Hypoponera

Small ants that are generally found at or just under the ground surface. They nest in rotten wood, the leaf litter, under ground objects and in the soil.

Identification
See the nomenclature section below for diagnostic characters.

Key, description of, and species in the Afrotropical and West Palaearctic Hypoponera species groups.

Castes
Monomorphic workers. Queens are known to be produced as a winged and distinctive form in many Hypoponera. Intermediate worker-queen ergatoid forms are also known for some species. Males are the least well known of all the castes but it is believed that most species only produce what would be thought of as typical males. Ergatoid males have been found in a limited number of species.

Intercastes have been confirmed in the following species that occur in the Afrotropical region. H. abeillei group: Hypoponera austra, Hypoponera importuna, Hypoponera lepida, Hypoponera producta. H. punctatissima group: Hypoponera eduardi, Hypoponera ragusai, Hypoponera punctatissima. Possible intercastes are also suspected in Hypoponera ignavia and Hypoponera occidentalis (see discussions of those species). It seems reasonable to assume that intercastes occur in many more species but are not currently represented in collections. It is equally obvious that some species, such as the extremely common Hypoponera dulcis, do not produce them. In some previous publications, intercastes have been termed major workers or ergatoid females (e.g. Forel (1894), Le Masne (1956), Brown (1958)).

Nomenclature

 *  HYPOPONERA [Ponerinae: Ponerini]
 * Hypoponera Santschi, 1938b: 79 [as subgenus of Ponera]. Type-species: Ponera abeillei, by original designation.
 * Hypoponera raised to genus: Taylor, 1967a: 9.

Worker
Bolton and Fisher (2011) - Members of subfamily Ponerinae, tribe Ponerini (sensu Bolton, 2003) that principally inhabit rotten wood, leaf litter and topsoil.

1 Mandible triangular and stout, short to moderate in length (MI 27–35), without a basal groove and without a basal pit; with a basal angle between masticatory and basal margins. When mandibles are fully closed there is no space between the masticatory margins, nor between basal margins of mandibles and the clypeus.

2 Masticatory margin of mandible with 7 to about 18 teeth and denticles in total.

3 Palp formula 1,1 or 1,2, the maxillary palp usually minute.

4 Clypeus simple, without extended lobes or teeth on either the median or the lateral portions and usually unarmed anteromedially. Median portion of clypeus inserted as a small narrow triangle between the extreme anterior ends of the frontal lobes.

5 Frontal lobes small, almost confluent medially, separated only by a median longitudinal impression; the frontal lobes not raised or specialised in any way and their anterior margins well behind the anterior clypeal margin. Frontal carinae and antennal scrobes absent.

6 Eyes absent or present; when present always small (generally of 1 to about 20 ommatidia), lateral and located well in front of the midlength of the head.

7 Antenna with 12 segments, the apical 4–6 antennomeres gradually incrassate; only extremely rarely with a sharply differentiated club.

8 Dorsum of mesosoma with or without a metanotal groove.

9 Mesopleuron without a distinct transverse sulcus that conspicuously divides it into anepisternum and katepisternum.

10 Epimeral sclerite usually absent.

11 Metapleural gland orifice small and simple, opening posteriorly.

12 Metasternal process small and simple.

13 Propodeal spiracle small, circular to slightly elliptical, located far down on the side, usually close to the bulla of the metapleural gland.

14 Propodeum unarmed; propodeal lobes vestigial to absent.

15 Mesotibiae, metatibiae, mesobasitarsi and metabasitarsi all without spines and without enlarged prominent setae to enhance traction on their dorsal (outer) surfaces.

16 Mesotibia and metatibia each with only a single spur; metatibial spur always pectinate.

17 Pretarsal claws small and simple, without preapical teeth.

18 Petiole tergite nodiform to squamiform, always unarmed.

19 Subpetiolar process usually simple, a rounded to angulate ventral lobe; never with paired prominent teeth at the posteroventral corner of the lobe; subpetiolar process usually without an anterior fenestra or thin-spot but a fenestra present in some abeillei group members.

20 Articulation of petiole to helcium simple.

21 Helcium arises low down on anterior face of first gastral tergite (Abd. III) and is always simple; anterior surface of first gastral tergite forms a tall vertical surface above the helcium.

22 Prora usually present (absent in only one Afrotropical species): an arched tranverse crest that extends across the first gastral sternite below the helcium; usually the prora extends up the anterior face of the first sternite on each side, so that the entire prora is broadly U-shaped in anterior view.

23 Cinctus of second gastral tergite (Abd. IV) present, usually conspicuous.

24 Stridulitrum absent or present on pretergite of abdominal segment IV. In addition, fine sculpture is predominantly present, uncommonly entirely absent. The sculpture is expressed as various forms of punctation, that varies in density and intensity on different parts of the body and sometimes differs between species. Coarse, dense sculpture, such as rugae, costulae, or strong striation, appears never to be developed.

