Tanipone

Known only from Madagascar, Tanipone are terrestrial ants of arid and semi-arid habitats that are occasionally found on low vegetation.

Identification
Bolton & Fisher (2012) - In addition to the characters noted in the diagnosis of the genus, workers of all known species of Tanipone have 2–3 projecting setae on the leading edge of the scape. Also, in all species the eyes are located at the broadest point of the head and the outer eye margins always break the outlines of the sides. In front of the eyes the sides of the head are weakly convex and distinctly convergent anteriorly; behind the eyes the sides converge weakly towards the posterior corners. Predominant surface sculpture in all species is of punctures, usually shallow and weakly foveolate but sometimes coarse and very closely packed, sometimes small and widely spaced. No other basic form of sculpture is known. Superficial microsculpture may occur between the punctures.

Borowiec (2016) - Worker Tanipone workers are distinctive ants with large eyes and ocelli, very long palps and unique glandular patches on abdominal segment III. The latter are present in all species except one (Tanipone aglandula). The body coloration is black or bicolored reddish and black, with a light band or two light spots present at the posterior edge of abdominal segment III. The workers of Tanipone lack a conspicuous mid tibial spur. Other genera without the spur include Simopone and Vicinopone. Additionally, in certain species of Lioponera the mid tibial spur may be reduced and not easily discernible. Tanipone workers can be easily distinguished from all three lineages by remarkably long palps that are always visible on preserved specimens, reaching the occipital foramen.

Male The male of Tanipone is also easily distinguished from all other dorylines by the long maxillary palps, almost always extruded and reaching occipital foramen. The wing venation is variously developed but the submarginal cell (SMC) is open or closed by a faint 2rs-m cross-vein. There are no notauli and no spurs on middle tibiae.

Species Groups

 * Tanipone species groups

Distribution
Endemic to Madagascar.

Biology
Borowiec (2016) - The known specimens have been collected mostly in a variety of drier habitats in Madagascar, including dry tropical forest, savannah, and spiny forest. Most workers were collected on low vegetation, on the ground or in rot holes on tree trunks. The sole nest sample of Tanipone (Tanipone zona) was collected under a stone. Nothing is known about feeding habits of this lineage. The putative queen specimens are ergatoid. Based on nest collections where larvae of different sizes and pupae were collected together, known for Tanipone hirsuta, Tanipone subpilosa, and T. zona, brood development appears not synchronized.

Nomenclature

 *  TANIPONE [Cerapachyinae: Cerapachyini]
 * Tanipone Bolton & Fisher, 2012: 75. Type-species: Tanipone hirsuta, by original designation.

Worker
Shared characters of the genera Simopone, Vicinopone and Tanipone - As well as the 20 features that are exhibited by all members of Cerapachyini these three genera share the following suite of seven characters in the worker caste. None of the characters is claimed as synapomorphic for the three, or for any two of the three.

1 Pretarsal claws with a single preapical tooth, at least on the metatarsus.

2 Mesotibial spurs absent (at most a setiform vestige may remain that cannot be distinguished by light microscopy from other setae at the tibial apex).

3 Metatibial spur single, pectinate.

4 Eyes present and conspicuous, always large (EL/HW 0.30–0.53).

5 Apical antennomere subcylindrical, not inflated and bulbous.

6 Ventrolateral margin of head without a continuous longitudinal carina that commences close to anterior margin below the mandible and extends the entire length of the head to the posterior margin (a carina is present posterolaterally that usually extends onto the ventral surface).

7 Frontal lobes widely separated by the relatively broad clypeus; frontal lobes not or only slightly elevated laterally on each side of the clypeus (never closely approximated and vertical).

A Malagasy genus of predominantly terrestrial cerapachyine ants, but also quite frequently found on low vegetation. With the shared characters of Cerapachyini listed in the introduction and also with the following combination of characters. Two apomorphies of the genus are in italics.

1 Palp formula 6,4. Maxillary palps extremely long: with mouthparts retracted the apices of the maxillary palps, when extended back on underside of head, extend beyond the level of the posterior margin of the eye and usually approach the occipital foramen.

2 Antenna with 12 segments, tapering apically and not incrassate; apical antennomere subcylindrical and tapering apically, not swollen and bulbous, no broader than the preapical segment.

3 Scape short (SI 49–65), when laid straight back in full-face view the apex of the scape excedes the level of the anterior margin of the eye but never reaches the level of the posterior margin of the eye.

