or shining, an-
terior border neither lamellated
nor toothed; propedeum smooth
laterally; petiele with er ‘without
ventral teereth or lamellla............ Ii’.

2a,. Tip ref erntennal scape (Figure
“l3, S} surpassing occipital corner

  _ _. .i F’ 5M‘ k f5”! 'h' Fhtlizflbdtrdb cl l- cl
{Figure 13y U)! pvfitmhe Wlthznut nggtrigeiblgshmgprwor ero ryonrs owingsig y to e ea ( )an evenycurve

ventral tooth; miesopleuroh dull,

roughened, or striated (Figure 10,
MP.st, or Figure 3, MP) .... ...... . . ..


2b. Tip of antennai scape (Figure 14,
S) not attaining occipital corner
(Figure 14, O); petiole with dis-
tinct srmali ventral tooth (Figure 7,
P.t) or lamella frequently present;
mesopleuron shining or weakly
(striated 

3a. Eye with about 20 facets; petioie
with (ventral tooth extended
nearly the length of the segment
can-daily; body uniformly yeliow

 aurea

3b. Eyre with about 50 facets; petiole
with ventral tooth not extended
(Figure 7, P.t); gaster (Figure 3, G)
darker than rest of ibody............
 xylem

Queens

1a. Head, excluding mandibles, no-
taibily square (Figure 15); mandi-
ble abruptly incuiryed (Figure ‘l5,
M); antennal scape (Figure 15, S)
Figure F. Major werkrer bl’ S, xyllcini shrzrwing smeroth anterier ?border 0f rmescrpleurnn failing m reath Dcdpital 50mm
(MPai, rnes-epleuren rsmteutéh prweaicly striated (MR5); sm-Qgtéh prgprjdgum -(PR_,5)~ and (Figure '15, O) at least  time
petrole and anternventral teeth {P1}. ’ funicular Segment  gvgmmata

“l0

1b. Head, excluding mandibles,

2a.

2b.

3a.

3b

weakly heart-shaped; mandible
evenly incurved; antennal scape
reaching or surpassing occipital
 2
Posterior two-thirds to three-
fourths of propodeum distinctly
transversely striated (Figure 16,
PR.st); node of postpetiole
striated on its posterior half (Fig-
ure 16, PP.st); mandible with four
teeth as in Figure 12; antennal
scape surpassing occipital
corner; petiole without ventral
tooth (Figure 10,  invicta
Posterior one-half or less pro-
podeum with transverse striation;
antennal scape at most reaching
occipital corner; petiole with
tooth; node of postpetiole with
transverse striations indistinct or
absent; mandible with three teeth
Light yellow color, ventral tooth
of petiole extending nearly the
length of the segment  aurea
Dark red color; petiole with
ventral tooth. not extended (as
opposed to Figure 7, P.t)...........


Q

Figure 9. Major worker of S. xy/oni showing 3-toothed mandible (M) and location of
superior border (M.a) where a small protuberance may occur.

Figure 8. Major worker of S. xyloni showing
antennal scape (S) failing to attain caccipit-ail
corner (O) by length of first two funicular seg-
ments (F.sg).

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Figure 17. Male of S. invicta showing dis-
tance between lateral and medial ooelli
(y == 2/3 x or > 2/3 x) and convex clypeus (C).

Burleson

Caldwell (Lockhart)
Calhoun

Camp (Pittsburg)
Chambers
Cherokee

Collin (Plano)
Colorado

Comal

(Cooke (Valley View)
[Jallas (Richardson)
Benton (Lewisville)
Dewitt (Yoaku m)
Ellis (Ferris)

Eratli

Fialls (Chilton, Lott)
Fayette (l_a Grange)

lifio rt Bend
lFreestone (Teague)
Frio

Galveston

Gillespie (Harper)
Uoliad (tannin)

i

,._-_.__. m

Figure 19. Male of S. invicta showing broad and deep mesosternal suture (MS).

Gonzales (Waelder)
Grayson

Gregg

Grimes (Anderson, Navasota,

Plantersville)

Guadalupe (Seguin)
Hardin

Harris (Houston)
Harrison
Henderson
Houston

Jackson (Edna)
Jasper (Jasper)
Jefferson

Jim Wells (Alice)
KendaH

Kerr

Kleberg (Kingsville)
Lavaca (Hallettsville)
Lee (Giddings)
Leon

Liberty

Limestone

Madison

Marion

Matagorda (Bay City, Pledger)
McLennan

Medina

Milam

Montgomery (Conroe)
Nacogdoches
Navarro

Newton

Nueces

Orange (Vida)

Panola

Polk (Livingston)
Refugio (Tivoli)
Robertson
Rusk

Sabine

San Augustine
San Jacinto
San Patricio
Shelby

Smith

Tarrant

Travis (Austin)
Trinity (Trinity)
Tyler

Upshur (Big Sandy)
Uvalde (Uvalde)
Victoria

Walker

Waller
Washington
Wharton
Williamson
Wilson

Wood

The biology of S. invictla Buren has
been studied extensively since this
species is of considerable economic
importance (Lofgren, Banks, and
Glancey, 1975). The ants usually nest:
in various types of soil in open areas
but are found occasionally in wooded
areas. The larger mounds in open
areas are generally dome-shaped
(Figure 21) with numerous galleries
and chambers; when these mounds
become compact, they may damage
or affect use of farm implements. A
colony is usually started by a single
queen; however, Markin, Collins,
and Dillter (1972) found some incipi»
ent colonies in Gulfport, Mississippi,
containing two to five queens. ln
addition, mature multiple-queen col-
onies have been reported from
Mississippi (Glancey et al., 1973) and
Texas (Hung et al., 1974). After the

Figure 20. Male of S. xyloni showing narrow mesosternal suture (MS).

nuptial flight, the queen alights on
the ground, breaks eff her wings, and
begins to excavate a brurrnw within 4
heurs.  lays her first eggs within
24~48 hours after Completing the hur-
row. The entire oleeelepmental time
ire-m egg clepcmtion to emergence of
the ‘first tiarorker {leiten reierred to as
minim swerkers) is alaout 1243i] ‘days
‘for nattmrallty oreriurring tiTtiiltlittitiitfi and
EUaEti days fer iialariiraytory rttellonies
held at Etizfiiiif tie lirtimf. tiviilt-"iidiiiidliinl  aig.