Queen
Bolton and Fisher (2011) - Characters as listed for workers except for worker characters 6, 8, 9; with the following differences. 1 Eyes always present and large, usually obviously with > 50 ommatidia. Eyes are located in front of midlength of head and all species examined have small setae that project between the ommatidia.

2 Ocelli present.

3 Mesopleuron with a well developed transverse suture that divides it into anepisternum and katepisternum.

4 Mesosoma with a full complement of flight sclerites (alate when virgin).

5 Jugal lobe absent from hindwing.

6 Venation almost complete (only cross-vein 1r-rs absent); with 8 or 9 closed cells including the pterostigma (8 cells in those species with Cu2 incomplete or absent); Rs.f5 meets R1.f3 on the anterior margin (i.e. marginal cell always closed); cross-veins 2r-rs, 2rs-m, 1m-cu and cu-a all present; cu-a arises from M+Cu (i.e. proximal of point where M+Cu divides into M and Cu; 2rs-m distal of 2r-rs; a free abscissa of M (M.f2) present between Rs+M and 1m-cu; an angle or bend sometimes present in Rs.f2&3; a fenestra present in cu-a and fenestrae sometimes visible in Rs.f2&3 and 2rs-m, but not in minute species.

7 Petiole node in profile is usually more slender, and often more tapered dorsally, than in the conspecific worker.

Generally slightly larger than conspecific worker; gaster sometimes distinctly larger.

ergatoid queen

Characters as worker but always with much larger eyes than conspecific worker (intercastes with 7–30 ommatidia in Afrotropical species in which workers have 0–7 ommatidia), but without ocelli; often with a shorter petiole node in profile and a somewhat enlarged gaster; sometimes with a gyne-like transverse sulcus on mesopleuron. One intercaste of Hypoponera punctatissima was dissected: a spermatheca was present and the ovaries were enlarged, though much smaller than in the gyne (see also Yamauchi, et al. (1996)).

Male
Bolton and Fisher (2011):

1 Mandible lobiform to unidentate (apical tooth only present), not meeting at full closure. Basal cavity of mandible extends to its front face and is visible in full-face view.

2 Eyes large and conspicuous, with minute setae projecting from between the ommatidia. Three distinct ocelli present.

3 Antenna with 13 segments, filiform.

4 Scape short, shorter than second funicular segment.

5 Second funicular segment longer than the first and also longer than the third.

6 Palp formula 1,1; 1,2; 1,3; 1,4; very rarely maxillary palp of 2 segments.

7 Mesonotum in profile not overhanging pronotum.

8 Mesoscutellum convex in profile.

9 Notauli absent; parapsidal grooves present but sometimes very faint.

10 Epimeral sclerite absent.

11 Mesotibia and metatibia each with a single spur; metatibial spur always pectinate.

12 Pretarsal claws simple.

13 Venation as alate gyne.

14 Jugal lobe absent from hindwing.

15 Petiole unspecialised ventrally; helcium very low on anterior face of first gastral segment.

16 Prora present, small.

17 Cinctus of second gastral tergite (Abd. IV) present.

18 Tergite of abdominal segment VIII (pygidium) without a median downcurved spine.

19 Pygostyles (= cerci) present.

ergatoid male

1 Body form extremely worker-like but male genitalia present.

2 Mandibles reduced (similar to alate males) or worker-like.

3 Antenna with 12 or 13 segments, worker-like or specialised but without the basal segment arrangement of alate males (male characters 4 and 5, above). Scape distinctly shorter than in conspecific worker.

4 Eyes present or absent.

The characters above are based on Hypoponera eduardi, Hypoponera punctatissima and Hypoponera ragusai, but ergatoid males are also produced by Hypoponera opacior, Hypoponera opaciceps and Hypoponera nubatama.

At first glance ergatoid males can easily be mistaken for workers, especially as the characteristic male genitalia are retractile and may be almost entirely concealed within the body. The ergatoid male of H. eduardi is monomorphic, with reduced mandibles, 13-segmented antennae and small eyes present. The ergatoid male of punctatissima is dimorphic. Both morphs have worker-like mandibles and head shape and 12-segmented antennae, but the larger morph is brown and has small eyes, while the smaller morph is yellow and lacks eyes. Ergatoid males of ragusai have not yet been found in the Afrotropical region, but specimens from the U.S.A. have a worker-like head and mandibles, as punctatissima, but possess 13-segmented antennae.

Additional References

 * [[Media:Bolton & Fisher 2011.pdf|Bolton, B. & Fisher, B.L. 2011. Taxonomy of Afrotropical and West Palaearctic ants of the ponerine genus Hypoponera Santschi. Zootaxa 2843: 1-118. PDF]]