4 Eyes large (EL/HW 0.37–0.48), located slightly behind the midlength of the head.

5 Ocelli present.

6 Clypeus more or less flat between the slightly elevated frontal lobes; frontal carinae very short, constricted and terminating almost immediately behind the frontal lobes.

7 Parafrontal ridges short and indistinct, weakly developed.

8 Head capsule with a short, vertical posterior surface above the occipital foramen, that meets the vertex through a blunt angle; vertex behind ocelli usually with a very fine, low transverse ridge.

9 Head capsule, in ventral or ventrolateral view, with a carina that extends down the posterolateral margin and onto the ventral surface where it passes through a near right-angle and extends to the ventral midline.

10 Mesosoma dorsally without trace of the promesonotal suture; metanotal groove vestigial to absent.

11 Pronotum in dorsal view rounded anteriorly between anterior surface and dorsum, not transversely marginate nor carinate; propodeum marginate or carinate between dorsum and declivity, even if only weakly so.

12 Mesopleuron with a strongly developed transverse sulcus.

13 Mesotibia without spurs (a setiform vestige is usually visible).

14 Metatibia with a single, pectinate spur.

15 Metatibial gland present, its orifice usually small and indistinct.

16 Metabasitarsus ventrally without a longitudinal glandular groove.

17 Pretarsal claws of at least the metatarsus with a single, small, preapical tooth on the inner surface of each claw.

18 Propodeal lobe in profile small, rounded apically.

19 Propodeal spiracle orifice small, circular.

20 AII (petiole) not marginate laterally in dorsal view.

21 AIII not postpetiolate, in dorsal view more voluminous than AII but only a little smaller than AIV.

22 ''Tergite of AIII with a pair of subovate glandular patches on the posterior half. Posterior margin of segment with a transverse band of pale cuticle, or a pair of pale patches, that subtend the glands''.

23 Prora of AIII a small, simple, convex cuticular boss or prominence, not delimited by a sharp curved carina that separates the anterior face of the poststernite from the lateral and ventral surfaces.

24 Pretergite of AIV in dorsal view not strongly constricted with respect to posttergite of AIV.

25 Cinctus of AIV either with or without cross-ribs.

26 Pygidial denticles sparse, restricted to a short apical arc along a narrow prominence at the extreme apex of the sclerite.

Comments on worker characters

Numbers correspond to character numbers above.

1 Palp formula 6,4 has been confirmed by in situ counts of fully extended mouthparts of all species, and also by dissection of Tanipone hirsuta, Tanipone maculata, Tanipone pilosa, Tanipone varia and Tanipone zona. The extreme elongation of the palps, especially the maxillaries, is not matched in any other cerapachyine, or any other dorylomorph, genus.

9 The carina in Tanipone is very similar to that seen in Vicinopone, and quite different from the carina as developed in Simopone. In that genus the carina extends onto the ventral surface but terminates or fades out well before meeting the ventral midline.

13 As in Simopone, the mesotibial apex usually has one to several setae that are roughly aligned with the long axis of the tibia. In Tanipone one of these setae almost certainly represents the last vestige of a spur.

15 When a visible orifice of the metatibial gland is discernible, it generally appears as a slightly depressed, small, subovate patch or pore, located posterior to the small cuticular vesicle at the base of the spur and usually off the ventral midline of the metatibia. The orifice is variously developed in different species of the genus. In aglandula it is a shallow elongate depression; in aversa, Tanipone cognata, Tanipone pilosa, Tanipone scelesta, Tanipone subpilosa and Tanipone varia it forms a subcircular to subovate patch or pore; in Tanipone hirsuta there is no obvious pore, but a small patch of pale cuticle is present. In the two very closely related species Tanipone maculata and Tanipone zona, no orifice can usually be seen, but an inconspicuous minute pore occurs in some workers. Variation of this nature is not surprising and is replicated elsewhere. For instance, in the two closely related West African Lioponera  species, Lioponera foreli and Lioponera nkomoensis, the gland orifice is a shallow oval pore in the former, but an elongate deep slit, often filled with whitish flocculent material, in the latter.

17 Unlike in Simopone, the extra tooth on each pretarsal claw is usually not uniformly present on every leg in the various species of Tanipone. On the metatarsus the preapical teeth of the pretarsal claws are most commonly present; they are always conspicuous in Tanipone aglandula, Tanipone hirsuta and Tanipone pilosa, and small but usually distinct in Tanipone cognata and Tanipone maculata. However, in some species they may be minute and difficult to discern (Tanipone aversa), and sometimes appear to be absent (e.g. not discernible in some specimens of Tanipone scelesta and Tanipone zona, and many specimens of Tanipone varia). On the mesotibial claws a small extra tooth is uncommon; most specimens have the claws simple, although an extra tooth has been seen in some specimens of aglandula, hirsuta, Tanipone maculata and pilosa. Protibial claws are almost always simple; a small tooth has been clearly detected only in a couple of specimens of hirsuta.

