Discothyrea oculata, Emery, 1901

Hita-Garcia, Francisco, Lieberman, Ziv, Audisio, Tracy L., Liu, Cong & Economo, Evan P., 2019, Revision of the Highly Specialized Ant Genus Discothyrea (Hymenoptera: Formicidae) in the Afrotropics with X-Ray Microtomography and 3 D Cybertaxonomy, Insect Systematics and Diversity 5, pp. 1-84 : 9

Discothyrea oculata Species Complex

Diagnosis

Frontal carinae produced as a broad, elevated plate, rhomboid in frontal view, roof-like in profile; deep scrobal area present, defined medially and anteriorly by the lateral margins of the frontal carinae, extending posteriorly to just anterad the eyes; AT3 much longer than AT4 (ASI 46–60; Fig. 2A ; eyes present and well developed, with multiple domed ommatidia, eyes protruding from head (even if weakly so); eyes sometimes large; sculpture very coarse, predominately alveolate to foveate; ventrolateral surface of head with two rounded to subconical tumuli; ventral head surface posteromedially flattened, with reduced to absent sculpture; mesal face of mandible with row of large, broadened setae; petiole broadly disciform to hemispherical in profile, anterior face gently curved, not dorsally anteroposterioly attenuated, subcircular in anterior view; AS 3 with anterior concavity bordered anteriorly by prora.

[See Fig. 5 A–D for illustrations of diagnostic characters given above.]

Notes

The oculata -complex is represented in Africa by two species only: D. mixta and D. oculata . Despite this low number of species compared with the D. traegaordhi complex, both species are very widespread and have the broadest distribution ranges within the genus in this region ( Fig. 4A and B ). This distinctive complex is the only group present in Madagascar and is well represented in the Oriental and Indomalayan regions, while it is completely absent in the New World. Interestingly, the only species of Discothyrea for which detailed natural history data are available ( D. kamiteta , D. mixta , D. oculata ) are species of this complex. It is possible that the distinctive morphology of the complex, particularly the shape of the frontal carinae, deep scrobes and the modified mandibular setae, the deeply alveolate or areolate sculpture, the proportion of abdominal segments 3 and 4, and the anterior development of abdominal sternite 3, is related to oophagy and claustral lestobiotic colony foundation.

Figures

Fig. 2. Still images generated from surface display volume renderings of petiole and gaster showing different proportions of abdominal segments III (in orange) and IV (in blue). (A) D. mixta, (B) D. kalypso, (C) D. venus.

Fig. 5. Still images from surface display volume renderings displaying the general morphology of both species complexes. Discothyrea oculata complex, D. mixta (CASENT0285473): (A) head in full-face view, (B) head in profile, (C) head in ventral view, (D) body in profile. Discothyrea traegaordhi complex, D. wakanda (CASENT0790326): (E) head in full-face view, (F) head in profile, (G) head in ventral view, (H) body in profile.

Fig. 4. Maps showing the known distribution ranges of Afrotropical Discothyrea species.