Hypoponera dema

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Hypoponera dema
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Genus: Hypoponera
Species: H. dema
Binomial name
Hypoponera dema
Bolton & Fisher, 2011

Hypoponera dema P casent0226546.jpg

Hypoponera dema D casent0226546.jpg

Specimen Label

Nothing is known about the biology of Hypoponera dema.

Identification

A member of the abeillei group. See the nomenclature section below for identification remarks.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Rwanda (type locality), Uganda.

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Hypoponera inhabit and nest in leaf litter, the surface layer of soil, downed rotten wood, and soil around plant roots. Nests are typically found by turning objects on the ground, like downed wood and rocks, or through the ripping away of bark found on rotting downed wood or at the base of dead trees. Litter samples in tropical areas, especially in moist forested sites, often contain individuals of this genus. All Hypoponera are thought to be predators of small arthropods but published details about their diet are sparse. A lack of information about other aspects of their biology is also typical for most species.

The genus is most diverse in the tropics. Species found in higher latitudes tend to be more widespread, common and abundant than their tropical and subtropical congeners.

Castes

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • dema. Hypoponera dema Bolton & Fisher, 2011: 40, figs. 28-30 (w.q.) RWANDA.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

In the Afrotropical fauna four other species, Hypoponera molesta, Hypoponera segnis, Hypoponera tristis and Hypoponera venusta share the following set of characters with dema: metanotal groove absent; posterior surface of petiole node without cuticular ridges; cinctus of second gastral tergite with cross-ribs at base; maximum width of first gastral tergite at least equal to, and usually greater than, width of second tergite at its midlength; disc of second gastral tergite with sharply defined, distinctly separated punctures.

The smallest species in this complex are molesta and venusta, with HW 0.40–0.48, SL 0.32–0.43; the others together have HW 0.54–0.68, SL 0.46–0.61. H. molesta has a much broader petiole node (PeNI 89–94) than venusta (PeNI 76–82). In fact, molesta has the broadest node in the complex relative to its pronotal width, being approached only by some workers of dema (PeNI 82–89), but the latter is a much larger species (HW 0.64–0.68, SL 0.55–0.61) and has a sharp denticle at the midpoint of the anterior clypeal margin. The three species just mentioned all have very conspicuous standing setae on the dorsum of the first gastral tergite. These setae are quite numerous and distinct from the underlying pubescence, the setae being obviously longer and more erect. H. segnis and tristis lack these conspicuous setae. In size they are larger than molesta and venusta, having a combined HW 0.54–0.60, but are smaller than dema (HW 0.64–0.68). The petiole node is shorter in profile in segnis (LPeI 32–43) than in tristis (LPeI 46–49) and in dorsal view the node is distinctly shorter in relation to its width in segnis (DPeI 180–220) than in tristis (DPeI 154–170).

Description

Worker

(holotype in parentheses). Measurements: HL 0.78–0.84 (0.83), HW 0.64–0.68 (0.65), HS 0.715–0.760 (0.740), SL 0.55–0.61 (0.59), PrW 0.52–0.54 (0.53), WL 1.08–1.18 (1.14), HFL 0.60–0.68 (0.62), PeNL 0.26–0.29 (0.27), PeH 0.58–0.60 (0.58), PeNW 0.43–0.48 (0.46), PeS 0.423–0.450 (0.437) (9 measured). Indices: CI 78–83 (78), SI 86–92 (91), PeNI 82–89 (87), LPeI 43–48 (47), DPeI 154–185 (170).

With head in full-face view midpoint of anterior clypeal margin with sharp denticle; in profile this is seen as the apex of a raised, low but sharp cuticular longitudinal ridge. Eyes absent or present; if the latter, the eye small and poorly defined. Apex of scape, when laid straight back from its insertion, just fails to touch or just touches the mid-point of the posterior margin in full-face view; SL/HL 0.71–0.76. Cephalic dorsum densely reticulate-punctate. Lateroventral areas of head with sharply incised spaced punctures. Pronotal dorsum obviously much less strongly and densely sculptured than the cephalic dorsum. Side of pronotum, especially on curve between side and dorsum, more strongly sculptured, the puncturation on the curve slightly less dense than that seen on the head. Metanotal groove absent from dorsum of mesosoma or with a vestigial trace. Propodeum distinctly sharply marginate between declivity and side. Petiole in profile stout, its anterior face often feebly concave, so that the node increases slightly in length towards the dorsum; dorsal surface rounded. Posterior surface of petiole node without cuticular ridges that radiate upward from the peduncle. Subpetiolar process with a ventral angle. In dorsal view petiole node stout and broad, with posterior face transverse and anterior face convex. Maximum width of first gastral tergite in dorsal view distinctly greater than width of second gastral tergite at its midlength. Cross-ribs at base of cinctus of second gastral tergite conspicuous. Midline length of second gastral posttergite, from posterior margin of cinctus to apex, slightly less than the width of the segment at its midlength. Disc of second gastral tergite with sharply incised, small punctures that are separated by areas of glossy cuticle; the diameters of the punctures are equal to, or slightly less than, the distances that separate the punctures. First gastral tergite dorsally pubescent and with numerous conspicuous, standing setae that are clearly much longer and more erect than the pubescence.

Paratype Specimen Labels

Type Material

Holotype worker (top specimen of three on pin), Rwanda: Rangiro, ix.1976 (P. Werner) (Musee d'Histoire Naturelle Genève).

Paratypes. 20 workers with same data as holotype; 6 workers and 1 dealate queen Rwanda: Rangiro, 1800 m., 10.vii.1973 (P. Werner) (MHNG, The Natural History Museum, California Academy of Sciences, Barry Bolton Reference Collection)

References

  • Bolton, B. & Fisher, B.L. 2011. Taxonomy of Afrotropical and West Palaearctic ants of the ponerine genus Hypoponera Santschi. Zootaxa 2843: 1-118. PDF