20 Anterior surface of AII slopes posteriorly in profile. The anterior and dorsal surfaces, and the dorsal and posterior surfaces, are separated by blunt angles or weak transverse carinae; the posterior margin in dorsal view is usually shallowly concave medially. The side of AII tergite has a longitudinal carina above the level of the spiracle.

22 In a single species, aglandula, the glandular patches are not visible on the surface of AIII by light microscopy, but the characteristic pale area that subtends the glands and appears associated with them is strongly retained. Whether the glands remain present beneath the tergite, or whether they have atrophied and been entirely lost in this species, remains to be seen. Whichever, it is most parsimonious to assume apparent modification or loss of the paired gland in aglandula, rather than to assume its individual development in every other species of the genus. The pale band, or pair of pale spots, at the apex of tergite AIII is conspicuous in all species save for a few specimens of scelesta, where it may be very faint or even absent, but in these few specimens the glandular patches themselves remain conspicuous.

24 In dorsal view the maximum width of the pretergite of AIV is 0.76–0.89 × the maximum width of the posttergite of the segment. This is relatively much wider than in Simopone (0.52–0.69) and Vicinopone (0.62–0.64). The ratio has not yet been investigated in other cerapachyine genera.

25 When cross-ribs are present on the cinctus they are very short, indistinct, fine and crowded.

Borowiec (2016) - Head: Antennae with 12 segments. Apical antennal segment not enlarged, not broader and longer than two preceding segments combined. Clypeus without cuticular apron. Lateroclypeal teeth absent. Parafrontal ridges reduced. Torulo-posttorular complex vertical. Antennal scrobes absent. Labrum with median notch or concavity. Proximal face of stipes projecting beyond inner margin of sclerite, concealing prementum when mouthparts fully closed. Maxillary palps 6-segmented. Labial palps 4-segmented. Mandibles triangular, edentate. Eyes present, composed of more than 20 ommatidia. Ocelli present. Head capsule with differentiated vertical posterior surface above occipital foramen. Ventrolateral margins of head without lamella or ridge extending towards mandibles and beyond carina surrounding occipital foramen. Posterior head corners dorsolaterally immarginate. Carina surrounding occipital foramen ventrally present. Mesosoma: Pronotal flange not separated from collar by distinct ridge. Promesonotal connection with suture completely fused. Pronotomesopleural suture visible, unfused up to notal surface. Mesometapleural groove deeply impressed, conspicuous. Transverse groove dividing mesopleuron present. Pleural endophragmal pit concavity present. Mesosoma dorsolaterally immarginate. Metanotal depression or groove on mesosoma absent or a weakly impressed line. Propodeal spiracle situated low on sclerite. Propodeal declivity with distinct dorsal edge or margin and rectangular in posterior view. Metapleural gland without bulla visible through cuticle. Propodeal lobes present, well developed. Metasoma: Petiole anterodorsally marginate, dorsolaterally immarginate, and laterally above spiracle marginate. Helcium in relation to tergosternal suture placed at posttergite and axial. Prora simple, not delimited by carina. Spiracle openings of abdominal segments IV–VI circular. Abdominal segment III anterodorsally immarginate and dorsolaterally immarginate. Abdominal segment III more than half size of succeeding segment IV, which is weakly constricted at presegmental portion (uninodal waist). Girdling constriction of segment IV present, i.e. pre- and postsclerites distinct. Cinctus of abdominal segment IV gutter-like, not sculptured. Cinctus of abdominal segment IV gutter-like and smooth or cross-ribbed. Abdominal segment IV not conspicuously largest segment. Abdominal tergite IV not folding over sternite, and anterior portions of sternite and tergite equally well visible in lateral view. Girdling constriction between pre- and posttergites of abdominal segments V and VI absent. Girdling constriction between pre- and poststernites of abdominal segments V and VI present or absent. Pygidium large, with weakly impressed medial field, and armed with few modified setae restricted to apex. Hypopygium unarmed. Legs: Mid tibia without spurs. Hind tibia with single pectinate spur. Hind basitarsus not widening distally, circular in cross-section. Posterior flange of hind coxa not produced as raised lamella. Metatibial gland present as oval patch of whitish cuticle. Metabasitarsal gland absent. Hind pretarsal claws each armed with a tooth. Polymorphism: Monomorphic.

