.jpg){kind=logo}
Eburopone easoana
| Eburopone easoana | |
|---|---|
| |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Hymenoptera |
| Family: | Formicidae |
| Subfamily: | Dorylinae |
| Genus: | Eburopone |
| Species: | E. easoana |
| Binomial name | |
| Eburopone easoana Yamada, Nguyen & Eguchi, 2023 | |
The collecting site of the type colony series of Eburopone easoana is primarily covered with a relatively disturbed secondary evergreen forest. The collector (K. Eguchi) did not record the exact microhabitat and collecting situation of the colony fragment.
Photo Gallery
Yamada et al. (2023), Figure 3. Cranium morphology of Eburopone easoana workers, colony Eg17ix19-297, holotype (A–C, E) and nontype (D). A, head in lateral view. B, occipital corners in posterior view. C, anterior part of cranium in ventrofrontal view. D, scanning electron microscopic (SEM) photograph of anterior part of cranium in dorsofrontal view, antennae and mandibles removed (left antennal bulbus remains). E, torulo-posttorular complex and parafrontal ridges in posterior vertical view against its posterior face. Black arrows in A and C indicate a weak protrusion on lateroclypeal teeth. Abbreviations: ala – atalar acetabulum; oc – occipital carina; fl – frontal line; lct – lateroclypeal teeth; pfr – parafrontal ridge; tptc – torulo-posttorular complex.
Yamada et al. (2023), Figure 4. Cranial venter and mouthparts morphology of Eburopone easoana workers, colony Eg17ix19-297, nontypes. A, scanning electron microscopic (SEM) photograph of cranium in ventral view, mandibles removed. B, transmission light microscopic (TLM) photograph of labrum in frontal view, partly focus-stacked to emphasize lateral labral processes on caudal surface. C, TLM photograph of right maxilla in ventral view, with maxillary palpomeres indicated by black arrows. D, TLM photograph of labium in oblique lateral view, left side, with labial palpomeres indicated by black arrows. Abbreviations: oc – occipital carina; ala – atalar acetabulum; hyt – hypostomal teeth; lbrp – lateral labral process; pgr – postgenal ridge.
Yamada et al. (2023), Figure 5. Mesosoma and abdominal segments II–III morphology of Eburopone easoana workers, colony Eg17ix19-297, holotype (A, B) and non-type (C, D). A, mesosoma and abdominal segment II–III in lateral view. B, mesosoma and abdominal segment II–III in dorsal view. C, scanning electron microscopic (SEM) photograph of pronotomesopleural junction in lateral view. D, SEM photograph of promesonotum in dorsal view. Abbreviations: epp – pleural endophragmal pit; pmns – promesonotal suture.
Yamada et al. (2023), Figure 6. Abdominal segments IV–VII morphology of Eburopone easoana workers, colony Eg17ix19-297, holotype. A, abdominal segments IV–VII in dorsal view. B, abdominal segments IV–VII in ventral view, with the putative glandular patch of poststernite IV indicated by a black arrow. C, cinctus and presclerites of abdominal segment IV in dorsal view. D, abdominal tergite VII (pygidium) in dorsoposterior view.
Yamada et al. (2023), Figure 7. Habitus of dealate queens of Eburopone easoana, colony Eg17ix19-297, paratypes (all except D are of the same individual). A, head in full-face view. B, habitus in lateral view. C, habitus in dorsal view. D, abdominal segment IV–VII in ventral view, with the putative glandular patch of poststernite IV indicated by a black arrow.
