Hubbry Logo
Fire antFire antMain
Open search
Fire ant
Community hub
Fire ant
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Fire ant
Fire ant
Fire ant
View on Wikipedia
from Wikipedia

Fire ant
Temporal range: Early Oligocene–Recent
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Solenopsidini
Genus: Solenopsis
Westwood, 1840
Type species
Solenopsis geminata
Fabricius, 1804
Diversity[1]
201 species

Fire ants are several species of ants in the genus Solenopsis, which includes over 200 species. Solenopsis are stinging ants, and most of their common names reflect this, for example, ginger ants and tropical fire ants. Many of the names shared by this genus are often used interchangeably to refer to other species of ant, such as the term red ant, mostly because of their similar coloration despite not being in the genus Solenopsis. Both Myrmica rubra and Pogonomyrmex barbatus are common examples of non-Solenopsis ants being termed red ants.[2]

None of these common names apply to all species of Solenopsis nor exclusively to species of Solenopsis; for example, several species of weaver ants of the genus Oecophylla in Southeast Asia are colloquially called "fire ants" because of their similar coloration and painful bites, but the two genera are not closely related. Wasmannia auropunctata is another unrelated ant more commonly called the "little fire ant" due to its potent sting.[3]

Appearance

[edit]
Fire ant mound
Fire ant mound
Detail of fire ant head
Detail of the head (Solenopsis geminata)

The bodies of mature fire ants, like the bodies of all typical mature insects, are divided into three sections: the head, the thorax, and the abdomen, with three pairs of legs and a pair of antennae. Fire ants of those species invasive in the United States can be distinguished from other ants locally present by their copper brown head and thorax with a darker abdomen. The worker ants are blackish to reddish and their size varies from 2 to 6 mm (0.079 to 0.236 in). In an established nest these different sizes of ants are all present at the same time.[4]

Solenopsis spp. ants can be identified by three body features—a pedicel with two nodes, an unarmed propodeum, and antennae with 10 segments plus a two-segmented club.[5] Many ants bite, and formicine ants can cause irritation by spraying formic acid; myrmecine ants like fire ants have a dedicated venom-injecting sting, which injects an alkaloid venom, as well as mandibles for biting.[6]

Behavior

[edit]
Fire ant worker, queen, and male
A fire ant worker (bottom), queen (top), and male (right)

A typical fire ant colony produces large mounds in open areas, and feeds mostly on young plants, insects and seeds. Fire ants often attack small animals such as small lizards and can kill them. Unlike many other ants, which bite and then spray acid on the wound, fire ants bite only to get a grip and then sting (from the abdomen) and inject a toxic alkaloid venom called solenopsin, a compound from the class of piperidines. For humans, this is a painful sting, a sensation similar to what one feels when burned by fire (hence the name), and the after-effects of the sting can be deadly to sensitive people.[7] Fire ants are more aggressive than most native species, so have pushed many species away from their local habitat. One such species that Solenopsis ants parasitically take advantage of are bees, such as Euglossa imperialis, a nonsocial orchid bee species, from which the ants enter the cells from below the nest and rob the cell's contents.[8]

These ants are renowned for their ability to survive extreme conditions. They do not hibernate, but can survive cold conditions, although this is costly to fire ant populations as observed during several winters in Tennessee, where 80 to 90% of colonies died due to several consecutive days of extremely low temperatures.[9]

Fire ants have been known to form mutualistic relationships with several species of Lycaenidae and Riodinidae butterflies.[10][11] In Lycaena rubidus, the larvae secrete a fluid that is high in sugar content. Fire ants bring the larvae back to the nest, and protect them through the pupal stage in exchange for feeding on the fluid.[11] In Eurybia elvina, fire ants were observed to frequently construct soil shelters over later instars of larvae on inflorescences on which the larvae are found.[10]

Fire ants nest in the soil, often near moist areas, such as river banks, pond shores, watered lawns, and highway shoulders. Usually, the nest will not be visible, as it will be built under objects such as timber, logs, rocks, or bricks. If no cover for nesting is available, dome-shaped mounds are constructed, but these are usually only found in open spaces, such as fields, parks, and lawns. These mounds can reach heights of 40 cm (16 in),[4] but can be even higher on heavier soils, standing at 1.0 m (3 ft 3 in) in height and 1.5 m (4 ft 11 in) in diameter.[12] Colonies are founded by small groups of queens or single queens. Even if only one queen survives, within a month or so, the colony can expand to thousands of individuals. Some colonies may be polygynous (having multiple queens per nest).[13]

Fire ants are resilient and can survive floods. During Hurricane Harvey in Texas in 2017, clumps of fire ants, known as rafts, were seen clumped together on the surface of the water. Each clump had as many as 100,000 individual ants, which formed a temporary structure until finding a new permanent home.[14] Ants clumped in this way will recognize different fluid flow conditions and adapt their behavior accordingly to preserve the raft's stability.[15]

Fire ants dig tunnels efficiently using about 30% of the population of the colony, thereby avoiding congestion in tunnels.[16]

Queens, males and workers

[edit]
Solenopsis winged reproductive females, queens and workers
Solenopsis winged reproductive females, queens and workers

Queen

[edit]

Fire ant queens, the reproductive females in their colony, also are generally the largest. Their primary function is reproduction. Typically, a fire ant queen will seek to establish a new colony following a nuptial flight, wherein it will use its special venom to paralyze offending competitors,[17] in the absence of workers for defense. Fire ant queens may live up to seven years and can produce up to 1,600 eggs per day, and colonies will have as many as 250,000 workers.[12][18] The estimated potential life span is around 5 years and 10 months to 6 years and 9 months.[19] Young, virgin fire ant queens have wings (as do male fire ants), but they often cut them off after mating. Occasionally, a queen will keep its wings after mating and through its first year.

Males (drones)

[edit]

Male fire ants mate with queens during a nuptial flight. After a male has successfully inseminated a queen, the male will not get accepted back to the mother colony, and will eventually die outside the nest.[20]

Workers

[edit]

The other roles in an ant colony are usually undertaken by workers. Fire ant workers are haphazardly divided into different size classes, namely minima, minor, media, and major workers.[21] The major ants are known for their larger size and more powerful mandibles typically used in macerating and storing food items (i.e. as repletes), while smaller workers take care of regular tasks (the main tasks in a colony are caring for the eggs/larvae/pupae, cleaning the nest, and foraging for food).[12] However, Solenopsis daguerrei colonies contain no workers, as they are considered social parasites.[22]

Invasive species

[edit]
Further information on invasive species: Red imported fire ant
Fire Ant Festival Sign
Sign for the Fire Ant Festival in Ashburn, Georgia

Although most fire ant species do not bother people and are not invasive, Solenopsis invicta, known in the United States as the red imported fire ant (or RIFA), is an invasive pest in many areas of the world, including the United States, Australia, China and Taiwan.[23] The RIFA was believed to have been accidentally introduced to these countries via shipping crates, particularly in the case of Australia.[24]

In Australia, RIFA ants were first identified in the Port of Brisbane in 2001, although a strategic review of the Australian RIFA eradication program published in 2021 suggested that RIFA ants may have been present but undetected in Australia as early as 1992.[24][25][26] As of November 2023, the invasion of fire ants is restricted to an area of 7000 km2 in South East Queensland that includes Brisbane, with the colonised area bordering the state of New South Wales (NSW), with incursions reported in northern NSW on a regular basis.[27][25] Outside of this region, as of 2023, there have been seven other incursions that have had to be eradicated, with all incursions linked to ports and airports, including in Gladstone, the Port of Botany near Sydney (in 2014), and the Port of Fremantle, Western Australia.[25][28] Elsewhere, fire ants have been frequently intercepted on incoming cargo in ports and airports across Australia.[29] Of particular concern, Australian researchers predict that the entire country is able to provide suitable habitat for RIFA colonization, with the exception of highland Tasmania and the Snowy Mountains.[26] In the 21-year time period between 2001 and 2022, the commonwealth and state governments of Australia spent a combined AU$644m in their attempts to eradicate RIFA ants. In 2015, the Australian National Red Imported Fire Ant Eradication Program (NRIFAEP) National Fire Ant Eradication Program was set up and received AU$411m of funding. For the time period of 2023-2027, funding of AU$593m has been agreed. Despite the funded plan and a degree of success in the eradication of RIFA not seen elsewhere in the world, some Australian experts warn that the government on a national and state level may be moving too slowly given the size of the threat.[25]