Queen
PUTATIVE ERGATOID GYNE

No standard alate/dealate queens with any trace of developed flight sclerites have been discovered for any species of Tanipone. However, in Tanipone cognata, Tanipone scelesta and Tanipone maculata a few specimens (1, 1, and 2, respectively) are distinctly more densely sculptured. In particular, they possess a very conspicuous, fine, dense microreticulation between the punctures on the dorsal mesosoma. In scelesta and maculata, these specimens differ from their otherwise identical workers only in this feature: in maculata a graded increment of sculpture appears to link specimens with the weakest sculpture to those with the strongest. The specimen of cognata is a singleton which, disregarding the mesosomal sculpture, does not otherwise resemble any known worker. It may be that these more heavily sculptured forms represent a rare upper limit of worker sculptural variation within each species of the maculata group. Yet the possibility that they may represent separate species cannot be dismissed. However, it is suspected that these rare forms do not represent separate species or densely sculptured workers, but are in fact extreme ergatoid gynes; they therefore exhibit all the characters of the worker diagnosis at genus rank. Only dissection of the ovaries and spermathecae of these oddities will reveal the truth of the matter, but material suitable for such a detailed examination is not presently available.

Male
Males caught in association with workers are known only for Tanipone zona. In are many unassociated males retrieved from light traps, where they appear to be reasonably common. These have not been treated in detail as regards species-rank taxonomy, but have been utilised to make the diagnosis of this sex as complete as possible.

1 Palp formula 6,4; the maxillary palps, when laid back along the underside of the head, reach or very nearly reach the occipital foramen.

2 Mandibles triangular and edentate, masticatory margins meeting at full closure; masticatory margins straight to shallowly concave.

3 Antenna 13-segmented, filiform; funicular segments 3 to apex longer than broad; apical segment tapering apically and not swollen, slightly longer than funicular segment 12 but no broader.

4 Eyes large and very conspicuous.

5 Ocelli present.

6 Frontal lobes short and convergent posteriorly, not concealing the antennal sockets in full-face view; frontal carinae short or very short, abruptly terminated posteriorly.

7 Head capsule, in ventral or ventrolateral view, with a carina that extends down the posterolateral margin and onto the ventral surface, where it abruptly curves medially and extends to the ventral midline.

8 Pronotum visible anteriorly in dorsal view as a narrow collar in front of the mesoscutum.

9 Notauli absent.

10 Parapsidal grooves present but often feebly developed.

11 Propodeal lobes present and conspicuous.

12 Mesotibia without spurs (a setiform vestige is usually present).

13 Metatibia with a single, pectinate spur.

14 Pretarsal claws with or without a preapical small tooth.

15 Venation as discussed below.

16 Prora present as a small lobe or short transverse crest.

17 AIII not postpetiolate; in dorsal view AIV > AIII, the two broadly articulated; AIII > AII.

18 Glandular patches absent from tergite of AIII.

19 Pygidium with posterior margin not denticulate.

Comments on male characters

Numbers correspond to character numbers above.

1 The palp formula of 6,4 has been seen in every specimen examined in which the mouthparts were extended and can even be counted in many specimens in which the mouthparts are fully retracted. The maxillary palps are as disproportionately elongated as in the workers and ergatoids.

9 No traces of notauli remain on the mesosocutum, in marked contrast to Simopone males, where notauli are very strongly developed.

10 In the majority of specimens parapsidal grooves are present on each side of the mesoscutum as fine, faint impressions. In a few specimens they are extremely faint and not easy to see.

14 In a single unassociated male a small preapical tooth is present on the pretarsal claws of the mesotarsus and metatarsus but absent from the protarsus. In zona and other males examined a tiny preapical tooth is often apparent on the metatarsal claws but is sometimes absent. The claws of the mesotarsi are predominantly simple, with only a tiny or vestigial tooth in some; the protarsal claws always appear simple.

