Hadrothemis defecta, Libellulidae, is named Red Jungle-skimmer in English, and its distribution is centered on the equatorial zone. Its metallic face, black or dark thorax, and red abdomen marked with a dark ring between each segment make it impossible to confuse with any of its cousins or even another Hadrothemis.
There are seven species in the genus Hadrothemis, all African and tropical, all featuring a robust thorax. This appearance is certainly accentuated in Hadrothemis defecta by the contrast between the abdomen and the broadly dark base of its wings. We encountered 4 of the 5 known species in Ghana, and we will miss H. versuta.
Karsch tells us that the total length of this odonate reaches 40 mm, 39.5 mm for the female, which we were not lucky enough to encounter.
It is necessary to remind people from time to time that, despite what we see on our screens, dragonflies are not often "this big!" as novice witnesses report, even though they are among the largest representatives of the insect order. For comparison, a match from a small matchbox measures about 43 mm.
They are forest odonates, but like all Libellulidae, they can be found away from water in more open and sunny areas, along forest paths. Yet four species breed in sheltered forest pools, while three others oviposit in phytotelmata (tree holes), which shows a surprising diversity for the same genus.
Below, a young subject was observed briefly in an open area at the end of a forest path.
Étymologie Hadrothemis defecta
Karsch describes the species under the genus name Thermorthemis in 1891 (a), Martin in 1906 will place it in the Bolivarides, and it is Ris, in 1909, who will have it integrated into Hadrothemis, which was nevertheless created by Karsch, also in 1891 (b).
Hadrothemis, from the Greek hadros meaning strong, robust, well-developed, and Themis, the Greek goddess of order and justice, has been used many times since Hagen (1861). The name of the goddess of order is particularly well-suited to taxonomy, the science aimed at describing and ordering families, genera, and species. This suffix -themis has in fact become a signal of belonging to the Libellulidae. Karsch writes, "Kurz, plump und dick—short, heavy, and thick," which refers to its massive thorax.
Defecta, from the Latin deficere, means missing, incomplete. When describing this species in the genus Thermothemis, Karsch notes that it is the only one he knows of that lacks a vein in the triangle of the hindwing (the triangle is clear/free): "im Hinterflügel die cellula cardinalis leer…"
Karsch, 1891 a - Entomologische Nachrichten (Vol. 17, Issue 4, p. 61). (1875).
Karsch, 1891 b – [Genus Hadrothemis] Übersicht der von Herrn Dr. Paul Preuss in Deutsch-Westafrika 1890 gesammelten Odonaten. Entomologische Nachrichten, (Vol. 17, Issue 5, 65--81), p. 75.