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Polyrhachis flavicornis
| Polyrhachis flavicornis | |
|---|---|
| |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Hymenoptera |
| Family: | Formicidae |
| Subfamily: | Formicinae |
| Tribe: | Camponotini |
| Genus: | Polyrhachis |
| Subgenus: | Myrmatopa |
| Species group: | flavicornis |
| Species: | P. flavicornis |
| Binomial name | |
| Polyrhachis flavicornis Smith, F., 1857
| |
In Thailand, carton nests of P. flavicornis were found on the underside of plant leaves or between leaves in lowland evergreen forest and dry evergreen forest (Jaitrong et al., 2023).
Photo Gallery
_flavicornis_species_group_(10.11646@zootaxa.5249.4.3),_Fig._4.jpg)
_flavicornis_species_group_(10.11646@zootaxa.5249.4.3),_Fig._5.jpg)
_flavicornis_species_group_(10.11646@zootaxa.5249.4.3),_Fig._6.jpg)
Identification
Kohout (2008) - Polyrhachis fruhstorferi bears a close resemblance to Polyrhachis flavicornis, a species that is widely distributed throughout South East Asia, including Borneo. In contrast, P. fruhstorferi appears to be endemic to Sulawesi. The outline and sculpturation of the head and mesosoma is very similar in both species and they have an almost identical configuration of the petiolar spines. I believe that P. fruhstorferi could prove to be just a population of P. flavicornis, but a more detailed study of the geographic variation of the latter species will be necessary to ascertain their true relationship.
Jaitrong et al. (2023) - In Thailand, Polyrhachis flavicornis is most similar to Polyrhachis varicolor. For the worker caste, the head and mesosoma are clearly black in P. flavicornis, but reddish brown in P. varicolor. For body size, P. flavicornis (HW 0.95–1.00 mm in worker, 1.15–1.20 mm in queen, 0.60 mm in male) is on average smaller than P. varicolor (HW 1.00–1.25 mm in worker, 1.25 mm in queen, 0.65 mm in male).
Keys including this Species
Distribution
Latitudinal Distribution Pattern
Latitudinal Range: 18.5° to -2.183333°.
| North Temperate |
North Subtropical |
Tropical | South Subtropical |
South Temperate |
- Source: AntMaps; Jaitrong et al., 2023
Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Indonesia, Malaysia, Singapore (type locality).
Oriental Region: Laos, Thailand.
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. |
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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. |
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Biology
Castes
Worker
Images from AntWeb
   
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| Worker. Specimen code casent0906570. Photographer Estella Ortega, uploaded by California Academy of Sciences. | Owned by NHMUK, London, UK. |
Queen
Images from AntWeb
    
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| Syntype of Polyrhachis flavicornis. Queen (alate/dealate). Specimen code casent0901877. Photographer Ryan Perry, uploaded by California Academy of Sciences. | Owned by OUM, Oxford, UK. |
Nomenclature
The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.
- flavicornis. Polyrhachis flavicornis Smith, F. 1857a: 63 (w.q.) SINGAPORE. Combination in P. (Myrmatopa): Donisthorpe, 1932c: 446.
Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.
Description
Worker
Jaitrong, Yamane, and Noon-Anant (2023) - (10 non-types). TL 3.20–3.35, HL 1.15–1.25, HW 0.95–1.00, SL 1.45– 1.55, PW 0.75–0.80, MTL 1.35–1.45, CI 79–87, SI 150–158.
Head in full-face view distinctly longer than broad, with posterior margin evenly and roundly convex, lateral margins distinctly converging anteriad. Frontal carinae distinctly elevated, posteriorly reaching level of mid-length of eye, parallel anteriorly, divergent in middle, parallel posteriorly. Clypeus transverse, trapezoidal, its posteromedian margin straight to very shallowly emarginated; anterior margin slightly convex; anteromedian portion weakly produced, with straight anterior margin and blunt lateral angles. Mandible subtriangular, masticatory margin with 5 distinct teeth. Antennal scape long, ca. 1.37–1.40 times as long as head width including eyes; pedicel more than 2.5 times as long as broad, much longer than first flagellomere that is shortest of all flagellomeres; all flagellomeres longer than broad. Eye in full-face view convex and prominent, in full-face view breaking lateral margin of head, located posterior to mid-length on lateral face of head.
Pronotum in dorsal view much broader than long, anteriorly slightly convex, laterally roundly convex, with straight posterior margin; humerus rounded, weakly angled or produced as very small process; in profile view lateral face of pronotum with shallow furrow along its anterior margin; posteroventral corner broadly rounded. Mesonotum in dorsal view demarcated anteriorly and posteriorly by distinct furrows, much narrower than pronotum, broader than long, trapezoidal, gradually narrowed posteriad; in profile view dorsal margin almost flat but posterior portion of lateral keel of mesonotal dorsum bluntly angled; mesopleuron in profile demarcated from pronotum by deep sinuate furrow but completely fused with metapleuron. Metanotal groove short (‘narrow’) and shallow, continuing down to metathoracic spiracle that has upward-directed small round opening. Propodeum in dorsal view posteriorly as broad as mesonotum; dorsal face rectangular, broader than long, gradually merging with posterior declivity; lateral face not demarcated from metapleuron; propodeal spine short, directed upward; propodeal spiracle located on lateral margin of declivity, prominent, with oblong opening.