tiliQiFEt. m.tfi'pli'tf.ll=tiil-l.iltillii‘itté forms are pro»-
elueeti‘ ‘veiihin 5 tn "ipli n1!o»r"t~th1s, rzleprenol-
inlg nan the relinrrate.  ttlttlrirfitlltiltit mast anon»
trai n as mange a s Enid ,nt]1ti~ ir-tittllitiiltifilltdi after 3
iyears. nltene-iugihl hroio-tl  =r*-edluettiilen es-
rsentiaille rireasies. in  i~iiiinttier in areas-
nerth not Lit?!“ attiitrtuoie,. terrified lhays thee-n
‘ion u and in srowrne lntiorutn-d s ii'illi"ilii“"llff»lll.i;g.i’ll~liilrl.ii'
the year in i: e n t: aria. ii ainud sreruitihiirn
Florida and i n lifiilitdlJfiilild. i: e- u: n t ii ares in
Teena s .  u ptii a all fiilliii  ‘its lnraiiivai rh-lewertl
n oted rewertr ililiilillli'll'ill"ili"il in 7lli1.lll'i>iid5~ii' liFH/iillliiitfrll"
areas ,: ino’~.~sretirelrg,. iueailt. .a;tri*ttiiiiiiii ilfiitlilitiilittiilitfi-
hirer tTt late  reruigih:  iitdhl
 s utlnsreurutent; "the ttline iitititdrltilllritiliridlitiil elect‘ lhi
est nrodturcrtien  uaill ihltntilieidl illi-iiillritziillirlidllllir"
l:  n et at. o, “l diittl  . iilllilhrtirs. gpeirm lliliiiiillllillliii“
eceu r ‘ire nrl n-e~~e-lznl "tite-  in llillill "li-iliitillilllIilliltilll n ‘ii ttirel
2 rdlairs attler a araini ie<stilnte~irziiiailllllfgii iii“ tilllriie
rai n iwas lzieven pittittilififird ed ltirigir  |eiewlréiiielidi nit’
idry seeatiher. nilttihiiulglhi liililliliiEllillIiilliiillli ‘iiiiiiitigjiihitl:i:s;
roan take placate int aitrgir  illiiilil llllillillilEt*
‘itear in Texas, the heart: teens iitltiirlellnlwsi rti~ni»lr'
s u r: ic e s st u l [so l o nrir e is ta.  i  s. n liiliiil e ill”!!! 
ocour between inn  anr Ereieirtle-nnhie-tr.

 

   

 

The prime re diet nil tiire flllliilillifii is inn
sects, spiders, méirrianiedis,. tifiairillitr»
werrns, and rlililiilifii‘ small ineeirtellzilratiezs
ifireen, WIN; Hairs and l-iayrs, 
Wilson and Earns, ‘T949; Wilsern anci
 inner, “iijiedi; iioiieevrerr, they are alse
kno-‘wn tie "ieed en earrinn and are an
tracteel rte scugar and hoinsery-die w. Feed
is eoliectaed he time ieraging; WUFiQE;FS.
TilhEEWE‘ workers often ileawe ttihre ifllifliuiitlli
tlirnaluggn “tunnels which may eetienel as
tiara as ‘i525 m trons the meunid at a
depth of i5 tn “i2 mm. Unite feted is
fennel‘, tine tiorragesr rretulrns to the nest,
laying a en-ernicall iohierionntginiei trail
which wnrlizeirs sulaseeluenttlet tedllew
irolni tine nest to the ironed souroe.

nii stinging, insects, with the EittEEFt-r
tien rot iire rants... ultiilziae a veznem ritn
in nrietein. lithe erenom oi tire ants is
runicgtue in isnntaining allitalroi~rzls wraith a
ifflildiliiiiiiifiiiiilti snrialil airnountt ‘oi [aroteiln
{Brand e~t aim. “twill.  iresnorn is
use-d to nnirrnoihiiliaie or iziil spree fer

"in

lFigure 2i. a. densle-shaped mound of 5. invicta.

“tieieiidi; in addiittion, it QCIYSEESE-ELS insec-
tirlti-draii, lina-rcrtieartirttiiizliai, and fungicidal arc-i
 tlfhtli u lliiiil et all ., 1 dEidIi . “it‘lr”§h~e' n st i nig-
iilnig. lh~e~ ir"'lt~‘”U¢i"lll'-T.lETl°' attaishies to its p reigr
"iiili““il'iili'ill i lririiaianiltililes. and tlh en tioiettezs the
Eiiiililiidlgtg; illliiilfltlli the tilts su e tlFi gu re E2}  l n
irnainl ililiiltllfi illlllilliliiiillltfitifiilillfllfiiifi’ reactiorzn to t he
illllliilllllltiiZtiCllirllEtliZii een~nlntl is an intense hurrning
sienna aitiiowni "lriirtlill iitih HECU u nits tor th e
liltrlilfitlltiillliéilli” nanile oi “iiire lant.” A terse
irleii n utveas liatttier a eai appears at the
sitttie oti the tirennni i ngieittion, land a p~us-
‘tluléle is ‘ii-nlirmed within a tevr hours
iIiFiiglljlifiE‘ Edi. a. tent individuals may

 

 

Figure 3.2. An intiporteci‘ ‘fire ant worker

stinging a hruiman fiiinger.

have systemic reactions including
nausea, vomiting, dizziness, perspira-
tion, cyanosis, asthma, and other
symptoms typical of severe allergic
reactions. Death can result in a severe
case if no medical assistance is re-
iceived (Tripiett, i973).

Figure 23. Pustules formed as the result of
imported fire ant sting.