,_Fig._2.jpg)
,_Fig._3.jpg)
,_Fig._4.jpg)
,_Fig._5.jpg)
,_Fig._6.jpg)
,_Fig._7.jpg)
Identification
Yamada, Nguyen, and Eguchi (2023) - Body rather bicolored: abdominal segments III–VII distinctively paler-colored than most surfaces of cranium and mesosoma. Frontal line distinct, extending a little beyond mid-length of cranium. Occipital corner in lateral view strongly produced posteriad to form conspicuous angle. Anterior (frontoclypeal) margins of torulo-posttorular complex not forming conspicuous lobes protruding over anterior clypeal margin in full-face view. Mandibles when closed in full-face view forming only a little space between anterior clypeal margin and mandibles. Promesonotal suture faint and inconspicuous. Petiole in dorsal view almost as long as or slightly longer than wide, with weakly convex lateral margins. Subpetiolar process in lateral view rounded lobate, with anterobasal margin weakly emarginate; posteroventral slope gentle, weakly concave. Abdominal segment III in dorsal view subtrapezoidal, strongly wider posteriorly, distinctly wider than long.
The worker of E. easoana' is morphologically easily distinguished from the only other valid congener Eburopone wroughtoni from southern Africa by the combination of following characteristics:
- frontal line distinct, extending a little beyond mid-length of cranium
- anterior (frontoclypeal) margins of torulo-posttorular complex not forming conspicuous lobes protruding over anterior clypeal margin in full-face view (anterior clypeal margin evenly weakly concave in full-face view)
- mandibles when closed in full-face view forming only a little space between anterior clypeal margin and mandibles (basal angles nearly reaching center line of cranium when mandibles closed)
- promesonotal suture faint and inconspicuous
- abdominal segment III in dorsal view distinctly wider than long, with lateral margins only feebly convex
The morphology of workers of E. easoana is generally consistent with the concept of Eburopone in Borowiec (2016), except for the number of labial palpomeres. Borowiec (2016) stated that both the maxillary and labial palps of Eburopone are bi-merous in workers. However, E. easoana has a bi-merous maxillary and tri-merous labial palps (Fig. 4C, D), indicating the inter-specific variation of the character within the genus. According to Borowiec (2016), in dorylines, the labial palps of workers have, as a rule, fewer palpomeres than the maxillary palps of the same individual, except for the New World army ants and Acanthostichus. Therefore, E. easoana represents a new exception against this rule. The known palp formula of Eburopone worker is updated to 2, 2 or 2, 3.
Borowiec (2016) described the condition of pronotomesopleural junction in Eburopone workers “pronotomesopleural suture visible as groove but not unfused”. However, the pronotomesopleural junction of the E. easoana workers can be interpretable as unfused in terms of the absence of sclerotized fusion, since the “groove” between the two sclerites seems membranous (Fig. 5A, C). Based on examination of the specimen images on [antweb.org AntWeb], the pronotomesopleural junction of E. wroughtoni also seems to be in the same condition.
Distribution
,_Fig._1.jpg)
Latitudinal Distribution Pattern
Latitudinal Range: 13° to 13°.
| North Temperate |
North Subtropical |
Tropical | South Subtropical |
South Temperate |
- Source: Yamada et al., 2023
Distribution based on Regional Taxon Lists
Oriental Region: Vietnam (type locality).
Distribution based on AntMaps
Distribution based on AntWeb specimens
Check data from AntWeb
Countries Occupied
| Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species. |
|
Estimated Abundance
| Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species. |
|
Biology
Castes
Nomenclature
The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.
- easoana. Eburopone easoana Yamada et al., 2023: 6, figs. 2-7 (q.w.) VIETNAM.
Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.
Description
Worker
Holotype: HL 0.63, HW 0.55, SL 0.31, WL 0.86, DML 0.73, PH 0.31, PW 0.37, MFL 0.43, PTH 0.26, PTL 0.29, PTW 0.28, A3L 0.35, A3W 0.46, A4L 0.58, A4W 0.62, CI 87, SI 50, DMI 43, DMI2 85, LMI 36, MFI 79, LPI 111, DPI 97, DA3I 131, DA4I 107.