Petiole in dorsal view broader than long; dorsal face not clearly differentiated from anterior and posterior slopes, with a pair of long lateral spines that diverge in basal part and are parallel in apical two-thirds, intercalary denticle absent; in profile view anterior slope of node straight, much shorter than posterior slope that is roundly convex; subpetiolar process ventrally with round margin but sometimes with blunt posterior angle. Head almost entirely puncto-reticulate; area between frontal carinae with much weaker sculpture. Clypeus very densely puncto-reticulate. Mandible in basal half very densely and finely striate with scattered punctures from which setae arise; apical half with much sparser and weaker sculpture and matte or weakly shiny. Antenna densely micropunctate. Pronotum and mesonotum puncto-striate, other parts of mesosoma densely puncto-reticulate to indistinctly puncto-striate. Petiole densely puncto-reticulate; sculpture on posterior face coarser; lateral spines with finer and irregular punctation. Tibiae and tarsi of all legs micropunctate and matte; femora in apical area densely punctate but in other parts superficially and more striated sculptured and shiny; coxae superficially rugulose and shiny. Gastral tergites densely micropunctate and matte; sternites with larger punctures, weakly shiny.
Body with very sparse short appressed pubescence that is absent in some parts, with few long standing hairs; pubescence abundant on gastral tergites and sternites; few standing hairs present on outer margin and along masticatory margin of mandible, clypeus anteriorly, frontal lobe, petiolar sternite anteriorly and venter of gaster. Eye without standing hairs. Head including clypeus, mesosoma, forecoxa and petiole black; mandible, antenna, legs except for forecoxa and gaster yellowish brown to dark reddish brown; antennal scape, mid- and hindcoxae, hindtibia and gaster generally darker than other brownish portions; labial and maxillary palpi yellowish.
Queen
Jaitrong, Yamane, and Noon-Anant (2023) - (2 non-types). TL 4.30–4.35, HL 1.40–1.45, HW 1.15–1.20, SL 1.80–1.85, PW 1.15–1.20, MTL 1.75–1.80, CI 82–83, SI 154–157.
General habitus similar to the worker except for caste-specific structures. Body slightly larger with head width 1.15–1.20 mm (0.95–1.00 mm in the worker). Eye larger and more prominent; ocelli arranged in low triangle. Pronotal humerus round, without any projection. Mesoscutum in dorsal view widest at midlength, with convex lateral margins, with distinct longitudinal median shallow furrow in anterior 1/4 length of scutum, notauli absent, parapsidal line in posterior half of scutum; prescutal carina absent; mesoscutellum narrower than mesoscutum, narrowed posteriorly, with ill-defined posterior face; mesopleuron divided into upper and lower sections by groove, anterior margin of lower section with high acute keel (inconspicuous in the worker). Metanotum in dorsal view short (‘narrow’), indented, sharply demarcated from propodeum by deep furrow; metapleuron barely differentiated from mesopleuron, completely fused with propodeal side; propodeal spines short, blunt. Petiolar spines much thicker and relatively shorter than in the worker; subpetiolar process developed with ventral margin straight. Body slightly hairier than in the worker; in addition to standing hairs mentioned for the worker, queen bears standing hairs as follows: one or two around ocelli, several on mesoscutum, some on mesoscutellum, some on second to fifth gastral tergites. Body color almost identical to the worker.
Male
Jaitrong, Yamane, and Noon-Anant (2023) - (non-type). TL 4, HL 0.85, HW 0.60, SL 0.95, PW 1.30, MTL 1.55, CI 71, SI 158.
With general characteristics of Polyrhachis males (Wong and Guénard, 2020). Body with weak cuticle, often deformed in dry-mounted specimens. Head in full-face longer than broad, but if including eyes, then distinctly broader than long. Clypeus transverse, posteriorly clearly demarcated from frons with posteromedian margin shallowly emarginate medially, anteriorly broadly convex, with anterior margin entire. Mandible weakly sclerotized, spatulate, twice as long as broad with outer margin curved; masticatory margin short and edentate with apex bluntly pointed. Eye large, positioned at mid-length of lateral face of head; distance between mandibular base and anterior margin of eye (malar space) half as long as maximum diameter of eye; ocelli large, arranged in very low triangle; distance between median ocellus and lateral ocelli equal to diameter of median ocellus; distance between lateral ocelli twice as long as diameter of median ocellus. Antennal scape moderately long, as long as head width including eyes.
Mesosoma in dorsal view much broader than head including eyes. Pronotum short (‘narrow’), almost entirely concealed by inflated mesoscutum; prescutal furrow complete. Mesoscutum with faint longitudinal median line, without notauli; parapsidal line present in posterior half of scutum; scuto-scutellar sulcus prominent; mesoscutellum much narrower than mesoscutum, distinctly narrowed posteriad. Metanotum short (‘narrow’), deeply indented, clearly defined from propodeum with deep furrow. Propodeum without distinct separation of dorsum from declivity; spines absent. Petiole low and globular, in dorsal view as broad as long. Gaster rather weakly sclerotized, easily deformed after drying.