Southern Fire Ant
(Solenopsis xyloni
McCook)

This species ranges from California
to North Carolina and the northwest
corner 0f Florida. It has been re-
ported from the following counties
(and towns) in Texas:

Bee (Beeville)

Brazos (Bryan, College Station,
Millican)

Crockett (TAMU Sonora Research
Station)

Dallas (Kleberg, Dallas, Carrollton,
Duncanville, Garland, Grand
Prairie, Huitchins, Mesquite,
Richardson, Rowlett, Sachse,
Wilmer)

DeWitt

Eastland (Ranger)

El Paso (El Paso)

Falls

Fannin (Bonharn)

Frio (Pearsall)

Galveston (Galveston)

Gillespie (i iarper)

Goliad (Goliad)

Grayson (enisort)

Gregg (Longview)

Harris (Houston)

l-lendersron (Athens)

lasper (jasper)

Jefferson (Port Arthur)

Kimble)

Madison

Matagjordia

Morris (aingerfield)

Miavarro (Corsicarta)

l*~iolai"i (Sweetwater)

Mueces (Corrpus Chrisiti)

O range (U ra n ge)

Partlser (Weathlerford)

Polls

Presidlo (Presidio)

Red Riser (Clarksyirlle, Detroit)

Refugio (Riefugior)

Rooter rtson (  ea rn e)

Smith (Tyier, iirolurp»)

Sutton (TnMiJ Sonora Research
Etaitiion)

iarrant

Taylor (nhilenle)

Uoshur (We Sandy)

lJtralde= (ldsaaldief)

‘it/an: Zandt

Victoria. (lriettorlaj)

Was  ngton

Wiehita (Wiehita lallsr)

Wood lldiilllildillil

 

 

A comprehensive study has not yet
been undertaken on the biology rot 5.
xy/oni. Like S. int/iota, it is a ground
nesting speeies, althoiugh nests (are
sometimes found in woodwork (or
masonry of houses. The nests  (open)
areas are not dorneshaoed; soil is
th ro wn trorn the nest in irregular
cratershaoedi piles around the
entrances (Figure 24). a  Wide
rnoimd eontainlng; at least 4t nest
openings has been reyoorteld 
1958). Newly rnated ouieens estalolish
colonies. lndepenoenrttly in  soil
(Smith, 1965), and althraurglt single»
queen eololnies are the rule,
Ffllillillplfi~tl|ljififiifl eolonies itaye been
iounrd (Sunanterlin,. W76). (‘nuptial
flights have heen nroted frorn. June)
th roe gh Seotetrnbte and -oeieu  r orirnairr)
ily in the late afternoon. this soeeies,
like» S. invieta, is a general) tel-elder).

The yenorn: of  sylToiti eshiloits 
same Blrllilllllllltlfifllilllfi’ and .a niiti(ih as.t erial
properties as the yenorn f inyieta,
bot the slrin. response oil rnan taro the
stings of iliillwefi e (into) soles) es is different
(Blusrn, Rorherts, and Littler-trials.  
intermediate tlare, tollowedi lhyr a: srlh eal,
oer: u rs at tire site of sensor liltljlfitfillitilll”)
by  xyioni, hurt its rig seldoirn 
suits  pustule forrnraitiloln.

[Desert Fire Ant
(Solenoosis area
Wheeler)

ans regirans (at  fitiitilllwtttsl irstattt 
"(esas to sou t:her n tlfaliftsntiia, tltiitllll
intro  are the ggienerral rtnlgta rill
d. sures» in Trasas, it ltas laeert 
ported lftjlil) nustin ("irayls 
and Frart  (Jeff [fiat/is (lirtlsuitrty).

 auirela  this least retalnirnrtirit
soeeies (of tire ants.  is linen/rt rial
its I oi1r;i l?org} y. "Thee ants a;u u ts.a r to  newts
turnal or sreotisstiliar,   
are usually)  in a ftilly 
posltirln in dry, t:r;larsye, g,rriay ~e)|I?y sttiil.
under tlltifitltittzl»  drisiel dung, anrd
yyitrrout: a rnlelu .  are) itisrtsly
found o utsie the. nsist: dlurin  slay
and will alrnostt iinante d iaitita l iy 
pear inter    oil traits:
 Wlldll s.    l 
  .  
a |:i\((a)a.r)e ntll%iy l s not; e~sorntarnrieallyr rn



 

 

Flguire-  tsierst. oi s syrlonti‘ ssiitih rreiyguiliairi eirairtire-irsr.

ll Til")

Tropical Fire Ant
(Solenopsis geminata
[Fabriciush

This species cuctturs front Texas to
South Carolina and Florida. It has
been reported from the iolloyying
counties (and tiin-y-nsi in Texas:

A ran sas
rktasttiista tflnurdanttin, Pleasantoni~
ietistirw ifiellyillel

Better {San ientonitai

Blanco

Braaoria innglettary. Freeporti
Braatis iliirytan. College Stationi
Burleson tfaltlxiyelll Dime Btisji
Camertm ‘lBTttV\i“F1S\llllllli:‘,. l-ilarllingeni
tint a l’ i New Brau niiells ‘i

Ctirytelll ttiiiatesytillleil

lit-atlas  Earr»ta~ll'tt:i=ni_,. Eoiplpiell

Grand Prairie. Iryin;g,,. ltantcasiteir.
Dali agoyiillleyi. Riichaindrsronli

Falls titottil

Fayte-tte iLa Grangwei

Fo rt Bendi lRllElW mondljiil

Fri Iiliiearslalllllt

Giallwtast on t’  al ‘reslt-o-n it

G ll ill ll esp lie-

Gtinaales: i‘ Erona-allesil

G uiadall u  lLSe-gu i nil-

lhl-arrliis lllhlttlltlliSilliltllillll

lleliayls iEian ilvtarcttilsi-

H ii ll dia ll g-o i, lEdl ii in b u rgffil

_.liaii:lltsrerln iyltdlniajil

illeii mllalllltlllllls» iiFort lfltlaittisjil
llieiie-rstin ‘llB~'E\dlllllill’li‘ll1illill|llllll‘

ll ii rn “tiiilellll tel iceil

li(~e~nie~~dl‘y~l

liilerr i; lite-trait ll ll e i»

ltilleilbieryg llllRlilll‘llg‘5~lii"llillll'E' liitiitiliieririajfl
ltarnlar tliiariislft

ta niipialsas t ltannrpraslasifiti

tattlaica lllilltlltlallltlui nail

lLe-et i ltertlinigtiatlniii

ltlialnio- i licllilaniofi-

ihtiataigwo-ndia tlhay‘ "Eiitiit li-tllie-ldlgretrii
ihtireitenlniani illielhluiattwainla "Erie-revisit
htrettlliiilan Illiilaniisiir