They were believed to be in the Philippines, but they are most likely to be misidentified for Solenopsis geminata ants.[30]

In the US, the FDA estimates that more than $5 billion is spent annually on medical treatment, damage, and control in RIFA-infested areas. Furthermore, the ants cause approximately $750 million in damage annually to agricultural assets, including veterinarian bills and livestock loss, as well as crop loss.[31] Over 40 million people live in RIFA-infested areas in the southeastern United States.[32] It is estimated that 30–60% of the people living in fire ant-infested areas of the US are stung each year.[33] RIFA are currently found mainly in warmer US states in the south-east of the country including Florida, Georgia, South Carolina, Louisiana, Mississippi and Alabama, but extend to include parts of North Carolina, Virginia, Tennessee, Arkansas, Texas, Oklahoma, New Mexico, and California.[34]

Since September 2004, Taiwan has been seriously affected by the red fire ant. The US, Taiwan and Australia all have ongoing national programs to control or eradicate the species, but with the exception of those in Australia, none have been especially effective. According to a study published in 2009, it took only seventy years for the lizards in parts of the United States to adapt to the ant's presence; they now have longer legs and new behaviors that aid them in escaping from the danger.[35]

Solenopsis invicta is the most famous species in this genus, especially in the US, however several other species are similarly dangerous and invasive, such as Solenopsis geminata, which has invaded most of the tropical countries, wreaking havoc in medical systems, especially in unprepared countries and islands.[36]

Sting effects

[edit]
Human leg three days after brief contact with fire ant colony
A human leg three days after brief contact with a fire ant colony

The venom of fire ants is mainly (>95%) composed of oily alkaloids structurally derived from piperidine (also known as solenopsins) mixed with a small amount of toxic proteins.[37][38] Fire ant stings are painful, characterised by a local burning sensation, followed by urticaria.[37] The sting site typically swells into a bump within hours, which can cause further pain and irritation, especially following several stings at the same place. The bump may develop into a white pustule within 24–36 hours which can become infected if scratched, but will spontaneously flatten within a few days if left alone. The pustules are obtrusive and uncomfortable while active and, if they become infected, may cause scarring.[39] Some people may become allergic to the venom,[40] and if untreated, may become increasingly sensitive to the point of experiencing anaphylaxis following fire ant stings, which requires emergency treatment.[36] Management of an emergency visit due to anaphylaxis is recommended with the use of adrenaline.[41][36] It has been demonstrated that, whilst pustule formation results from the injected venom alkaloids,[42] allergy to fire ant stings is caused solely by venom allergenic proteins.[40]

Treatment

[edit]

First aid for fire ant stings includes external treatments and oral medicines. There are also many home remedies of varying efficacy, including immediate application of a solution of half bleach and half water, or aloe vera gel – the latter of which is also often included in over-the-counter creams that also include medically tested and verified treatments.[7] External, topical treatments include the anesthetic benzocaine, the antihistamine diphenhydramine, and the corticosteroid hydrocortisone.[7] Antihistamines or topical corticosteroids may help reduce the itching and will generally benefit local sting reactions.[43] Oral medicine includes antihistamines.[44] Severe allergic reactions to fire ant stings, including severe chest pain, nausea, severe sweating, loss of breath, serious swelling, and slurred speech[45] can be fatal if not treated.[46][36]

Predators

[edit]
Venus flytrap
Drosera with sticky leaves
A species of Drosera with its sticky leaves that trap many ants
Phorid fly parasitoid of fire ants
Pseudacteon curvatus, phorid fly parasitoid of fire ants

Phorid flies, or Phoridae, are a large family of small, hump-backed flies somewhat smaller than vinegar flies; two species in this family (Pseudacteon tricuspis and Pseudacteon curvatus) are parasitoids of the red imported fire ant in its native range in South America. Some 110 species of the genus Pseudacteon, or ant-decapitating flies, have been described. Members of Pseudacteon reproduce by laying eggs in the thorax of the ant. The first instar larvae migrates to the head, then develops by feeding on the hemolymph, muscle tissue, and nervous tissue. After about two weeks, they cause the ant's head to fall off by releasing an enzyme that dissolves the membrane attaching the ant's head to its body. The fly pupates in the detached head capsule, emerging two weeks later.[47]

Pseudacteon flies appear to be important ecological constraints on Solenopsis species and they have been introduced throughout the southern United States, starting with Travis, Brazos, and Dallas counties in Texas, as well as south central Alabama, where the ants first entered North America.[48]

The Venus flytrap, a carnivorous plant, is native only to North and South Carolina in the United States. About 33% of the prey of the Venus flytrap are ants of various species.[49] They lure their prey with a sweet sap. Once the prey has entered the trap and within about three seconds of touching two or three "trigger hairs" on the surface of the trap, the leaf closes around the prey and digests it. The majority of ants that are captured include non-native RIFAs, and three other species of ants.[49] Other carnivorous plants, such as sundews (Drosera) and various kinds of pitcher plants also trap many ants.

Key natural enemies of fire ants also include other ant species which will attack prospective queens during the nest founding period, when there is an absence of workers to defend the emergent colony.[50] Frequent competitors of fire ant founding queens include other Solenopsis thief ant species, and some invasive pest species, such as the tawny crazy ant, and the black crazy ant.[17]

A number of entomopathogenic fungi are also natural enemies of fire ants, such as Beauveria bassiana[51] and Metarhizium anisopliae[52]. The latter is commercially available for the biological control (as an alternative to conventional pesticides) of various pest insects, and a new proposed technology has increased its shelf life and efficiency against fire ants.[53]

Species

[edit]
Main article: List of Solenopsis species

The genus Solenopsis contains over 200 species.[1] Not all species included in the genus are known as fire ants, but most are small slow-moving ants which are unable to sting, called thief ants. "True" fire ants are but a group of about 20 species of Solenopsis which are larger, and will viciously sting in swarms whenever disturbed.[54] Some of the most studied species include:

See also

[edit]

References

[edit]

Further reading

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Fire ant

View on Grokipedia
from Grokipedia
Fire ants are ants of the genus Solenopsis in the subfamily Myrmicinae, notable for their potent venomous stings that deliver alkaloids causing intense burning pain and localized tissue damage, with the (Solenopsis invicta) representing the most widespread and impactful species. Native to subtropical regions of , these polymorphic insects form large colonies featuring wingless workers varying from 1.5 to 5 mm in length, with dark reddish-brown heads and thoraces contrasted by black abdomens. Introduced accidentally to the in via shipping ports, S. invicta has proliferated across approximately 350 million acres, displacing native ant through aggressive , superior , and stinging defenses that deter competitors. Colonies, often exceeding 250,000 individuals, construct conspicuous earthen mounds up to 40 cm high and aggressively defend territories, contributing to annual economic losses estimated at $8 billion from crop damage, livestock injuries, and infrastructure disruptions in infested areas. The stings of fire ants trigger immediate wheal-and-flare reactions in nearly all victims, evolving into sterile pustules within hours due to venom-induced , with multiple stings risking severe allergic responses or in sensitized individuals, though fatalities remain rare outside cases. Ecologically, their disrupts by preying on ground-nesting birds, reptiles, and while outcompeting native for resources, though some studies note context-dependent effects where fire ants may control pest populations in agricultural settings. Management relies on chemical baits, biological controls like phorid fly parasitoids, and measures, underscoring their status as a model for studying dynamics.