Entire body superficially and finely sculptured, weakly shiny. Short appressed hairs present over body surface but often indistinct; standing hairs confined to following parts: clypeus with pair of standing hairs along posterior margin and two to three long hairs anteriorly; mandible with some long hairs of varying length on outer surface; standing hairs on maxillary and labial palpi numerous; mesoscutum with few or no standing hairs; mesoscutellum with several standing hairs and sparse appressed hairs that are longer than standing hairs; a few standing hairs present in posterolateral area of propodeum and around propodeal spiracle; petiole with ca. 20 fine standing hairs dorsally, pair of standing hairs on its sternite ventroposteriorly, and thick golden hairs on anterior face of petiolar node. Gastral tergites generally lacking standing hairs except on apical tergites; gastral sternites with more standing hairs; coxae of all legs with sparse standing hairs. Eye bearing microscopic hairs that can be recognized under high magnification (>100x). Body brown to dark brown; mandible, legs and genitalia yellowish or light brown; maxillary and labial palpi yellowish.
Type Material
Jaitrong et al. (2023) examined one syntype worker and one syntype alate queen of Polyrhachis flavicornis from Singapore (A. R. Wallace), deposited in OXUM.
The following notes on F. Smith type specimens have been provided by Barry Bolton (details):
One worker syntype and one alate queen syntype in Oxford University Museum of Natural History. Labelled “SING. 16” (= Singapore) and with a Donisthorpe type-label.
References
- Blanchard, B.D., Nakamura, A., Cao, M., Chen, S.T., Moreau, C.S. 2020. Spine and dine: A key defensive trait promotes ecological success in spiny ants. Ecolology and Evolution 00:1–12 (doi:10.1002/ece3.6322).
- Donisthorpe, H. 1932c. On the identity of Smith's types of Formicidae (Hymenoptera) collected by Alfred Russell Wallace in the Malay Archipelago, with descriptions of two new species. Ann. Mag. Nat. Hist. 10(10): 441-476 (page 446, Combination in P. (Myrmatopa))
- Heterick, B.E. 2022. A guide to the ants of Western Australia. Part II: Distribution and biology. Records of the Western Australian Museum, supplement 86: 247-510 (doi:10.18195/issn.0313-122x.86.2022.247-510).
- Jaitrong, W., Yamane, S., Noon-Anant, N. 2023. The Thai species of the Polyrhachis (Myrmatopa) flavicornis Smith, 1857 species group, with description of a new species (Hymenoptera, Formicidae, Formicinae). Zootaxa 5249(4), 446–464 (doi:10.11646/zootaxa.5249.4.3).
- Khachonpisitsak, S., Yamane, S., Sriwichai, P., Jaitrong, W. 2020. An updated checklist of the ants of Thailand (Hymenoptera, Formicidae). ZooKeys 998, 1–182 (doi:10.3897/zookeys.998.54902).
- Kohout, R.J. 2008a. A review of the Polyrhachis ants of Sulawesi with keys and descriptions of new species (Hymenoptera: Formicidae: Formicinae). Memoirs of the Queensland Museum. 52:255-317.
- Smith, F. 1857a. Catalogue of the hymenopterous insects collected at Sarawak, Borneo; Mount Ophir, Malacca; and at Singapore, by A. R. Wallace. [part]. J. Proc. Linn. Soc. Lond. Zool. 2: 42-88 (page 63, worker, queen described)
- Yamane, S., Tanaka, H.O., Hasimoto, Y., Ohashi, M., Meleng, P., Itioka, T. 2021. A list of ants from Lambir Hills National Park and its vicinity, with their biological information: Part II. Subfamilies Leptanillinae, Proceratiinae, Amblyoponinae, Ponerinae, Dorylinae, Dolichoderinae, Ectatomminae and Formicinae. Contributions from the Biological Laboratory, Kyoto University 31, 87–157.
References based on Global Ant Biodiversity Informatics
- Jaitrong W., B. Guenard, E. P. Economo, N. Buddhakala, and S. Yamane. 2016. A checklist of known ant species of Laos (Hymenoptera: Formicidae). Asian Myrmecology 8: 1-32. DOI: 10.20362/am.008019
- Noon-anant N., S. Watanasit, S. Yamane, and D. Wiwatwitaya. 2008. Nesting habits of Polyrhachis (Myrmatopa) flavicornis (Formicidae: Formicinae) in the lowland tropical rain forest of Peninsulat Thailand. Sociobiology 51(1): 73-86.
- Pfeiffer M.; Mezger, D.; Hosoishi, S.; Bakhtiar, E. Y.; Kohout, R. J. 2011. The Formicidae of Borneo (Insecta: Hymenoptera): a preliminary species list. Asian Myrmecology 4:9-58
- Robson Simon Database Polyrhachis -05 Sept 2014