.l\iiliiiillarn|

hit-or rii i, llIta ii nig; e riiii re ll dill

iNl u leteets

iReailll

lltt»eilu;gjiiiliot

Rioihrertsrnrln

i5ani= iFtaitriiitii-iail ii-‘iirlanislias. ilPtaisiesfi
Stain» Sraha

illitatt‘ lllllS ll,cili,,li.iiiislllttlli in: l‘

lLlllliildillllljlllllfi“ i,ldtriwiaillittllreii

ltlalll lltlieilrldie- Iillllllieilli third. lkiiallllivnlllglyllllwllliillllll

feral

Victoria (Victoria)
Walker (Huntsville)
Washington (Brenham)

Until the introduction of the im-
ported fire ants, this species was not
only the most common but the most
economically important fire ant in
Texas (Clark, 1931i. S. geminata usu-
ally nests in the soil; the mounds are
not generally dome-shaped, but some
oi them miayt be as large as a bushel
basket and as compact as those of S.
iny-"icta. No detailed studies have been
made ran the biology oi this species.
Colonies usuallly contain a single
queen; hoiiveuier Ban lks, Plumley", and
Hicks {i973} reported two fertile
queens in one colony of S. geminata
in Florida, and nniultiple-queeni col-
~o»ni~es haiwe been found near Victoria
anial irtioiodslimortt and in tine Bryan-
Eollleigxe Station area il-iung. Linpub-
lislhedlji. ietccoirding to~ Trait-is. IifilEi-tijjlq,
"Iiifljlllilhliii" Iituteens laid as ntanry" as ilfllE3
eyggs in a ‘It-ti-hou r pie riodl andl iwtorkers
"tittlEFlEl reared to tlhe~ adlult stage in 
diary-ls at slunrnirer tenrrpieratlures. l-le re-
plotted that in niaiirtlhiern lFlloridla and
southern tlieiolrgila StEii-Itlllétll larvae ap-
prelareid in tlhie nrotu n-ds in early eipril
and tliiat allate i-ornis lttterie p-r-esent in
 ioienzenit oti tlhe coilioinies. up to the
en dl ori lD~e~~rc e rni lb e r .. ll n the Brittan-
lC-ioillillietgie Statii o» n areia alllate iorms ‘titre re
lttilllllllllllliE“'l:llilE“l|Elll nrriailnlly" iiln illlhlllliallill tlhiroiug hi ilullyn.
and mllll-Jllpllltllltallll illliiglhts loceuiririingy in the
llatie aite rnrotoini hawte- lbe-len notedl in
these» irniolinitlhis... ‘lllh is sipteciieisy. lliillte the
iotlhers is a glenreiriall ieeidler" preyting
ptrriinniairiiilllfiir‘ ran ra-tlher lllllFliI§iE““ll:lll§ anti innter-
llitdllillltliiifll llliElYS ..

llilhie- liiElHlllfllilllltlilltllllli ia-il llrruinnian s to~ the sting
»oi tlhrlis I5li-ll"'E“‘iL“llllllE“‘§i ii inelnyy" 1sii=inrriilllar to that oi
 it‘;tilt"Iillllillililllllillltt as "U"lpl“|l;lll'|lilll1SiiE“ldl to that oi S. iln-
iittiiiiiclta... lit has raisin lhtee-ln ‘Silliliflltlrlliilrli experi-
lllilliltli“lilllilll-Hlllllllllliil‘ tllhrat... ilni ilF-"niilerirt-ol lltliittlni ‘lkmtimfkfllfs.
tori  giieinnliinialtiai inani txairl  ‘nriiallsille ‘gernts
rsrti HldlllllillSiti?“lli7lllll'lE‘li“"lliil" on- tlhiieiir lfiillifltflllllES ini- at
lllieairslt  llllfillllllmlllllllllllifllsl iilU llmlllllilllllllllllllllii5 ii “Ett-‘llitllil.

ihiilllaitillt ilnrrllypio-irtrerol tire stint
iiliSiioiiilll en loiip-isiii s lll"lllil:ll'illl'Eil“lll
iliilialltiineiillfill

lllllllllllllillllilh llllllllilillliiiitltttiflllliiltllllifillillll [Silipiliiii-lttfi’lllilHEi i1| 5 lll-lulllwinild mnlltri‘
iilirri lat lrrellllal  illiii" rsnrriiailllllll ifliliitlitfill in niortlheiastl-
tellrilttll lit»?  l ilqipiiii a nirtll no rt lhiwtwe-ste rn
ii‘“lllmllliiiillillilllifillllllitilliliilll.i. "tliiiillllriiiillilire lhllttlitlll pirietsle-n|tllliyt' ioluinid‘
llllilililil ilrettrats»_... lit: ills iinil-rollluirdletldll t-o looniypiiiiigtte

   
  

the species list in the United States.
The biology is not as well known as
that of S. invicta but appears similar in
many respects. Workers of S. richteri
will key out as S. invicta in the keys
described herein. Buren (1972) gives
the following characters for separat-
ing S. invicta and S. richteri:

"In richteri the sides of the head are
usually broadly elliptical in shape and
lack the weakly cordate shape seen in
invicta; the peaks of the occipital
lobes nearer the midline and the oc-
cipital excision more creaselike in
richteri than in invicta in relation to
their ability to reach toward the occip-
ital peaks; pronotum with strong and
rather angulate shoulders in richteri,
this character nearly absent in invicta;
a shallow but distinctly sunken area
on posterior median dorsum of the
pronotum of large workers in richteri,
absent in large workers of invicta; the
promesonotum strongly convex in
profile in invicta, more weakly so in
richteri; in profile the base of propo-
deum elongate and straight in richteri,
convex and shorter in proportion to
the declivityr in invicta, the postpetiole
wide and with straight or diverging
sides posteriorly in invicta, narrower
and usually with converging sides in
richteri; transverse impression on
posterodorsal face of postpetiole
usually apparent and strong in
ricihteri, usually weak or absent in in-
titicta.”