Taxonomy and Classification

Scientific Classification

Fire ants comprise several species within the genus Solenopsis, subfamily Myrmicinae, family Formicidae, distinguished by their polymorphic workers, aggressive defense, and potent venomous sting causing a burning sensation. The term primarily applies to members of the S. saevissima species group, including the (S. invicta Buren, 1972) and black imported fire ant (S. richteri Forel, 1903), both originating from . The taxonomic hierarchy for Solenopsis invicta, the most widely studied and invasive fire ant species, is:
RankClassification
KingdomAnimalia
PhylumArthropoda
ClassInsecta
OrderHymenoptera
FamilyFormicidae
SubfamilyMyrmicinae
GenusSolenopsis
SpeciesS. invicta
This classification reflects the ants' placement among eusocial Hymenoptera, with Formicidae encompassing approximately 12,000 described ant species worldwide. S. invicta was initially classified as a variant of S. saevissima by Santschi in 1916 but elevated to full species status by Buren in 1972 based on morphological and behavioral distinctions from S. richteri. The genus Solenopsis includes over 200 species, divided into "fire ant" types (larger, stinging) and thief ants (smaller, non-stinging), with fire ants characterized by a functional sting apparatus and alkaloid venom.

Etymology and Common Names

The "fire ant" applies to several in the genus Solenopsis (subfamily Myrmicinae), particularly those notorious for their aggressive defense and stings that deliver causing an intense burning sensation akin to fire. This nomenclature reflects the physiological effect of their alkaloid-based , primarily solenopsins, which induce pustules and pain lasting hours to days in humans. The genus name Solenopsis, established by John Obadiah Westwood in 1840, derives from solēn ("pipe," "channel," or "tube") combined with opsis ("appearance" or "sight"), describing the slender, tubular petiole that connects the ant's to its gaster, giving the a channeled profile. Species epithets further denote traits; for instance, Solenopsis invicta ("unconquered" in Latin) highlights the species' invasive resilience and competitive dominance. Among common names, "" designates S. invicta, introduced to the from in the 1930s via , while "black imported fire ant" refers to S. richteri, a related invasive from similar origins. Native North American species include the "" (S. xyloni) and "tropical fire ant" (S. geminata), both stinging members of the genus but less aggressively invasive than imported forms. Smaller, non-stinging Solenopsis species are often termed "thief ants" to distinguish them from true fire ants.

Morphology

External Features

Fire ants of the Solenopsis, particularly S. invicta, exhibit the typical hymenopteran divided into three tagmata: head, mesosoma (), and gaster (), connected by a two-segmented petiole consisting of a node and postnode. The is chitinous and sclerotized, providing and protection, with the surface often punctate and somewhat shiny. Workers are polymorphic, ranging in size from 1.5 to 6 mm in length, with minor workers smaller and majors larger, showing allometric changes where larger individuals have proportionally larger gasters, more heart-shaped heads, and elongate mesosomas. Coloration is characteristically reddish-brown on the head and mesosoma, transitioning to a darker, often blackish gaster. The head features large compound eyes and geniculate antennae with 12 segments, the apical two forming a distinct club; mandibles are triangular with three prominent teeth. The mesosoma bears three pairs of legs and, in alates, wings, while the gaster terminates in a stinging apparatus visible as an acidopore, enabling injection. Reproductives ( and males) are larger, with up to 12 mm and males smaller, both possessing ocelli and functional wings prior to flights.

Caste Variations


Fire ant colonies, primarily of Solenopsis invicta, feature three castes: workers, queens, and , differentiated by morphology, reproductive capacity, and function. Workers are sterile, wingless females exhibiting polymorphism with continuous size variation rather than discrete subcastes. Body lengths range from 1.5 to 5 mm, with head widths spanning 0.5 to 1.5 mm. As worker size increases, head width grows disproportionately relative to body length, resulting in larger individuals possessing broader heads and more robust mandibles adapted for tasks like nest defense and processing tougher food sources. Smaller workers, conversely, specialize in brood care and foraging for smaller items. Queens represent the reproductive and are the largest individuals, typically exceeding worker sizes with body lengths up to 6 mm or more, featuring a developed for initial winged dispersal and enlarged ovaries for egg production. queens possess wings that are shed post-mating upon colony founding, transitioning to a dealate form focused on sustained , potentially laying thousands of eggs daily in mature colonies. Males, or drones, are winged and smaller than queens, characterized by black coloration, reduced head size, diminutive mandibles lacking the worker's cutting efficiency, and absence of a stinger. Their morphology prioritizes flight and mating, with spermatozoa measuring approximately 70 μm in length; males perish after nuptial flights upon sperm transfer. This caste dimorphism underscores the species' reproductive strategy, where males contribute genetically but do not participate in colony maintenance.

Reproduction and Colony Dynamics

Mating and Queen Establishment

Mating in the , Solenopsis invicta, takes place during nuptial flights triggered by heavy rainfall after a dry period in warm weather, typically from spring through late fall. Winged males emerge first from mature colonies, followed by virgin queens, who ascend and mate once in mid-air, often at heights of hundreds of feet. Males perish shortly after insemination, while queens, carrying stored sperm sufficient for lifelong fertilization, disperse via wind, potentially traveling up to 12 miles, though most settle within a mile of the parent colony. Following dispersal, inseminated queens shed their wings (dealate) and excavate a small chamber a few inches deep in moist soil, sealing it to begin claustral colony founding without external foraging. Nourished solely by body reserves and degenerating wing muscles, the queen lays an initial clutch of 10 to 20 eggs, which she incubates and tends through larval and pupal stages. The first worker ants emerge after about 25 to 35 days, foraging to support further colony growth, at which point the queen resumes egg-laying at rates up to 5,000 per day in mature colonies. Founding success is low, with predation—often by conspecific workers from nearby —desiccation, or nutritional shortfall causing most to fail, though successful can expand to over 100,000 individuals within 6 to 9 months. In monogyne populations, featuring a single per , founding is typically independent (haplometrotic). Polygyne populations, with multiple per , exhibit alternative strategies: may infiltrate and be adopted into existing nests or initiate pleometrotic founding, where groups of 5 to 20 cooperate to rear initial workers before lethal intraspecific combat reduces numbers to one or a few survivors. This pleometrosis enhances early survival against predators but leads to kin via fighting.

Colony Growth and Polygyne vs Monogyne Forms

Fire ant colonies begin development after a mated queen excavates a small chamber in the and lays her first clutch of 10 to 20 eggs, which hatch into larvae within 7 to 10 days; the queen provides nourishment from her own metabolic reserves until the first nanitic workers emerge after approximately 25 to 35 days. These initial workers, smaller and more numerous than later castes, expand the nest, for , and tend subsequent brood, enabling the colony to transition from the founding phase—dependent solely on the queen's resources—to the growth phase, where worker populations increase exponentially through continuous brood production. maturation, marked by the production of winged reproductives (alates), typically occurs 6 to 12 months after founding, depending on environmental conditions like and resource availability, with full reproductive capacity reached in 1 to 2 years for viable colonies. Average mature colonies house 100,000 to 250,000 workers, though sizes vary with social form and habitat. The , Solenopsis invicta, manifests two distinct social forms—monogyne (single queen) and polygyne (multiple )—which profoundly influence growth dynamics, expansion, and persistence. Monogyne colonies, founded claustrally by a solitary mated queen dispersing via , prioritize individual queen productivity, with oviposition rates supporting rapid worker accumulation to 100,000 or more before alate production; these colonies exhibit discrete boundaries, higher worker aggression, and dispersal primarily through independent alate swarming. In contrast, polygyne colonies incorporate multiple queens (often 10 to hundreds) through adoption or pleometrotic founding, resulting in reduced per-queen —requiring at least nine polygyne queens to match the reproductive output of one monogyne —but collective brood production that sustains larger, interconnected networks. Polygyne growth diverges markedly via colony , where reproductives and workers migrate short distances to establish satellite nests without flight, fostering expansive supercolonies with densities up to six times higher than monogyne populations (e.g., 200–800 per versus 20–150). This budding strategy enhances resilience, as polygyne forms demonstrate slower demise from pathogens and greater tolerance to control measures compared to monogyne colonies, which rely on isolated, more vulnerable single-queen units. Transitions between forms occur in sympatric populations, with polygyne prevalence often linked to reduced dispersal and higher local densities, amplifying invasive potential in disturbed habitats.

