Orthemis

Hagen, 1861

Tropical King Skimmers

Orthemis is a of large in the , commonly known as Tropical Skimmers. The genus is primarily Neotropical in distribution, with approximately 28 described . Males are typically red in coloration while females are . The genus exhibits notable chromosomal diversity, including the highest number recorded in (2n=41 in O. nodiplaga) and a neo-XY sex-determination system in O. ambinigra. The complete has been described for O. ferruginea, which includes 17 larval .

Orthemis discolor by (c) John Rosford, some rights reserved (CC BY), uploaded by John Rosford. Used under a CC-BY license.

Orthemis ferruginea by no rights reserved, uploaded by Steve Wells. Used under a CC0 license.

Orthemis ferruginea by (c) Don Loarie, some rights reserved (CC BY). Used under a CC-BY license.

Pronunciation

How to pronounce Orthemis: //ˈɔr.θɛ.mɪs//

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Identification

Males distinguished by generally red coloration; females by coloration. Specific identification to level requires examination of morphological details including abdominal patterning, , and in some cases chromosomal features. O. ferruginea males are notably hot pink in mature coloration. Females of O. ferruginea have a distinct flare near the tip of the and differ markedly from males in appearance.

Images

Habitat

Aquatic and semi-aquatic environments including marshes, wetlands, ponds, and temporary pools. O. schmidti collected from small temporary muddy-bottomed puddles approximately 1.5 m × 1 m × 0.20 m deep. O. ferruginea found in muddy, shrinking wetlands.

Distribution

Neotropical region. Seven of 28 described reported from Argentina. Specific collection records from Misiones and Buenos Aires provinces (Argentina), Maranhão (northeastern Brazil), and New Mexico (USA) for O. ferruginea.

Diet

of O. ferruginea fed nauplii of Artemia franciscana during early (F-15 to F-8), and larvae of and during later instars (F-7 to F-0).

Life Cycle

with , larval (), and stages. O. ferruginea has 17 larval from through F-0. Larval from F-0 to F-16 averaged 186 days under laboratory conditions (26-30°C). Eggs hatch in controlled conditions; require aquatic environment. involves meiotic stages from spermatogonial prometaphase through metaphase II with characteristic including bouquet arrangement at early prophase I.

Ecological Role

Predatory as , feeding on aquatic including mosquito and larvae. are aerial . O. schmidti larvae co-occurred with other including Erythrodiplax fusca, Pantala flavescens, Erythrodiplax basalis, Miathyria marcella, Orthemis discolor, Perithemis lais, and Erythemis plebeja.