SPREAD OF FIRE ANTS
IN TEXAS

Before the arrival of S. invicta, both
S. geminata and S. xy/oni were very
common in Texas. S. xy/oni was the
most common fire ant in the eastern
half of Texas, while S. geminata was
confined more to the southern or
coastal section of the State. However,
with the westward expansion of S. in-
victa into Texas, both S. geminata and
S. xy/oni have been gradually elimi-
nated by S. invicta. For example,
Smith (1936) reported S. geminata and
S. xy/oni at Houston, but the two
species have now generally been re-
placed by S. invicta. ln 1973, the au-
thors found both S. geminata and S.
xy/oni side by side with S. invicta in an
area along the bypass east of Highway
6 in College Station. These areas are
now exclusively inhabited by S. in-
victa.

The past and present distribution of
the four species of fire ants in Texas is
illustrated in Figure 25. These county
records are based on specimens iden-
tified by one of the authors (A. C. F.
Hung) from the literature (Creighton,
1930; Hess, 1958; Smith, 1936) and
from Extension and USDA-APHIS files
(S. invicta only). Whereas the distri-
bution record of S. invicta might be
complete because it is compiled from
current data, those of S. geminata and
S. xy/oni are by no means adequate.
Although the records reported are
current, new counties may become
infested as S. invicta continues to
spread through Texas. When S. in-
victa moves into new counties, it ap-
pears to replace S. geminata or S. xy-
/oni. Because of the similarity in their
ecology, it is likely that S. invicta will
eventually move into those counties
where the other two species of the
fire ants are presently found.

CONTROL
Current Methods

Heptachlor and chlordane are used
to control the red imported fire ant in
limited areas: nurseries, industrial
sites, lawns, golf courses, cemeteries,
parks, and other restricted nonag-
ricultural and nonaquatic areas. Both
materials are persistent chlorinated

hydrocarbon insecticides and can be
used only where they will not consti-
tute a hazard to wildlife, nonagricul-
tural commodities, or livestock.
They are not suggested for large block
area treatment of the imported fire
ant.

ln the granular form, heptachlor
(1.25 pounds per acre) and chlordane
(1.0-1.5 pounds per acre) are used as
broadcast soil treatments. Individual
mounds in lightly infested areas are
treated by applying either chemical to
the individual mound. The mound is
torn open and 1-2 cups of dust
granules containing 10 percent chlor-
dane or heptachlor are applied to the
mound and the ground within a 10- to
12-foot area on all sides. Chlordane
emulsifiable concentrate (4 pounds
per gallon), at 4 tablespoons in 3 gal-
Ions of water, or heptachlor emulsifi-
able concentrate, at 8 tablespoons in
3 gallons of water (2 pounds per gal-
lon), is used to thoroughly drench the
mound and surrounding soil. Treated
areas are examined within 3 weeks
and surviving colonies retreated.
These insecticides are most useful on
the cooler days of spring or fall and
winter months. County Extension
agents or Extension entomologists
should be consulted concerning the
safety and advisability of treating a
specific area.

All suggested chemicals must be
registered and labeled for use by the
U.S. Environmental Protection
Agency and the Texas Department of
Agriculture. The status of an insec-
ticide label is subject to change. Such
a change may have occurred since
printing of this publication.

The insecticide user is always re-
sponsible for the effects of the pes-
ticide used and the resulting residues
on his own crops and livestock, as
well as problems caused by drift to
other properties, crops, or livestock.
All label instructions should be read
and followed carefully.

Research

In the late 1940’s granular hep-
tachlor was the most common insec-
ticide used for the control of im-
ported fire ants. Hays and Arant (1960)
developed a bait concept for control,
consisting of a toxicant in peanut but-
ter. They reported that Keponef} was

an effective toxicant applied as a bait.
Lofgren, Stringer, and Bartlett (1962),
Lofgren et al. (1964, 1967), and
Stringer, Lofgren, and Bartlett (1964)
further developed this method using
mirex as the toxicant.

The first aerial application of mirex
bait for area-wide control was made in
the fall of 1961, with excellent results.
For more than 10 years mirex bait was
the standard control agent for fire
ants and is still the only known area-
wide control effective against the im-
ported fire ant (Alley, 1973); however,
the long environmental persistance of
mirex, which results in bioconcentra-
tion in the environment, has received
increasing criticism (Baetcke, Cain
and Poe, 1972; Naqvi and de la Cruz,
1973; Wolfe and Norment, 1973;
Summerlin, Hung, and Vinson, 1977).
ln addition, it accumulates in the fat
of animals, including man (Gibson,
lvie, and Dorough, 1972; lvie,
Dorough, and Bryant, 1974,- Anony-
mous, 1976, Kuty et al.,1974), and as
one animal eats another, mirex is ac-
cumulated in its body. Mirex will also
stimulate certain enzyme systems
which affect an animal's susceptibility
to other chemicals (Baker et al., 1972).
For these reasons, the use of mirex
has been severely restricted.

An alternative toxicant for control
of fire ants has been sought for the
last 10 years. Lofgren et al. (1967) de-
scribed a screening technique for tox-
icants effective against imported fire
ants and reported laboratory test re-
sults of 334 compounds; however, no
new compounds were found to re-
place mirex. Levy, Chiu, and Banks
(1973) and Wojcik et al. (1973)
suggested additional compounds as
potential control agents, but none
were found to be as effective as
mirex. The reason for the success of
mirex is that it does not rapidly kill
food-foraging worker ants that eat it.
Also, mirex is not destroyed by the
stomach (crop) of the worker ant. The
worker can carry the mirex back to
the colony and spread it around by
feeding other ants before it dies.

Most potentially effective com-
pounds kill too rapidly (Wojcik et al.,
1973), although a group of chemicals
called “insect juvenile hormone
mimics" appear to have promise.
These chemicals do not kill adults but
kill the immature forms before they

19

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i XYLONI

Figure 25. County distribution records of fire ants in Texas.