Behavior

Foraging and Diet

Fire ants, particularly Solenopsis invicta, exhibit an omnivorous diet comprising carbohydrates such as honeydew, plant exudates, sugars, and syrups; proteins from live and dead , other arthropods, and meats; and from sources like eggs and seeds. This dietary breadth enables opportunistic feeding, with colonies preying on small during daytime peaks and scavenging carrion or crop residues as available. Studies of confirm that arthropods dominate the solid diet (up to 59% overlap in identifiable items between species), supplemented by seeds and nectar, reflecting adaptation to varied habitats. Foraging behavior follows a structured sequence of searching, pheromone-based recruitment, and transportation, with workers more efficient on hard, smooth surfaces like plastic than on soil, where traction limits speed. Small food items are often retrieved individually without aid, but larger or abundant resources trigger mass recruitment via chemical trails, enhancing colony intake rates. Colony-level diet regulation occurs through feedback mechanisms: forager activity aligns with brood and queen nutritional demands, prioritizing carbohydrates for energy and proteins for growth, with preferences shifting based on internal depletion. Liquid baits reveal variable preferences, such as higher recruitment to sugars over oils or sera in some assays, though overall omnivory ensures flexibility. Workers occasionally bury excess food near the nest, potentially reducing immediate pressure and preserving resources against competitors or environmental loss, though this correlates with temporary activity suppression. infections, like Solenopsis invicta virus-3, can disrupt this by decreasing foraging rates and altering macronutrient selectivity, underscoring behavioral plasticity in response to stressors.

Aggression and Defense Mechanisms

Fire ants, particularly Solenopsis invicta, display pronounced aggression in defense of their colonies, swarming intruders en masse upon disturbance of the nest. Workers grasp threats with their mandibles before stinging repeatedly, often pivoting their bodies to deliver multiple injections in a circular pattern around the bite site, enabling up to seven or eight stings per individual ant without fatal self-injury. This behavior contrasts with that of bees, which typically sting only once due to barbed stingers that lodge in the victim. The apparatus facilitates efficient delivery, with penetrating to inject a potent mixture dominated by alkaloids (over 95% of composition), which induce intense burning pain, pustule formation, and potential or systemic allergic reactions in humans, including from as little as 10–100 ng of protein per sting. also serves roles and aids in prey immobilization, underscoring its multifunctional defensive utility. In addition to chemical weaponry, employ mandibular bites for initial anchoring and of larger adversaries. Alarm communication amplifies collective defense through pheromones released from mandibular glands or during venom spraying, which recruit nearby workers, elicit rapid orientation toward the threat, and intensify attack coordination; these signals can propagate across the , drawing hundreds of defenders within seconds. Defensiveness escalates under environmental stress, such as flooding, where workers exhibit heightened venom discharge and aggression to protect colonies. This multi-layered strategy—combining chemosensory alerting, mass mobilization, and toxic injection—renders fire ant colonies formidable against predators, vertebrates, and mechanical disturbances alike.

Nest Construction and Social Organization

Red imported fire ant (Solenopsis invicta) colonies construct subterranean nests comprising a network of chambers and tunnels excavated by workers from surrounding . The queen initiates founding by digging a small chamber shortly after , sealing herself inside to rear the first brood of 5 to 35 workers using metabolic reserves without external . Upon emergence, these minim workers expand the nest by tunneling through to form interconnected galleries for brood rearing, queen housing, and food storage, piling excavated material above the nest to create a typically 20-40 cm in and up to 40 cm high. s are often dome-shaped in clay s and feature no central visible entrance; instead, radial tunnels extend outward from the base, sometimes meters away, to access resources while minimizing predator detection at the core nest. Workers maintain and repair nest structures, enlarging chambers after rainfall or disturbances to regulate internal and humidity, which can reach optimal levels of 29-32°C for brood development. Fire ant societies are eusocial, organized into three castes: fertile , sterile female workers, and short-lived males, with division of labor ensuring efficiency. , the sole or primary egg-layers depending on social form, focus on after establishment, producing up to 1,600 eggs daily in mature nests. Workers, comprising the vast majority (up to 250,000 in monogyne ), exhibit size polymorphism from minor (2-4 mm) to major (5-6 mm) individuals; smaller workers primarily nurse brood and tend the queen, while larger ones forage, defend the via venomous stings, and excavate nest expansions. Males, winged and produced seasonally, exist only to mate with virgin during nuptial flights before dying. Colonies occur in monogyne (single-mated queen, territorial) or polygyne (multiple , interconnected supercolonies) forms, genetically determined by variants of a social supergene spanning over 500 genes. In monogyne forms, workers recognize and execute supernumerary queens post-worker emergence to enforce single queenship; polygyne forms suppress this execution, allowing recruitment and larger, less aggressive networks spanning hectares with millions of workers. Pheromonal communication coordinates tasks, with trail pheromones guiding foragers and alarm pheromones mobilizing defenses, underpinning the rigid yet adaptive specialization.

Native Ecology

Original Habitat and Distribution

The , Solenopsis invicta, originates from subtropical lowland regions of central , with its native range centered in the wetland system spanning southeastern , , southern (particularly state), and northern . This distribution aligns with the and basins, where populations are documented from areas near Cáceres and Rondonópolis in to the vicinity in and . In its indigenous environment, S. invicta predominantly occupies open grasslands, savannas, and seasonally inundated floodplains, favoring sunny, disturbed sites such as riverbanks, wetlands, and areas prone to natural perturbations like flooding or landslides. Colonies construct earthen mounds in loose, well-drained soils within these habitats, exploiting the periodic flooding for dispersal via on vegetation or debris. The species' prevalence in such dynamic ecosystems reflects adaptations to variable moisture and temperature regimes typical of the Pantanal's wet-dry cycles. Other fire ant species in the Solenopsis, such as the tropical fire ant (S. geminata), share broader native distributions across tropical Central and , but S. invicta represents the primary associated with the "fire ant" descriptor in ecological and invasive contexts due to its aggressive traits and mound-building. Native densities remain lower than in introduced ranges, constrained by specialist predators and competitors absent in non-native areas.

Interactions with Native Biota

In its native range across the floodplains of the Paraná-Paraguay River basins in Argentina, Brazil, Paraguay, and Uruguay, Solenopsis invicta functions as a generalist predator and scavenger, consuming a diverse array of native arthropods including insects, spiders, and small invertebrates, as well as seeds and honeydew from hemipterans. This opportunistic foraging contributes to local arthropod community dynamics, where fire ant colonies exert pressure on smaller or less aggressive native species through direct predation and interference competition at food resources. Studies in northeastern Argentina have documented S. invicta achieving high ecological dominance at bait stations despite slower resource discovery rates compared to co-occurring ants, primarily via aggressive displacement behaviors that limit access for other foraging species. However, such dominance is context-dependent and moderated by habitat variability, with fire ants coexisting alongside larger native ants like Camponotus spp. in less disturbed floodplains. Fire ants also face significant biotic constraints from native predators and parasites, which prevent the unchecked expansions observed in introduced ranges. Colonies are parasitized by up to 20 of phorid flies (Pseudacteon spp.), whose larvae develop inside workers, inducing behavioral changes such as reduced and increased grooming that can decrease colony efficiency by limiting activity outside nests. Additional native antagonists include eucharitid wasps that target brood, microsporidian fungi like Kneallhazia solenopsae, and parasites, all of which collectively maintain lower fire ant densities—typically 4-7 times below those in non-native habitats lacking these regulators. predators such as armadillos, anteaters, and certain birds further prey on workers and brood, integrating fire ants into the broader trophic web without evidence of widespread declines attributable to them. These interactions underscore S. invicta's role as an embedded component of South American ecosystems, where competitive and predatory behaviors are balanced by a suite of coevolved enemies, contrasting sharply with its suppressive effects on biota post-introduction. In undisturbed native habitats like the wetlands, fire ant abundance correlates with flood cycles, during which inundation disrupts colonies and favors recovery of competing arthropods. Empirical surveys indicate no systemic linked to fire ants in their origin areas, with diversity persisting alongside them due to these regulatory mechanisms.