15 The most complete forewing venation is shown by an unassociated male from Morondava, in UCDC (P.S. Ward#11112-7), from a light trap. The pterostigma is large and pigmented; C is absent and R1•f3 is absent distal of the pterostigma; pigmented tubular veins are represented only by Sc+R, Sc+R1, Rs•f1, M+Cu, M•f1, cu-a, and A to just distal of cu-a. The remaining veins are depigmented but mostly tubular, the long veins tend to fade distally: Rs+M, M and Cu are distinct, but Rs•f2-3 is absent and Rs•f4-5 fades out just before reaching the margin. Crossveins cu-a (which always arises from M+Cu), 1m-cu and 2rs-m are present and easily visible, but 2r-rs is faint. Most specimens show reductions from this pattern, with various veins disappearing, but a large, pigmented pterostigma is always retained. In many specimens 2rs-m is lost, leaving a “stigmal vein” (= 2r-rs&Rs•f4-5) dependent from the pterostigma; but often this is very faint and may also be lost. In the most reduced forewings only a framework of weak veins in the proximal half of the wing membrane remains, consisting of Sc+R, Sc+R1, Rs•f1, M•f1, M+Cu and the basal portion of A.

Borowiec (2016) - Head: Antennae with 13 segments. Clypeus without cuticular apron. Parafrontal ridges absent. Torulo-posttorular complex vertical. Maxillary palps 6-segmented. Labial palps 4-segmented. Mandibles triangular, edentate. Ventrolateral margins of head without lamella or ridge extending towards mandibles and beyond carina surrounding occipital foramen. Carina surrounding occipital foramen ventrally present. Mesosoma: Pronotal flange separated from collar by distinct ridge or not. Notauli absent. Transverse groove dividing mesopleuron present. Propodeal declivity with distinct dorsal edge or margin. Metapleural gland opening absent. Propodeal lobes present. Metasoma: Petiole anterodorsally immarginate, dorsolaterally immarginate, and laterally above spiracle marginate. Helcium in relation to tergosternal suture placed at posttergite and axial. Prora forming a simple U-shaped margin or U-shaped protrusion. Spiracle openings of abdominal segments IV–VI circular. Abdominal segment III more than half size of succeeding segment IV; latter weakly constricted at presegmental portion (uninodal waist). Girdling constriction of segment IV present, i.e. pre- and postsclerites distinct. Cinctus of abdominal segment IV gutter-like and cross-ribbed. Girdling constriction between pre- and postsclerites of abdominal segments V and VI absent. Abdominal segment IV not conspicuously largest segment. Abdominal sternite VII simple. Abdominal sternite IX distally armed with two spines, with lateral apodemes about as long as medial apodeme, directed anteriorly (towards head). Genitalia: Cupula long relative to rest of genital capsule and shorter ventrally than dorsally. Basimere broadly fused to telomere, with no sulcus trace at junction, and ventrally with left and right arms separated. Telomere gradually tapering toward apex. Volsella gradually tapering toward apex. Penisvalva laterally compressed, rounded at apex. Legs: Mid tibia without spurs. Hind tibia with single pectinate spur. Posterior flange of hind coxa not produced as raised lamella. Metatibial gland absent. Metabasitarsal glands absent. Hind pretarsal claws simple. Hind pretarsal claws each armed with a tooth. Wings: Tegula present, broad, demiovate in shape. Vein C in fore wing absent. Pterostigma broad. Abscissa R·f3 absent. Abscissae Rs·f2–3 absent. Cross-vein 2r-rs absent, present and forming base of ‘free stigmal vein’ (2r-rs&Rs·f4–5) in absence of Rs·f3 and 2rs-m, or present and connected to Rs·f2–3&Rs·f4. Abscissae Rs·f4–5 absent or differentiated into Rs·f4 and Rs·f5 by 2rs-m. Abscissa M·f2 in fore wing absent or contiguous with Rs+M. Abscissa M·f4 in fore wing absent or present, reaching wing margin. Cross-vein 1m-cu in fore wing absent or present. Cross-vein cu-a in fore wing present, arising from M+Cu and proximal to M·f1. Vein Cu in fore wing present, with only Cu1 branch prominent. Vein A in fore wing with only abscissa A·f1 present or with abscissae A·f1 and A·f2 present. Vein C in hind wing absent. Vein R in hind wing absent. Vein Sc+R in hind wing present. Abscissa Rs·f1 in hind wing present, as long as 1rs-m or longer than 1rs-m. Abscissa Rs·f2 in hind wing absent or present, reaching wing margin. Cross-vein 1rs-m in hind wing absent or present, about as long as M·f1. Vein M+Cu in hind wing present. Abscissa M·f1 in hind wing present. Abscissa M·f2 in hind wing absent. Cross-vein cu-a in hind wing absent or present. Vein Cu in hind wing present. Vein A in hind wing abscissa A·f1 or with abscissae A·f1 and A·f2 present.

Larva
Cocoons absent.