2O

 

SCALE

l0 Z0 30 40 50 60 70 B0 90 IOOHIIIS

develop into adults. The compounds
were formulated in an oil base bait
and were found to be effective against
small laboratory colonies of imported
fire ants (Cupp and O’Neal, 1973;
Triosi and Riddiford, 1974; Vinson
and Robeau, 1974). A rapid screening
program was developed and a
number of compounds were
screened for activity (Vinson, Robeau,
and Dzuik, 1974), but the effective-
ness of the compounds in the field
was erratic (Vinson, unpublished).
These erratic results were explained
when it was discovered that the
juvenile hormone was destroyed by
the foraging worker ant so that very
little was fed to the larvae (Wendel
and Vinson, unpublished). Further
work revealed that the juvenile hor-
mones may be effective if they can be
placed into a mound; for example,
when a few larvae are treated with the
hormone, the chemical is spread to
others (Wendel and Vinson, unpub-

lished). Recently, a brood pheromone
was identified (Bigley and Vinson,
1975) that stimulates workers to carry
materials into the nest. By mixing the
pheromone and hormone, both ma-
terials were conveyed into a mound
of the imported fire ant (Bigley and
Vinson, unpublished). lt is hoped that
this approach will lead to an effective
area-wide control without use of in-
secticides.

Other control methods have been
and are being explored. Bacteria of
the genus Pseudomonas and the
three fungi, Beauveria bassiana,
Metarrhizum anisopliae, and Aspergil-
lus f/avus, have been studied as mi-
crobial control agents (Broome, 1973;
Sikorowski, Norment, and Broome,
1973); and recently, Allen and Buren
(1974) isolated the microsporidian,
Thelophania sp., from S. invicta col-
onies in Brazil. There is no evidence
that any of these pathogens have ef-

fectively reduced infestations of fire
ants. The role of predators and insect
parasites in regulating populations of
imported fire ants in the United States
has also been studied (Hung, 1974;
Lofgren et a/., 1975; O'Neal, 1974;
Silveiro-Guido, Carbonell, and Crisci,
1973; Whitcomb, Bhatkar, and Nick-
erson, 1973; Williams et a/., 1973;
W. F. Buren, personal communica-
tion).

Sterile males of S. invicta were
found in field populations from Col-
lege Station, Navasota, and Anderson
(Hung et a/., 1974). The frequency of
sterile males was as high as 100 per-
cent in some colonies examined.
Additional populations with sterile
males have been found at Huntsville,
Stephen F. Austin State Park, Pledger,
and Varner-Hogg Plantation (Hung,
unpublished). The possibility of using
male sterility in genetic control of fire
ants is now under investigation.

21

LITERATURE CITED

Anonymous. 1976. Mirex found in 409i. of certain human
tissue samples taken by EPA. Pestic. Chem. News July
14, 1976. p. 26.

Allen, G. E., and W. F. Buren. 1974. Microsporidian and
fungal diseases of Solenopsis invicta Buren in Brazil. J.
N.Y. Entomol. Soc. 82:125-130.

Alley, E. G. 1973. The use of mirex in control of the im-
ported fire ant. J. Environ. Quality 2:52-61.

Baetcke, K. P., J. D. Cain, and W. E. Poe. 1972. Residues in
fish, wildlife and estuaries. Pestic. Monit. J. 6:14-22.
Baker, R. C., L. B. Coons, R. B. Mailman, and E. Hodgson.
1972. induction of hepatic mixed-function oxidases by

mirex. Environ. Res. 5:418-424.

Banks, W. A., J. K. Plumley, and D. M. Hicks. 1973.
Polygyny in a colony of the fire ant, Solenopsis
geminata (P). Ann. Entomol. Soc. Amer. 66:234-235.

Bigley, W. 5., and 5. B. Vinson. 1975. Characterization of a
brood pheromone isolated from the sexual brood of
the imported fire ant, Solenopsis invicta. Ann Entomol.
Soc. Amer. 68:301-304.

Blum, M. 5., l. E. Roberts, and A. F. Novak. 1961 . Chiemi-
cal and biological characterization of venom of the ant
Solenopsis xyloni McCook. Psyche 68:73-74.

Blum, M. 5., l. R. Walker, P. S. Caliahanr, ancl A. iF. Not-talc.
1958. Chemical, insecticidal and antibiotic properties
of fire ant venom. Science 12.8:306-307.

Brand, l. M., M. 5. Blum, H. M. Fales, and ll. C. i‘~.-t..a.cCJonr-
nell. 1972. Fire ant venoms: co:m:pa.ratii.re anialy-"s-is of
alkaloidal components. Toxicori 10::.25’9-.27 

Broome, J. R. 1973. Microbial control of thle imiiportetzl fire
ant, Solenopsis richteri Forel. PhlD tyhesis. itvtiiss... Staitie
Univ., State Coliege, Miss.

Brotvn, L. L. 1973. The physician and fir-e anrts. l. 5.115.. llllIn"lllli'E‘lll:lt
Assoc. 69:322-324.

Brown, JiN’. L., Jr. 1961. Mass i insect control ltrropgirairinisz: lF-oiurr
case histories. Psyche 6~8:7]5~-1l09"..

Buren, W. F. 1972. R-evisionairy: stodiies. on tihie t.a:ii:oinio itiili
the imported fire ants. l. Ca. Einticrmioil. fS-oi-cr. Ti“::1l--'.2f.'-:‘”.
Buren, ‘tN . F., C. E. Allerii .. lHl. li-li-"ltiliit»ct-o~|rinibi F.  Lian-
nrartz, and R. N. trtiilliams. 119174.. EIIIIJHICIIQQEWIJZIILgiliflllllltlllllfli‘ waif "tilt-e

imported tire ants. l. H.111. Eint-om-oil.. Sl-oiiz. 82.:

Clark, 5. W. 1931. The itoin troll o-ili iii ire a ints- iiri "the llioiiiiiiie: r lRi o
C rande Valleys Tera. Aigir. iii-opt. Star- . 1Z2 1p»

ClEmEJTIQF, D. l., airmd R- iE. Serilflling. 1131115; l-ll-llilfl‘ iii irrli JJJZJHUJ irtie~~till ii are‘
ant: dimensions of the uzrllixiani [Iilltillfllllliirlllllfllitliiil lljltilllillliillilhl iliiiiiieiall ll.
68:1133-1138.

