Belongs to a group of medium-sized anisopteran odonates, characterized by a total body length ranging between 30 and 35 millimeters. Mature males develop a striking, dark pruinose blue-black coloration covering the abdomen and thorax, while their most diagnostic physical feature is the presence of a distinct, dark-brown to black patch at the apex of each hyaline wing. In contrast, females and immature individuals display a lighter yellowish-brown ground color with dark lateral stripes on the abdomen, and their wings are mostly clear, sometimes possessing only a diffuse, pale amber tint at the base. The head features large compound eyes that meet broadly at the dorsal midline, showing a dark reddish-brown hue in fully mature specimens.
Geographical distribution: Is widely distributed across the temperate and subtropical regions of southern South America. Its presence is thoroughly documented throughout Argentina, particularly in the central and northern provinces such as Buenos Aires, Córdoba, Santa Fe, and Entre Ríos. Additionally, its geographical range extends across the entire territory of Uruguay, southern Brazil (specifically within the states of Rio Grande do Sul and Santa Catarina), and various wetland systems in Paraguay.
Habitat: Primarily colonizes lentic freshwater systems, showing a strong preference for permanent and temporary ponds, marshes, swamps, sluggish streams, and lake margins. This species exhibits remarkable ecological plasticity, frequently inhabiting disturbed and peri-urban environments such as artificial reservoirs, drainage ditches, and ornamental ponds in city parks, provided there is sufficient emergent or floating aquatic vegetation to support their perching and breeding requirements.
Feeding: Functions as a highly effective, opportunistic generalist predator in both its aquatic and aerial life stages. As adults, they hunt on the wing, capturing a wide variety of small flying insects such as mosquitoes, midges, flies, and small moths. The aquatic nymphs, or naiads, are cryptic predators that utilize a specialized prehensile labium to ambush prey among benthic debris and submerged vegetation, consuming dipteran larvae, microcrustaceans, and occasionally tiny tadpoles.
Behavior: Males exhibit prominent territorial and heliophilic behavior, actively selecting elevated perches like reeds, twigs, or tall grasses near the water´s edge. From these vantage points, they monitor their territory, aggressively chasing away conspecific males and intercepting incoming females. During peak temperature hours around midday, they adopt the obelisk posture, raising their abdomen vertically toward the sun to minimize surface area exposure and regulate their body temperature.
Reproduction: The mating sequence begins with a rapid aerial pursuit, leading to the formation of the characteristic copulatory wheel. Once copulation is completed—often while perched on shoreline vegetation—the female performs exophytic oviposition. She hovers close to the water surface, repeatedly dipping the tip of her abdomen into the water to wash off and deposit her eggs over submerged plants or muddy substrates. During this process, the male typically performs non-contact guarding, hovering closely nearby to fend off rival males and ensure the female completes egg deposition undisturbed. The aquatic larvae undergo multiple molts before climbing onto emergent vegetation to undergo their final emergence.
Conservation status: Is currently not listed under any high-risk threat categories globally, being generally regarded as a species of Least Concern (LC). Its high tolerance to habitat modification and its ability to colonize human-made wetlands buffer it against localized habitat loss, although excessive chemical pollution from agricultural runoff remains a localized threat to larval survival in farming regions.
Compilation and publication: EcoRegistros – 12/09/2026