Linepithema humile

Linepithema humile, the Argentine ant. Davis, California, USA

Linepithema humile

An Argentine ant tends citrus scale insect for honeydew. Davis, California, USA

Linepithema humile

Argentine ants tending scale insects on an orange tree in suburban California. Davis, California, USA

Linepithema humile

The infamous Argentine Ant. California, USA

Linepithema humile

A trail of Argentine ants. Davis, California, USA

Linepithema humile

A queen and worker Argentine ant, Linepithema humile. Córdoba, Argentina

Linepithema humile

Argentine ants fighting. Argentine ants typically form large supercolonies comprising millions of ants and thousands of nests. Within these massive supercolonies fighting is rare, but ants from neighboring supercolonies readily attack each other. Córdoba, Argentina

Workers tend to a queen in a laboratory colony of Argentine Ants (Linepithema humile). California, USA

Argentine ants (Linepithema humile), an aggressive pest species introduced by human commerce to California, attack a native Pogonomyrmex harvester ant. Native ants in many places around the world have disappeared in areas invaded by Argentine ants. Davis, California, USA

A feisty little Argentine ant (Linepithema humile) attacks a much larger fire ant (Solenopsis invicta). Both species co-exist naturally in subtropical South America, but in the southern United States where both have been accidentally introduced, the fire ant has displaced the Argentine ants. Austin, Texas, USA

Linepithema humile

Argentine ants (Linepithema humile), an aggressive pest species introduced by human commerce to California, attack a native Pogonomyrmex harvester ant. Native ants in many places around the world have disappeared in areas invaded by Argentine ants. Davis, California, USA

A worker and queen Argentine ant, Linepithema humile. Córdoba, Argentina

The odd insect at right is a male ant. He looks nothing like his sisters, bearing wings and large eyes to better serve his role of dispersal and mating. Davis, California, USA

An Argentine Ant (Linepithema humile) drinking. California, USA

Linepithema humile, the Argentine ant, queen and worker in the species' native range. Córdoba, Argentina

Linepithema humile

Argentine ants have spread from their native South America to conquer ecoystems around the world. This colony has taken over a beach in Victoria, Australia.Series voucher UTIC00201480.

Linepithema humile Quito, Ecuador

Linepithema humile Argentine ants tend to mealybugs. Quito, Ecuador

As a colony of subterranean termites (Reticulitermes hesperus) prepares for the annual release of winged reproductives, a predatory Argentine ant (Linepithema humile) approaches the nest for an easy protein meal. Davis, California, USA

Linepithema iniquum

Linepithema iniquum ranges from central America to northern Argentina and is recognized by the distinct "step" in its thoracic profile. Morretes, Paraná, Brazil

It looks like an old-fashioned mugging, but this photo shows a Linepithema iniquum scout being attacked after wandering into an orchid plant occupied by another colony of the same species. Maquipucuna reserve, Pichincha, Ecuador

Linepithema iniquum

Ants from neighboring colonies fight over access to an orchid plant. Maquipucuna reserve, Pichincha, Ecuador

Linepithema iniquum

An ant collects honeydew from a flat scale insect in an Ecuadorian cloud forest. Maquipucuna reserve, Pichincha, Ecuador

Linepithema iniquum

Inside the folds of an orchid plant, Linepithema iniquum ants from neighboring colonies fight over access to the plant's nectar sources. Maquipucuna reserve, Pichincha, Ecuador

Linepithema iniquum

Workers from different nests, fighting. Morretes, Paraná, Brazil

Linepithema iniquum workers from different colonies fighting. Morretes, Paraná, Brazil

Linepithema leucomelas

The distinctly-patterned Linepithema leucomelas nests at the bases of bromeliads and other epiphytic plants in Brazil's Atlantic forest region. Morretes, Paraná, Brazil

Linepithema leucomelas

The distinctly-patterned Linepithema leucomelas nests at the bases of bromeliads and other epiphytic plants in Brazil's Atlantic forest region. Morretes, Paraná, Brazil

Ground pearls are the large, sedentary adult forms of root-sap feeding insects. Here, two Eurhizococcus brasiliensis hang suspended from grape roots deep underground while a Linepithema micans ant gathers the honeydew exuded by the pearls. These insects are significant pests in Brazilian vineyards. Bento Gonçalves, Rio Grande do Sul, Brazil

Ants and scale insects are often tight ecological associates, even under the soil. Here, a first instar ground pearl (Eurhizococcus brasiliensis) is carried by a Linepithema micans worker. The ground pearls produce honeydew that feeds the ants, while the ants protect the pearls and carry their young to new host plants. Bento Gonçalves, Rio Grande do Sul, Brazil

Linepithema micans astride a ground pearl. The "pearl" is actually a honeydew-producing scale insect that feeds on the sap of roots. Bento Gonçalves, Rio Grande do Sul, Brazil

Linepithema micans running through tunnels in their underground nest. Tafí del Valle, Tucumán, Argentina

Linepithema micans, worker and eggs in an underground chamber. Bento Gonçalves, Rio Grande do Sul, Brazil

Linepithema micans Copina, Córdoba, Argentina

Linepithema micans Morretes, Paraná, Brazil

Linepithema micans eating from a bit of shortbread cookie. Myrmecologists often use cookie baits to draw ants out of their nests for study. Buenos Aires, Argentina

Linepithema oblongum

Salta, Argentina

Linepithema oblongum

Portrait of Linepithema oblongum, the sister species of the infamous Argentine ant L. humile. Little is known about the biology of this ant, in spite of its close relation to a major pest. Salta, Argentina

Portrait of Linepithema oblongum, the sister species of the infamous Argentine ant L. humile. Little is known about the biology of this ant, in spite of its close relation to a major pest. Salta, Argentina

Linepithema oblongum carrying a pupa in the brood nest. Carapunco, Tucumán, Argentina