Coon, D. W. , a ncl R. IR. Fl eet. 1l 91710:. The iairit: ii~ii-uaiiri. Finiiiiii‘irioirii
rnent 12:28-38.

C u p p, E. W., a no l . O"l‘-ieail . 1973.. T hie mito»irjplli-ioqg;ienietliiiiiti 
fe-ct of two juven il e h-ormoinie airiallioqggiiii iriirii l|liai|r"'iii~:aie itiiill
imported fire ants. E nwri ir-o ril . llzlillllliifllilillfilliitflllilll 1.1::111E111-~v1l'Pl5ll4ll-...

C reighto ni , W. S. 1930 . T hi e n "liiiioiitllitlll ‘filllfllllhftllifjfilllififilfii oitf‘ ililliii
gen iu s Solenopsis. Proc. imieir  iitiaiiizll? .Alii.i|rlt:sr iilllllilllllialll iiiirgtiil 
66:39-15'l.

C rei ghto n, W. S. 1 ‘9311. Thie a nits iotlli llliillilfillillllilllllllllll iii.tlriieiir'iiiriiai. lllllillillllilllllllll
Mus. Comp. Eool. 131114: 1l-50t5...

Ette rshani ., C. 1966. A gHlTlEiFliZi ire-iiriisii-riirii tori lite tiiiri»irilllitll llllllillllillliillllfl“:
m i ci nae re I ate-d to Soilletnoiyoisiis: aiirliitill iliiilli1aiiriilliiiii-.illiiii<;,igi»e*;itiriiiliiill
Auist. l. Zool. 14:73-171.

22

 

Ferguson, D. E. 1970. Fire ant: whose pests? Science
169:630.

Gibson, J. R., G. W. lvie, and H. W. Dorough. 1972. Fate
of mirex and its major photodecomposition products
in rats. J. Agr. Food Chem. 20:1246-1248.

Glancey, B. M., C. H. Craig, C. E. Stringer, and P. M.
Bishop. 1973. Multiple fertile queens in colonies of the
imported fire ant, So/enopsis invicta. J. Ga. Entomol.
Soc. 8:237-238.

Gregg, R. E. 1963. The ants of Colorado. Univ. Colo. Press.
Boulder, Colo. 792 p.

Green, H. B. 1967. The imported fire ant in Mississippi.
Miss. State Univ. Exp. Sta. B-737. 23 p.

Griffiths, D. 1942. Ants as probable agents in the spread of
Shigel/a infections. Science 96:271-272.

Hays, S. B., and F. S. Arant. 1960. Insecticidal baits for
control of the imported fire ant, So/enopsis saevissima
richteri Forel. J. Econ. Entomol. 53:188-191.

Hays, 5. B., and K. L. Hays. 1959. Food habits of Solenop-
sis saevissima richteri Forel. J. Econ. Entomol. 52:455-
457.

iriess, C. G. 1958. The ants of Dallas County, Texas, and
their nesting sites; with particular reference to soil tex-
ture as an ecological factor. Field and Lab. 26:1-72.

Hung, A. C. F. 1974. Ants recovered from refuse pile of
the pyramid ant, Conomyrma insana (Buckley). Ann.
Entomol. Soc. Amer. 67:522-523.

Hung, A. C. F., 5. B. Vinson, and J. W. Summerlin. 1974.
Male sterility in the red imported fire ant, So/enopsis
invicta. Ann. Entomol. 50c. Amer. 67:909-912.

lvie, F. W., H. W. Dorough, and H. E. Bryant. 1974. Fate of
mirex C” in Japanese quail. Bull. Environ. Cont. Toxi-
col. 11:129-135.

ltuty, F. W., A. R. Yobs, W. G. Johnson, and G. B.
t-tiiiersma. 1974. Mirex residues in human adipose tis-
siue. Environ. Entomol. 3:882-884.

lL.aiii-i-'r=ent.cret, R. 5., J. E. Keil, L. L. Brown, and H. B. Jackson.
1973. The imported fire ant: a newly recognized public
health problem in South Carolina. J. 5.C. Med. Assoc.
69;: 319-321 ..

 R., ‘ti’. J. Chiu, and W. A. Banks. 1973. Laboratory
eivwailuation of candidate bait toxicants against the im-
_p-o~rte-cl fire ant, Solenopsis invicta. Fla. Entomol.
5»6~::14-1-14~6.

lLoi-clk-e="qi~i,. JR- F. 1974;. Systematic reactions to stinging ants. J.
iAiillleirgy Clin. lmmunol. 54:132-146.

llt.»o"ffg;ir»e~rrii,. C. 15., W. A. Banks, and B. M. Glancey. 1975.
lBioll-ogy and c-ontrol of imported fire ants. Ann. Rev.
IE iri t o irri o lll . .20 :: 1 - 30.

llhiifilflfllgififllflll, C. 5., F. J. Bartlett, C. E. Stringer, Jr., and W. A.
lBl.airlilr.s..1'9~6-4r. Imported fire ant toxic bait studies: further
tiesits. liilltr"llllll"ll grariiulated mirex-soybean bait. J. Econ.
IE1 ritoirri oil. 57: 6‘9.5-6~98 .

lll.r:itig;ir'-e~ini_. C.  C. E. Stringer, W. A. Banks, and P. M.
l8ii‘:ii:ll"iioiip». 19617. Laboratory tests with candidate bait toxi-
itiwaiiriiits agiaiirlst lthe imported fire ant. USDA-ARS 81-14. 25
Jill‘:

lllaiifllfilllllgflliiliillilillll_,   C. E. Stringer, and F. J. Bartlett. 1962. Im-
iltii-iriirltl-tiltill fire airit toxic bait studies: GC-1283, a promising
"111111111rtiiaiiinirtp. J Econ. Entomol. 55:405-407.

Long, W. H., E. A. Cancienne, E. J. Cancienne, R. N. Dop-
son, and L. D. Newsom.1958. Fire-ant eradication pro-
gram increases damage by the sugarcane borer. Sugar
Bull. 37:62-63.