Invasive History

Initial Introductions

The (Solenopsis invicta), native to subtropical regions of including northern , southern , and , was first introduced to the in the late 1930s through accidental transport via soil used as ballast in cargo ships arriving at the , . This species likely originated from areas near the basin, where multiple introductions from a single source population have been genetically traced. The arrival postdated the earlier introduction of the black imported fire ant (S. richteri) around in the same locality, which had established limited populations in adjacent and counties by the 1920s before being largely displaced by the more aggressive S. invicta. Early colonies of S. invicta were not formally identified until the 1940s, with entomologist noting their presence as a child in the Mobile area, leading to scientific confirmation by 1945. The exact year of arrival remains uncertain, with estimates ranging from 1933 to 1945, but port records and genetic evidence support a singular foundational event rather than multiple independent introductions at that site. Unlike the black imported fire ant, which spread slowly and remained confined, S. invicta exhibited rapid colony founding aided by its polygyne social form, enabling quick establishment in disturbed habitats near the port. This initial U.S. served as the primary source for subsequent invasions, with no verified earlier detections elsewhere; efforts were absent until the species' impacts became evident in the . Genetic analyses confirm that North American populations derive almost entirely from this Mobile introduction, underscoring the risks of unregulated maritime trade in soil and plant materials from endemic regions.

Global Spread and Recent Expansions (Post-2020)

The (Solenopsis invicta) has dispersed globally beyond its native range in subtropical , primarily through human-mediated transport such as in , nursery plants, and shipping containers, establishing self-sustaining populations in the since the 1930s, since 2001, since 2002, and since 2004. By 2020, infested areas encompassed approximately 350 million acres in the U.S. alone, with ongoing northward and westward expansions facilitated by suitable climates and lack of natural predators. Post-2020 expansions in the U.S. include rapid range growth in , where surveys from 2021–2022 detected S. invicta in seven counties (Charlotte, Chesterfield, Dinwiddie, Halifax, Lunenburg, Pittsylvania, and ) outside the federal quarantine zone, exceeding model predictions from 2008 and indicating accelerated dispersal likely via vehicle traffic and landscaping materials. In , a national eradication program faced setbacks with a confirmed detection in on January 19, 2024, genetically linked to the southeastern incursion, prompting intensified and treatment across over 1,000 properties. In Asia, China reported multiple new occurrence records in 2021, expanding S. invicta's footprint in southern provinces through ports and agricultural trade, with infestations now threatening over 100,000 hectares of farmland and urban areas. Detections in (Kobe) and (Daegu) emerged in recent years, representing potential bridgehead invasions from established Asian populations, though containment efforts have limited establishment. No confirmed post-2020 establishments occurred in or , despite modeled suitability in Mediterranean and subtropical zones; however, the species' inclusion on the EU's list of invasive alien species of concern in 2022 underscores vigilance against imports. Climate projections suggest further potential northward shifts in invaded regions under warming scenarios, amplifying invasion risks via polygyne colony forms that enhance dispersal.

Impacts

Ecological Disruptions

The , Solenopsis invicta, disrupts native ecosystems primarily through aggressive competition, predation, and habitat alteration, leading to decreased and shifts in community structures. In infested areas, is significantly reduced while overall abundance increases due to high densities of S. invicta, altering communities and diminishing the ecological roles of . This dominance extends to outcompeting for resources and habitats, thereby reducing functional diversity in ecosystems and disrupting mutualistic relationships, such as those between and honeydew-producing , which in turn affects food availability for other . Predation by S. invicta targets ground-dwelling and nesting , including , spiders, , frogs, birds, and small mammals, often resulting in population declines or local extirpations of vulnerable . For instance, fire ants prey on hatchlings and eggs of ground-nesting birds such as , contributing to reduced recruitment rates in affected populations. They also attack small vertebrates like snakes and amphibians, exacerbating in grasslands and forests where native predators are displaced. In agricultural and natural habitats, this predation pressure, combined with competitive exclusion, has been linked to broader trophic cascades, indirectly impacting higher-level consumers reliant on abundant prey. Habitat modifications from fire ant mound construction further compound disruptions by altering , , and retention, which can inhibit seed germination and root growth in native plants while favoring weedy . In southeastern U.S. ecosystems, these changes have been observed to reduce overall ground-layer and interfere with establishment in forests recovering from disturbances. Additionally, S. invicta displaces native that play key roles in and soil turnover, leading to homogenized with diminished resilience to environmental stresses. Such alterations underscore the invasive 's capacity to reshape invaded landscapes, with long-term implications for ecosystem services like nutrient cycling and .

Economic and Agricultural Costs

The (Solenopsis invicta) generates substantial economic costs in through direct damage to crops and , as well as required control measures, contributing to national estimates exceeding $750 million annually in agricultural losses as reported by the U.S. Department of Agriculture in 2003. These impacts form a significant portion of broader economic damages from fire ants, which surpass $6 billion per year across affected sectors including and production. In infested southern states, fire ant mounds disrupt farm machinery and systems, while workers prey on seeds, seedlings, and tender plant tissues, exacerbating yield reductions in vulnerable crops. Crop-specific damages are pronounced in field crops where fire ants target germinating seeds and young plants. Soybean production suffers notable losses, with estimates of up to $156.4 million annually in the southeastern United States due to ant predation and interference. Similar effects diminish yields in corn, sorghum, potatoes, okra, and other vegetables, where ants consume up to 20-30% of emerging seedlings in heavily infested fields, as observed in early infestation reports from the 1940s onward. In regions like southern Arkansas, annual crop losses averaged $4.2 million, predominantly from soybeans at $3.3 million, highlighting spatial variability tied to infestation density. Livestock sectors incur costs from aggressive stinging attacks that injure or kill neonates, such as calves and piglets, and deter near nests, leading to lower weight gains and higher veterinary expenses. In cattle operations, fire ant impacts result in per-farm losses averaging $26 to higher amounts in high-infestation districts, driven by animal health declines and operational disruptions. Nationally, these veterinary and losses compound agricultural burdens, with fire ants affecting over 367 million acres of potential pastureland. Mitigation adds further expenses, with broadcast treatments using insecticidal baits costing $8-10 per pound and requiring 1-1.5 pounds per acre for effective suppression in pastures and fields. Large-scale agricultural applications often exceed $15 per acre annually, though two-step methods combining baits and mound drenches can reduce long-term outlays by targeting colonies efficiently. In , fire ant-related agricultural damages alone topped $90 million in 1999, underscoring the persistent fiscal strain despite ongoing research into cost-effective controls.

Human Health Effects

Stings from Solenopsis invicta workers deliver a venom primarily composed of piperidine alkaloids, including , causing immediate intense burning pain at the site, followed by , , and pruritus. Within 24 hours, a characteristic sterile pustule forms, which typically persists for 3 to 8 days and may lead to secondary bacterial infections if scratched. Multiple stings are common due to the ants' aggressive swarming behavior, exacerbating local tissue damage and discomfort. In approximately 20% of cases, stings provoke large local reactions extending beyond the immediate area, while 0.5% to 2% trigger systemic IgE-mediated responses ranging from generalized urticaria to life-threatening involving , laryngeal , and cardiovascular collapse. Sensitization prevalence in infested regions can reach levels where fire ant stings pose the primary hymenopteran risk for adults, with recommended for those with prior severe reactions. Annual sting incidence in endemic U.S. areas affects 38% to 51% of residents, contributing to thousands of medical consultations and emergency visits. Fatal outcomes, though rare, occur predominantly via in vulnerable populations such as children under 20, the elderly, and individuals with comorbidities; surveys of U.S. physicians have documented 83 such deaths, with accounting for over 25% of reported cases. Non-allergic complications include from massive envenomations and toxic effects from venom overload, particularly in infants or those unable to escape swarms. No significant association exists between stings and long-term issues like anxiety or depression in affected populations.

