Orthemis

Hagen, 1861

Tropical King Skimmers

Species Guides

Orthemis discolor(carmine skimmer)
Orthemis ferruginea(Roseate Skimmer)
Orthemis

Orthemis is a of large in the Libellulidae, commonly known as Tropical King Skimmers. The genus is primarily Neotropical in distribution, with approximately 28 described . Males are typically red in coloration while females are brown. The genus exhibits notable chromosomal diversity, including the highest number recorded in Odonata (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 instars.

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//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Males distinguished by generally red coloration; females by brown coloration. Specific identification to level requires examination of morphological details including abdominal patterning, wing venation, 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 larvae 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

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

Life Cycle

Complete with , larval (naiad), and stages. O. ferruginea has 17 larval instars from prolarva through F-0. Larval from F-0 to F-16 averaged 186 days under laboratory conditions (26-30°C). Eggs hatch in controlled conditions; larvae 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 larvae, feeding on aquatic including mosquito and larvae. are aerial . O. schmidti larvae co-occurred with other Odonata including Erythrodiplax fusca, Pantala flavescens, Erythrodiplax basalis, Miathyria marcella, Orthemis discolor, Perithemis lais, and Erythemis plebeja.