Markin, G. P., H. L. Collins, and J. H. Dillier. 1972. Colony
founding by queens of the red imported fire ant, 5o-
lenopsis invicta. Ann. Entomol. Soc. Amer. 65:1053-
1058.

Markin, G. P., J. H. Dillier, S. O. Hill, M. S. B-lum, and
H. R. Hermann. 1971. Nuptial flight and flight ranges
for the imported fire ant, So/enopsis saevissima
richteri. J. Ga. Entomol. Soc. 6:145-156.

Naqvi, S. M., and A. A. de la Cruz. 1973. Mirex incorpora-
tion in the environment: residues in nontarget or-
ganisms - 1972. Pestic. Monit. J. 7:104-111.

O’Neal, J. 1974. Predatory behavior exhibited by three
species of ants on the imported fire ants, So/enopsis
invicta Buren and S. richteri Forel. Ann. Entomol. Soc.
Amer. 67:140.

Reagan, T. E., G. Coburn, and S. D. Hensley. 1972. Effects
of mirex on the arthropod fauna of a Louisiana sugar-
cane field. Environ. Entomol. 1:588:591.

Rhoades, R. B., W. L. Schafer, W. H. Schmid, P. F. Wub-
bena, R. M. Dozier, A. W. Townes, and H. J. Wittig.
1975. Hypersensitivity to the imported fire ant. J. Al-
lergy Clin. lmmunol. 56:84-93.

Sikorovvski, P. P., B. R. Norment, and J. R. Broome. 1973.
Fungi pathogenic to imported fire ants. Miss. Agr.
Forest. Exp. Sta. Inf. Sheet 1212.

Silveiro-Guido, A., J. Carbonell, and C. Crisci. 1973. Ani-
mals associated with the Solenopsis (fire ants) com-
plex, with special reference to Labauchena daguerri.
Proc. Tall Timbers Conf. Ecol. Animal Control Habitat
Manage. 4:41-52.

Smith, M. R. 1936. A list of the ants of Texas. J. Mfr.
Entomol. Soc. 44:155-170.

Smith, M. R. 1965. House-infesting ants of the eastern
United States. USDA-ARS Tech. Bull. 1326. 105 p.
Snelling, R. R. 1963. The United States species of fire ants
of the genus Solenopsis, subgenus So/enopsis
Westwood, with synonymy of So/enopsis aurea
Wheeler. Occasional Papers - No. 3, Bur. Entomol.,

Calif. Dept. Agr. 1-11.

Stringer, C. E., C. S. Lofgren, and F. J. Bartlett. 1964. lrrl-
ported fire ant toxic bait studies: evaluation of toxi-
cants. J. Econ. Entomol. 57:941-945.

Summerlin, J. W. 1976. Polygyny in a colony of the south-
ern fire ant. Ann. Entomol. Soc. Amer. 69:54.

Summerlin, J. W., A. C. F. Hung, and S. B. Vinson. 1977.
Residues in nontarget ants, species simplification; and
recovery of populations following aerial applications of
mirex. Environ. Entomol. 6z193-197.

Travis, B. V. 1941. Notes on the biology of the fire ant,
Solenopsis geminata (F.) in Florida and Georgia. Fla.
Entomol. 24:15-22.

Triosi, S. J., and L. M. Riddiford. 1974. Juvenile hormone
effects on metamorphosis and reproduction of the fire
ant, Solenopsis invicta. Environ. Entomol. 34112-116.

Triplett, R. F. 1973. Sensitivity to the imported fire ant:
successful treatment with immunotherapyl. South.
Med. J. 66:477-480.

Vinson, S. B., and R. Robeau. 1974. Insect growth regu-
lator effects on colonies of imported fire ant. J. Econ.
Entomol. 67:584-587.

Vinson, S. B., R. Robeau, and L. Dzuik. 1974. Bioassay and
activity of several insect growth regulators on the im-
ported fire ant. J. Econ. Entomol. 67:325-328.

Warren. L. 0., and E. P. Rouse. 1969. The ants of Arkan-
sas. Univ. Ark. Agr. Exp. Sta. Bull. 742. 68 p.

Whitcornb, W. H., A. Bhatkar, and J. C. Nickerson. 1973.
Predators of Solenopsis invicta queens prior to coloiny:
establishment. Environ. Entomol. 2:1'l01-'l103.

Williams, R. M, J. R. Panaia, D. Gallo, and W. H. Whit-
comb. 1973. Fire ants attacked by phorid flies. Fla.

. Entomol. 56:159-262.

Wilson, E. O. 1951. Variation and adaptation in the im-
ported fir-e ant. Evolution 5:68-79.

Wilson, E. O. 1952. The Solenopsis saevissirna complex in
South America. Mem. Inst. Oswaldo Cruz. 50:60-68.

Wilson, E. O. 1953. Origin of the variation in the imported
fire ant. Evolution 7:272-263.

Wilson, E. O. 1958. The fire ant. Sci. Amer. March: 36-41.

Wilson, E. O., and W. L. Brown. 1958. Recent changes in
the introduced population of the fire ant Sol-eno-Wpsis
saevissima (Fr. Srnith). Evolution 12:211-218.

Wilson, E. O., and J. H. Eads. 1949. A report on the im-
ported fire ant, Soienopsis saevissima var. ricltteri, in
Alabama. Sypec. Rep. Ala. Dept. Conserv. lvlimeo. 54 p.

Wilson, M. L., and A. D. Oliver. 1969. Food habits of the
imported ant in pasture and pine forest areas in south-
eastern Louisiana. J. Econ. Entomol. 16211268-1271.

Woicilt, D. P., W. A. Ranks, J. ls. Plumley, and C. S. Lof-
gren. 1973. Red‘ imported fire ant: laboratory tests with
additional candidlate bait toxicants. J. Econ. Entomol..
66:550-551.

Wolfe, J. L., and B. R. tilorrnent. 1973. Accumulation of
rnirex residues in selected organisms after an aerial
treatment, Mississippi, 1971-72. iPestic. Monit. J].
7::1'l2—1l6.

23

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