Represents a medium to large-sized dragonfly species with a highly pronounced sexual dimorphism. Adult males of Orthemis nodiplaga exhibit an eye-catching bright red to magenta-red coloration on their abdomen and thorax, which becomes deeper and slightly pruinose with age. Their compound eyes are large and characterized by a dark reddish-brown hue. The wings are mostly transparent, except for a distinct dark brown patch situated at the base of the hindwings near the nodus, serving as a key diagnostic feature. Females and immature specimens display much more cryptic coloration, being mostly yellowish-brown or ochre with pale longitudinal stripes along the thorax. The wingspan of the adults ranges between 70 to 80 millimeters, and the total body length is approximately 45 to 52 millimeters.

Geographical distribution: Occurs widely across the Southern Cone of South America. It is well-documented and highly abundant throughout Argentina, ranging from the warm northern provinces down to the temperate Pampas region. It is also native to Uruguay, southern Brazil, and various low-lying regions of Paraguay, making it one of the most frequently observed libellulids within its distribution range.

Habitat: Prefers lentic freshwater environments, being commonly found in permanent ponds, temporary pools, marshes, drainage ditches, and slow-moving river bends. It shows high ecological plasticity and frequently colonizes human-modified landscapes, such as artificial reservoirs, urban parks, agricultural ponds, and flooded quarries, provided there is sufficient emergent vegetation.

Feeding: Is an obligate carnivore throughout its entire life cycle. Adults are highly agile aerial predators that hunt on the wing, consuming vast quantities of flying insects including mosquitoes, midges, flies, small moths, and occasionally smaller dragonflies. The aquatic nymphs are ambush predators that rely on an extensible hinged labium to capture aquatic insect larvae, small crustaceans, tadpoles, and even tiny fish fry.

Behavior: Exhibits strongly heliophilic habits, with maximum activity levels recorded during warm, sunny hours. Males are fiercely territorial and aggressive, utilizing prominent perches such as twigs, reeds, or fence posts near the water´s edge to monitor their territory. They perform rapid, darting flights to chase away rival males and immediately return to their preferred perches.

Reproduction: Commences with the formation of a mating tandem in flight, followed by a brief copulation period that takes place either in the air or while perched on nearby foliage. Oviposition is exophytic; the female hovers close to the water surface, rhythmically tapping her abdomen against the water to release eggs. During this process, the male typically performs non-contact mate-guarding, hovering closely to protect her from rival males. The eggs hatch into aquatic nymphs which undergo several instars over several months before emerging for final metamorphosis.

Conservation status: Classified as Least Concern (LC) on the IUCN Red List. This status is justified by its extensive geographic range, stable population dynamics, and remarkable capacity to utilize and thrive in artificial or moderately disturbed aquatic habitats.