Strumigenys ants are specialized predators on small, soft-bodied arthropods. They wait for prey with their mandibles opened wide (at least 170°) and when prey is encounterd specialized hairs found on the ant's mouthparts trigger a forceful snap of the mandibles. This rapid and explosive strike is generally enough to kill the prey, and it is not necessary to sting the prey. These ants are common in warmer climates but are seldom seen due to their small size, slow movements and cryptic life in the leaf-litter and soil.
(Bolton 2000): Cephalic dorsum with a single pair of short erect hairs, simple to narrowly spatulate, close to the occipital margin; mesonotum with a pair of long erect flagellate hairs; first gastral tergite with long wavy flagellate hairs; ventral surface of petiole without a trace of spongiform tissue.
Natural history: One of the most common Strumigenys species in forests of Cachoeira reserve.
(Bolton 2000): Mandible with spiniform tooth separated from apicodorsal tooth by a distance at least equal to its length; scape with an obtuse but pronounced sub-basal bend; apicoscrobal hair absent; pronotal humeral hair long and fine but meso-notum without standing hairs; propodeal declivity with a broad lamella that is angulate at top & bottom; lateral lobe of petiolar node conspicously spongiform.
second record for S. gytha; first record for Paraná.
(Bolton 2000): Apical fork of mandibles with 2 intercalary denticles; mandible with a preapical tooth located near the apicodorsal tooth; apicoscrobal hair short and stiff, remiform; cephalic dorsum with a single pair of short standig hairs, close to occipital margin; pronotal humeral hair fine and flagellate; mesonotal standing hairs remiforms; propodeum with a pair of teeth subtended by a narrow lamella on the declivity, without a sharp tooth or spine at base of declivity; ventral surface of petiole without spongiform tissue.
The distribution area of S. louisianae ist vast and ranges from Southern USA to Argentina. It is extremely variable in color, sculpture and size. Bolton (2000) comments on this with "the variation remains impenetrable and I strongly suspect that more than one, and maybe several, genuine species are currently concealed in louisianae.
S. louisianae is restricted to open habitats and early stages of forest regeneration at Cachoeira Nature reserve.
Offline References for Strumigenys
Bolton, B. (2000): The Ant Tribe Dacetini. Memoirs of the American Entomological Institute. Vol. 65, part 1-2.
Brown, W. L. (1962): The neotropical species of the ant genus Strumigenys Fr. Smith: Synopsis and keys to the species. Psyche 69:238-267.