Predators and Natural Controls

Native and Introduced Predators

In their native range across southern , populations of Solenopsis invicta are regulated by a suite of natural enemies, including generalist predators such as armadillos, which consume by excavating mounds. These vertebrates contribute to limiting colony expansion, though the ' aggressive stinging defense restricts extensive predation by larger animals. Other potential native predators include by competing ant species and opportunistic consumption by birds, but quantitative data on their impact remains limited, with fire ants exhibiting lower dominance compared to invasive ranges due to overall biotic pressures. To mitigate invasive S. invicta in regions like the , biological control programs have introduced specialist predators from the native range, primarily phorid flies (Pseudacteon spp.). These flies target foraging workers, inducing antipredator behaviors that reduce colony foraging efficiency by up to 50% in affected areas. The U.S. Department of Agriculture initiated releases in 1995, with five Pseudacteon species targeting different ant sizes; the first successful establishment occurred with P. tricuspis in in 1997. By 2011, these flies had established across millions of acres in states including , Georgia, and , demonstrating spread and reproduction in the field. Similar introductions have occurred in and other invaded regions, though establishment success varies and full population suppression has not been achieved without integration with other controls. No other non-native vertebrate or macro-invertebrate predators have been widely introduced due to risks of non-target effects.

Parasites and Pathogens

The microsporidian Kneallhazia solenopsae (synonym Thelohania solenopsae) is a prominent of Solenopsis invicta, primarily targeting the tissue of larvae, pupae, and adults, leading to reduced , impaired queen , and colony decline. In its native South American range, varies by social form, with surveys of 559 colonies across 15 Argentine sites revealing higher rates in polygyne (multiple-queen) colonies compared to monogyne (single-queen) ones, attributed to increased worker exchange facilitating . Efforts to introduce K. solenopsae for biological control in the United States since the 1990s have shown limited field establishment and impact, possibly due to environmental mismatches and low in introduced populations lacking co-adapted host resistance. Another microsporidian, Vairimorpha invictae, similarly infects South American fire ant populations, causing chronic infections that weaken vigor but has not been widely pursued for importation biocontrol. Viruses such as Solenopsis invicta virus 1 (SINV-1) and SINV-3 represent significant pathogens, with SINV-1 inducing acute infections that spread rapidly via trophallaxis, often resulting in complete colony mortality within weeks. In U.S. populations, SINV-1 reached 4.2% in sampled colonies as of 2025, while SINV-3 alters behavior, elevates larval and pupal mortality, and suppresses worker activity, though both viruses exhibit variable influenced by host genotype and environmental stressors. Metagenomic surveys in native ranges have identified additional viral candidates, but importation risks and host specificity concerns have curtailed their use in control programs. Entomopathogenic fungi, including Metarhizium anisopliae and , occur naturally at low levels in fire ant mounds, penetrating the to cause mycosis and death, with isolation rates around 9.4% in soil samples. These fungi show promise in laboratory assays but face challenges in field applications due to requirements and UV degradation, limiting their role as standalone natural regulators compared to synthetic formulations tested for . Overall, while native-range pathogens exert selective pressure—evident in higher polygyne colony infections—their reduced prevalence in invasive U.S. populations underscores an "enemy release" , complicating biocontrol .

Management Strategies

Chemical Controls

Chemical controls for fire ants primarily rely on insecticide baits, which exploit the ants' behavior by incorporating slow-acting toxicants into food attractants such as or corn grit carriers; foragers carry the bait back to the colony, distributing it to the queen, brood, and workers for colony-wide elimination. These baits achieve 80-90% colony mortality when applied correctly, though complete eradication is rare due to reinvasion from untreated areas. Broadcast application over infested areas is recommended for large-scale management, often followed by targeted mound treatments in a "two-step method" to address surviving colonies. Hydramethylnon, a metabolic inhibitor that disrupts energy production in , is a widely used toxicant in products like Amdro, providing visible reductions in foraging activity within 1-2 weeks and peak control at 4-6 weeks post-application. , a phenylpyrazole that blocks GABA-gated channels leading to hyperexcitation and , offers comparable or superior with lower environmental risks; granular baits at 0.00025-0.014% concentrations yield over 80% mortality in field trials after 6-12 weeks. Spinosad, derived from soil bacteria and approved for organic use, targets nicotinic receptors and achieves similar colony suppression, though it may require higher doses for equivalent speed. Mound-specific treatments involve drenching or injecting contact insecticides like or directly into nests, which kill on contact but offer shorter residual control (weeks) and higher risks to non-target organisms compared to baits. Application success depends on timing—ideally during active in warm, dry conditions ( temperatures above 21°C/70°F)—and avoiding rain, which dilutes baits; improper use can lead to sublethal exposure and bait aversion. While effective for short-term suppression, chemical controls alone do not prevent reinfestation, necessitating integration with other strategies, and regulatory approvals by the EPA ensure labeled products minimize off-target effects on pollinators and .

Biological and Physical Methods

Biological control methods for fire ants primarily involve the introduction of insects and the conservation of competitive ant species. The most established agents are phorid flies (Pseudacteon spp.), small native to that target imported fire ants (Solenopsis invicta and S. richteri). These flies lay eggs on worker ants, with larvae developing inside the ant's head, eventually decapitating the host upon pupation. Multiple species, including P. tricuspis and P. curvatus, have been released in the United States since the early , establishing self-sustaining populations that spread naturally at rates of up to 2-5 km per year in suitable habitats. Field studies indicate these flies reduce fire ant activity by 30-50% in areas of high fly density, altering ant through induced "zombie" states where parasitized ants avoid trails and mounds, thereby decreasing colony efficiency and competitive dominance over . However, phorid flies alone do not eradicate colonies, achieving only partial suppression, as evidenced by persistent fire ant densities in release sites despite multi-species introductions. Conservation of native and non-native ant competitors, such as Solenopsis geminata or Pheidole spp., represents a complementary biological approach by fostering interspecific antagonism that limits fire ant expansion. These ants prey on fire ant reproductives, raid small colonies, and compete for resources, with preservation efforts emphasizing management to avoid broad-spectrum insecticides that disrupt these dynamics. Experimental releases and monitoring in and have shown that diverse ant communities correlate with 20-40% lower fire ant mound densities compared to monocultures. Pathogens like the microsporidian Kneallhazia solenopsae and nematodes (Heterorhabditis spp.) have been tested but exhibit variable efficacy, infecting 10-30% of ants in lab settings yet failing to achieve field-level population reductions without repeated applications. Physical methods rely on mechanical disruption or environmental stress to destroy colonies without chemicals, though they are labor-intensive and best suited for isolated . Excavation involves digging up the , typically 30-60 cm deep, and transferring and to a sealed for disposal, with talcum applied to tools to deter ant adhesion; success rates reach 80-90% for single mounds when are located and removed, but satellite colonies often necessitate follow-up treatments. drenches, applied at 2-4 gallons per mound during active seasons (spring-fall), kill 50-60% of surface but penetrate poorly to deeper chambers, yielding overall control of only 20-30% without repetition every 7-10 days. These techniques risk stings from disturbed and are impractical for large infestations, with studies recommending integration with baits for enhanced outcomes. Novel approaches like hot air injection or have shown promise in trials, achieving 70-95% mortality in contained tests, but remain unscaled due to equipment costs.

Integrated Pest Management and Challenges

Integrated pest management (IPM) for red imported fire ants (Solenopsis invicta) combines monitoring, prevention, biological agents, and targeted chemical applications to suppress populations sustainably, prioritizing disruption over complete eradication. Monitoring entails regular for mounds in vulnerable sites such as playgrounds, athletic fields, and crop edges to gauge infestation levels and guide interventions. Cultural practices, including turf maintenance via appropriate mowing heights (2-3 inches), , and fertilization, enhance competitive native ant species and reduce fire ant dominance. The cornerstone chemical strategy is the two-step method: initial broadcast application of slow-acting baits (1-2 pounds per acre) at 1-2 ounce mounds per density, targeting workers that deliver toxins to , followed by drench treatments on surviving mounds using contact insecticides. Effective baits incorporate insect growth regulators like , , or spinosad, applied during optimal periods (evenings, spring-fall) for 80-90% reduction in mound numbers within 8-12 weeks. Biological integrations, such as releases of phorid flies (Pseudacteon spp.), disrupt by inducing escape behaviors and reducing worker efficiency, with USDA evaluations showing enhanced suppression when combined with low-rate baits. Challenges persist due to the ants' polygynous colony forms, where multiple queens enable supercolony networks spanning hectares, fostering rapid recolonization and territorial expansion that undermine localized treatments. Reinfestation from untreated adjacent areas necessitates coordinated community-wide programs, as isolated efforts yield temporary relief followed by resurgence. Emerging issues include bait aversion, where ants learn to avoid toxic forages with effects lasting up to 30 weeks, and low-level insecticide resistance, such as 2-fold tolerance to pyrethroids like beta-cypermethrin, complicating chemical reliance and requiring active ingredient rotation. Certain biological options, like nematodes, prove ineffective owing to desiccation and poor mound penetration. Sustained IPM demands adaptive strategies, including improved water-resistant baits and expanded natural enemy releases, to counter these adaptive pest traits.