Paratypes (N = 6): HL 0.63–0.65, HW 0.55–0.57, SL 0.31–0.33, WL 0.89–0.92, DML 0.74–0.80, PH 0.32–0.35, PW 0.37–0.40, MFL 0.44–0.47, PTH 0.27–0.29, PTL 0.30–0.33, PTW 0.29–0.32, A3L 0.37–0.43, A3W 0.47–0.51, A4L 0.56–0.64, A4W 0.64–0.66, CI 86–88, SI 48–51, DMI 42–43, DMI2 84–87, LMI 36–38, MFI 80–83, LPI 111–114, DPI 95–98, DA3I 118–130, DA4I 103–112.
Description. Worker. Body coloration. Body rather bicolored: cranium, mesosoma, and petiole, mostly dark reddish brown; antennae, anterior part of cranium, mandibles, legs, and abdominal segments III–VII paler brownish to yellowish. Pleural endophragmal pit conspicuously blackish.
Head structure. Cranium in full-face view subrectangular, 1.14–1.17× longer than wide (CI, 86–88), with convex lateral margins; posterior margin widely weakly concave. Occipital corner in lateral view strongly produced posteriad to form conspicuous angle. Occipital carina distinct and completely encircles occiput, forming inconspicuous and slightly undulate carina dorsally and a conspicuous flange lateroventrally. Frontal line distinct, extending a little beyond mid-length of cranium. Torulo-posttorular complex in full-face view arrow-like shaped with narrowed median part; anterior (frontoclypeal) margins not forming conspicuous lobes protruding over anterior clypeal margin in full-face view; maximal width of posterior arrowhead-like part a little shorter than major diameter of antennal socket. Anterior clypeal margin evenly weakly concave in full-face view. Lateroclypeal teeth large, rounded lobate, strongly protruding latero-anteriad to form anteriormost points of cranium, lateroventrally with a weak protrusion. Parafrontal ridges conspicuous and strongly elevated, turning at posteriorly to incompletely surround antennal sockets, and forming well-marginated subtriangular mound-like lobes; its lateral margins evenly rounded arc-like in full-face view; minimal distance from medialmost end of parafrontal ridge to margin of torulo-posttorular complex in full-face view as long as major diameter of antennal socket. Eye and ocelli completely absent. Antenna 12-merous; scape short, just reaching approximately mid-length of cranium when laid backward; antennomere XII distinctively longer than summed length of three preceding antennomeres IX–XI. Mandible subtriangular, with rounded obtuse basal angle and blunt apex, when closed in full-face view forming only a little space between anterior clypeal margin and mandibles (basal angles nearly reaching center line of cranium when mandibles closed); masticatory margin virtually edentate but with a series of feeble inconspicuous denticles. Postgenal ridge externally recognizable as a broad cross-ribbed furrow, ending a little before the level of occipital carina. Hypostomal teeth large and conspicuous with rounded apex in ventral view. Atalar acetabulum strongly produced anterolaterad. Labrum subrectangular with distal margin weakly bilobed with a small median notch; lateral labral process not visible in frontal view, strongly produced distad and truncated tooth-like. Maxillary palps bi-merous; palpomere II elongate, much longer than palpomere I. Labial palps tri-merous; palpomere III distinctly shorter than preceding palpomeres; palpomere II strongly curved basally.
Mesosomal structure. Mesosoma with evenly and slightly convex dorsum in lateral view; lateral margins in dorsal view almost parallel, weakly and widely compressed laterally around mesopleura. Pronotal flange only weakly marginated posteriorly from collar. Pronotum and mesopleuron unfused in terms of absence of sclerotized fusion, with dorsal part of pronotomesopleural junction apparently connected by a narrow intersegmental membrane. Promesonotal suture inconspicuous, only faintly recognizable as a shallow groove (may be hardly recognizable under normal optical observation, but the weak suture can be recognizable by changing angle of observation or lighting condition). Concavity surrounding pleural endophragmal pit deep and conspicuous. Propodeal declivity only weakly marginate dorsally, almost immarginate laterally; dorsal margin weakly arched anteriad in dorsal view. Posterodorsal corner of propodeum in lateral view blunt, only weakly angulated. Propodeal lobe evenly rounded in lateral view. Pretarsal claws simple without teeth.
Metasomal structure. Petiole (abdominal segment II) in dorsal view 1.02–1.05× longer than wide (length measured from anterodorsal corner to posterior margin of posterior petiolar peduncle; DPI, 95–98), with weakly convex lateral margins; posterior margin of posterior petiolar peduncle slightly arched anteriad. Dorsal outline of petiole in lateral view roundly convex; anterolateral petiolar carina dorsally protrude to form a stout prominence with acute apex. Subpetiolar process in lateral view rounded lobate, with anterobasal margin weakly emarginate; posteroventral slope gentle, weakly concave. Abdominal segment III in dorsal view subtrapezoidal, strongly wider posteriorly, 1.18–1.31× wider than long (DA3I, 118–131); lateral margins only feebly evenly convex; 1.59–1.62× wider than petiole. Abdominal posttergite III subrectangular in lateral view, with almost vertical anterior face; distinctly larger in height than fused poststernite III. Abdominal segment IV in dorsal view 1.03–1.12× wider than long (DA4I, 103–112), with strongly convex lateral margins. Putative glandular patch near posterior edge of abdominal poststernite IV feebly recognizable as oval pale area contrasted by little darker-colored proximate surrounding (no specialized structure such as gland opening recognizable on the external sternal surface).
Setation and sculpture. Body setation relatively sparse. Anterolateral surfaces of cranium coarsely longitudinally rugose; other areas of cranium basically smooth except having sparse seta-bearing foveae; posterolateral surfaces very smooth with few setae and sculpturing. Frontal face of labrum reticulate. Proximal face of maxillary stipes mostly smooth. Dorsum of mesosoma and petiole smooth and shiny with sparse seta-bearing foveae; pronotal flange, lateral surfaces of mesosoma and petiole shiny but superficially reticulate-imbricate; propodeal declivity and anterior face of petiole smooth. Abdominal postsclerites III and IV smooth, except sparse seta-bearing foveae. Cinctus of abdominal segment IV almost smooth, with coarse short longitudinal ribs near its anterior margin. Presclerites of abdominal segment IV reticulate-imbricate. Abdominal tergites V–VI largely smooth with superficially imbricate anterior face. Abdominal tergite VII (pygidium) coarsely areolate-reticulate except superficially imbricate anterior face, armed with numerous stout chaetae arranged in two or three irregular oblique-longitudinal rows along each posterolateral margin.
Queen
Largely similar to the worker except for some queen-specific features. Eyes and ocelli large and conspicuous; eyes circular with ~ 20 ommatidia at maximum diameter in lateral view; minimal distance between margins of median and lateral ocellus as long as major diameter of median ocellus; minimal distance between margins of lateral ocelli ~ 2× major diameter of median ocellus. Mesosoma with fully developed flight sclerites and wing basal remnants; pronotum dorsolaterally coarsely foveolate-reticulate; notauli weakly present as coarse groove; parapsidal lines distinct; mesopleuron almost smooth; oblique mesopleural sulcus deep and conspicuous. Petiole in dorsal view almost as long as wide (DPI, 100–101); abdominal segment III in dorsal view 1.15–1.19× wider than long (DA3I, 115–119); abdominal segment IV in dorsal view 1.10–1.12× longer than wide (DA4I, 89–91). Putative glandular patch near posterior edge of abdominal poststernite IV feebly recognizable as in worker.
Type Material
- Holotype. Worker; Vietnam, Dak Lak Province, Ea Kar District, Ea So Nature Reserve; 12.9676°N, 108.5230°E, 478 m alt.; 17 Sept. 2019; K. Eguchi leg.; colony code Eg17ix19-297; IEBR.
- Paratypes. 6 workers and 2 dealate queens from the same colony as the holotype; IEBR, MCZC, MHNG, MNHAH.
Etymology
The specific epithet is named after the type locality, Ea So Nature Reserve: easo combined with the Latin feminine suffix -ana, adjective.