References

  1. https://www.cabidigitallibrary.org/doi/full/10.1079/cabicompendium.50569
  2. https://www.nature.com/articles/s41598-018-32327-z
  3. https://www.antwiki.org/wiki/Solenopsis_invicta
  4. https://www.invasivespeciesinfo.gov/terrestrial/invertebrates/red-imported-fire-ant
  5. https://www.sciencedirect.com/science/article/pii/S2095311918620143
  6. https://www.invasive.org/gist/moredocs/solinv01.pdf
  7. https://www.aaaai.org/tools-for-the-public/conditions-library/allergies/fire-ant-allergy
  8. https://www.mdpi.com/2414-6366/9/4/69
  9. https://pmc.ncbi.nlm.nih.gov/articles/PMC7017801/
  10. https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecs2.4075
  11. https://ant-pests.extension.org/classification-of-fire-ants/
  12. https://edis.ifas.ufl.edu/publication/IN352
  13. https://www.invasive.org/browse/subinfo.cfm?sub=4675
  14. https://bugguide.net/node/view/30188
  15. https://ant-pests.extension.org/fire-ant-nomenclature-and-terminology/
  16. https://www.thoughtco.com/what-are-fire-ants-1968080
  17. https://www.antwiki.org/wiki/Solenopsis
  18. https://animalia.bio/red-imported-fire-ant
  19. https://texasinsects.tamu.edu/red-imported-fire-ant/
  20. https://ipm.ucanr.edu/TOOLS/ANTKEY/redimport.html
  21. https://pmc.ncbi.nlm.nih.gov/articles/PMC3834273/
  22. https://lgpress.clemson.edu/publication/educators-guide-to-managing-red-imported-fire-ants-solenopsis-invicta-in-school-or-community-vegetable-gardens/
  23. https://www.sciencedirect.com/science/article/pii/0022191090900125
  24. https://academic.oup.com/aesa/article-abstract/103/4/678/166427
  25. https://pubmed.ncbi.nlm.nih.gov/15841219/
  26. https://www.cambridge.org/core/journals/bulletin-of-entomological-research/article/carriers-and-cutters-sizedependent-caste-polyethism-in-the-tropical-fire-ant-solenopsis-geminata/A15E582C19B5C411DF18D27C4DD9ECEB
  27. https://www.bio.fsu.edu/~tschink/publications/1995-5.pdf
  28. https://www.lsuagcenter.com/articles/page1636498198280
  29. https://www.sciencedirect.com/science/article/abs/pii/S0040816602000265
  30. https://pmc.ncbi.nlm.nih.gov/articles/PMC3385716/
  31. https://extension.msstate.edu/insects/fire-ants/fire-ant-biology
  32. https://content.ces.ncsu.edu/biology-behavior-of-red-imported-fire-ant-rifa
  33. https://agriculture.okstate.edu/departments-programs/entomol-plant-path/research-and-extension/red-imported-fire-ants/site-files/documents/rifabiology2-1.pdf
  34. https://ipm.ucanr.edu/PMG/PESTNOTES/pn7487new.html
  35. https://pmc.ncbi.nlm.nih.gov/articles/PMC3738511/
  36. https://www.bio.fsu.edu/~tschink/publications/1983-1.pdf
  37. https://academic.oup.com/beheco/article-pdf/9/3/301/566603/9-3-301.pdf
  38. https://www.orkin.com/pests/ants/fire-ants/fire-ant-life-cycle
  39. https://www.fireants.org.au/look/biology/lifecycle
  40. https://fireants.tennessee.edu/about-fire-ants/biology/
  41. https://academic.oup.com/ee/article/35/1/167/375136
  42. https://www.ars.usda.gov/arsuserfiles/60360510/publications/Vander_Meer_et_al-1992%28M-2727%29.pdf
  43. https://www.bio.fsu.edu/~tschink/publications/1993-3.pdf
  44. https://www.bestantsuk.com/post/monogyne-vs-polygyne-ants-the-hidden-truth-about-ant-colony-structure
  45. https://www.sciencedirect.com/science/article/abs/pii/S0022201106000826
  46. https://academic.oup.com/aesa/article/96/1/86/31200
  47. https://www.ars.usda.gov/arsuserfiles/60360510/publications/Tennant_and_Porter-1991%28M-2551%29.pdf
  48. https://pmc.ncbi.nlm.nih.gov/articles/PMC10294795/
  49. https://jes.kglmeridian.com/view/journals/ents/26/4/article-p450.xml
  50. https://ui.adsabs.harvard.edu/abs/2007AcEcS..27..855Y
  51. https://www.ars.usda.gov/arsuserfiles/60360510/publications/Kafle_et_al-2009%28M-5010%29.pdf
  52. https://pmc.ncbi.nlm.nih.gov/articles/PMC3391925/
  53. https://link.springer.com/article/10.1023/A:1020835304713
  54. https://www.bio.fsu.edu/~tschink/publications/1981-3.pdf
  55. https://pmc.ncbi.nlm.nih.gov/articles/PMC6348953/
  56. https://www.sciencedirect.com/science/article/pii/S004268222300051X
  57. https://www.nature.com/articles/s41598-018-31969-3
  58. https://www.osha.gov/sites/default/files/publications/fire_ants.pdf
  59. https://pmc.ncbi.nlm.nih.gov/articles/PMC10467070/
  60. https://www.sciencedirect.com/science/article/abs/pii/S0041010103002757
  61. https://ipm.ucanr.edu/home-and-landscape/red-imported-fire-ant/pest-notes/
  62. https://www.researchgate.net/publication/227225390_Defensiveness_of_the_fire_ant_Solenopsis_invicta_is_increased_during_colony_rafting
  63. https://www.ars.usda.gov/arsuserfiles/60360510/publications/Vander_Meer-1987%28M-1687%29.pdf
  64. http://extension.msstate.edu/content/fire-ant-biology
  65. https://pmc.ncbi.nlm.nih.gov/articles/PMC12387039/
  66. https://fieldstations.utexas.edu/research/invasive-species-research/fire-ant-research
  67. https://www.jstor.org/stable/25083857
  68. https://www.pnas.org/doi/10.1073/pnas.95.24.14232
  69. https://pubmed.ncbi.nlm.nih.gov/40411443/
  70. https://pmc.ncbi.nlm.nih.gov/articles/PMC8932086/
  71. https://esajournals.onlinelibrary.wiley.com/doi/10.1890/07-0659.1
  72. https://www.sciencedirect.com/science/article/abs/pii/S0048969725022843
  73. https://academic.oup.com/aesa/article-abstract/67/1/43/73061
  74. https://onlinelibrary.wiley.com/doi/10.1155/2012/198084
  75. https://www.inaturalist.org/guide_taxa/850294
  76. https://www.pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/444/444-284/ENTO-342.pdf
  77. https://pubmed.ncbi.nlm.nih.gov/18305962/
  78. https://www.ars.usda.gov/is/pr/2009/090702.htm
  79. https://ant-pests.extension.org/natural-enemies-of-fire-ants/
  80. https://www.ars.usda.gov/ARSUserFiles/oc/br/fireants/publications/EE26_373.pdf
  81. https://ipmworld.umn.edu/lockley
  82. https://fireant.tamu.edu/learn/history-of-the-red-imported-fire-ant/
  83. https://encyclopediaofalabama.org/article/imported-fire-ants/
  84. https://www.aphis.usda.gov/plant-pests-diseases/ifa
  85. https://www.outbreak.gov.au/current-outbreaks/red-imported-fire-ant
  86. https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecs2.4652
  87. https://www.researchgate.net/publication/367468044_Analysis_on_new_occurrence_records_of_red_imported_fire_ant_Solenopsis_invicta_Buren_in_China_in_2021
  88. https://www.researchgate.net/publication/341332820_Eradication_and_Control_Strategies_for_Red_Imported_Fire_Ants_Solenopsis_invicta_in_Taiwan
  89. https://www.researchgate.net/publication/392537285_Invasive_Fire_Ants_Potential_Area_of_Distribution_in_the_South-Eastern_Balkans_by_2050
  90. https://www.researchgate.net/publication/347432520_Mapping_the_Potential_Global_Distribution_of_Red_Imported_Fire_Ant_Solenopsis_invicta_Buren_Based_on_a_Machine_Learning_Method
  91. https://www.ars.usda.gov/ARSUserFiles/oc/br/fireants/publications/E83_2337.pdf
  92. https://www.airies.or.jp/attach.php/6a6f75726e616c5f32382d32656e67/save/0/0/28-2_08.pdf
  93. https://www.fireants.org.au/dangers/impacts/environment
  94. https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1050&context=ncfwrustaff
  95. https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1046&context=ncfwrustaff
  96. https://fireant.tamu.edu/learn/impact-of-the-red-imported-fire-ant/
  97. https://www.ucdavis.edu/news/invading-ants-disrupt-ecosystem
  98. https://ant-pests.extension.org/management-of-imported-fire-ants-in-livestock-production-systems/
  99. https://www.ars.usda.gov/research/publications/publication/?seqNo115=391182
  100. https://www.ars.usda.gov/ARSUserFiles/60360510/publications/Adams_et_al-1988%28M-2010%29.pdf
  101. https://www.pubs.ext.vt.edu/444/444-284/444-284.html
  102. https://www.ars.usda.gov/arsuserfiles/60360510/publications/Adams_et_al-1976%28M-1056%29.pdf
  103. https://www.researchgate.net/profile/Eduardo_Segarra/publication/308971896_Spatial_Economic_Impacts_of_the_Red_Imported_Fire_Ant_on_Major_Agricultural_Crops_in_Texas_Texas_Tech_University_College_of_Agricultural_Sciences_and_Natural_Resources_Publication_No_T-1-507_67_pgs_Lu/links/57fbe83b08ae329c3d497e56/Spatial-Economic-Impacts-of-the-Red-Imported-Fire-Ant-on-Major-Agricultural-Crops-in-Texas-Texas-Tech-University-College-of-Agricultural-Sciences-and-Natural-Resources-Publication-No-T-1-507-67-pgs.pdf
  104. https://txjanr.agintexas.org/index.php/txjanr/article/view/166
  105. https://www.ars.usda.gov/news-events/news/research-news/2025/fire-ants-may-offer-insight-into-crippling-honey-bee-disease/
  106. https://extension.msstate.edu/publications/control-fire-ants-commercial-fruits-nuts-and-vegetables
  107. https://fireants.tennessee.edu/management/agricultural-control/
  108. https://ant-pests.extension.org/fire-ant-control-the-two-step-method-and-other-approaches/
  109. https://ant-pests.extension.org/wp-content/uploads/2019/09/Statewide_RIFA_TX.pdf
  110. https://agriculture.okstate.edu/departments-programs/entomol-plant-path/research-and-extension/red-imported-fire-ants/site-files/documents/rifahealthhaz2.pdf
  111. https://medlineplus.gov/ency/article/002843.htm
  112. https://lubbock.tamu.edu/files/2015/10/ENTO_005.pdf
  113. https://www.jacionline.org/article/S0091-6749%2803%2901075-3/fulltext
  114. https://www.annallergy.org/article/S1081-1206%2813%2900485-7/pdf
  115. https://pubmed.ncbi.nlm.nih.gov/2760357/
  116. https://pmc.ncbi.nlm.nih.gov/articles/PMC6016926/
  117. https://invasives.org.au/meet-the-invaders/fire-ants/
  118. https://edis.ifas.ufl.edu/publication/IN1174
  119. https://www.ars.usda.gov/news-events/news/research-news/2011/new-red-imported-fire-ant-enemies-in-place-for-combat/
  120. https://pmc.ncbi.nlm.nih.gov/articles/PMC3281391/
  121. https://www.ars.usda.gov/ARSUserFiles/60360510/publications/Flanders_et_al-2008%28M-4294%29.pdf
  122. https://pmc.ncbi.nlm.nih.gov/articles/PMC10743500/
  123. https://www.sciencedirect.com/science/article/abs/pii/S0022201125000229
  124. https://myrmecologicalnews.org/cms/index.php?option=com_download&view=download&filename=volume21/mn21_101-116_printable.pdf&format=raw
  125. https://bioone.org/journals/florida-entomologist/volume-95/issue-2/024.095.0242/The-Fire-Ant-Hymenoptera--Formicidae-Pathogen-Vairimorpha-invictae-Microsporidia/10.1653/024.095.0242.full
  126. https://www.ars.usda.gov/arsuserfiles/60360510/publications/Oi_and_Valles-2008%28M-4361%29.pdf
  127. https://academic.oup.com/ee/article/54/3/553/8119840
  128. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0192377
  129. https://www.researchgate.net/publication/303849788_Fungi_Associated_with_Solenopsis_invicta_Buren_Red_Imported_Fire_Ant_Hymenoptera_Formicidae_from_Mounds_in_Mississippi
  130. https://www.ars.usda.gov/arsuserfiles/60360510/publications/Williams_and_deShazo-2004%28M-3897%29.pdf
  131. https://tellus.ars.usda.gov/stories/articles/improving-effectiveness-fire-ant-bait
  132. https://journals.flvc.org/flaent/article/download/74843/72501/75047
  133. https://ant-pests.extension.org/broadcast-baits-for-fire-ant-control/
  134. https://ant-pests.extension.org/fire-ant-treatment-organic-insecticides/
  135. https://entomology.ces.ncsu.edu/red-imported-fire-ant/
  136. https://sfyl.ifas.ufl.edu/lawn-and-garden/sustainable-fire-ant-control/
  137. https://www.aphis.usda.gov/sites/default/files/imported_fireant_ea_march2012.pdf
  138. https://www.sciencedirect.com/science/article/abs/pii/S1049964420307362
  139. https://scijournals.onlinelibrary.wiley.com/doi/10.1002/ps.70038
  140. https://cals.cornell.edu/integrated-pest-management/outreach-education/fact-sheets/fire-ant-decapitating-fly-pseudacteon-spp
  141. https://fireants.tennessee.edu/treatment-methods/
  142. https://fieldreport.caes.uga.edu/publications/B1191/managing-imported-fire-ants-in-urban-areas/
  143. https://www.ars.usda.gov/arsuserfiles/60360510/publications/Flanders_et_al-2008%28M-4294%29.pdf
  144. https://ant-pests.extension.org/managing-imported-fire-ants-in-urban-areas/
  145. https://schoolipm.tamu.edu/forms/pest-management-plans/ipm-action-plan-for-fire-ants/
  146. https://www.ars.usda.gov/southeast-area/gainesville-fl/cmave/imported-fire-ant-and-household-insects-research/docs/imported-fire-ant-integrated-pest-management-ipm-project-at-fort-jackson-south-carolina/
  147. https://fireant.tamu.edu/learn/biology/
  148. https://www.nature.com/articles/s42003-025-07818-1
  149. https://pmc.ncbi.nlm.nih.gov/articles/PMC9583148/
  150. https://ipm.ifas.ufl.edu/community/Beneficial_Nematodes_Not_Effective_for_Fire_Ant_Control.shtml
Add your contribution
Related Hubs
User Avatar
No comments yet.