Poecilomyrma

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Poecilomyrma
Poecilomyrma senirewae
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Poecilomyrma
Mann, 1921
Type species
Poecilomyrma senirewae
Diversity
2 species
(Species Checklist)

Poecilomyrma senirewae casent0101901 profile 1.jpg

Poecilomyrma senirewae

Poecilomyrma senirewae casent0101901 dorsal 1.jpg

Specimen Label

Evolutionary Relationships



Cardiocondyla



Ocymyrmex






Nesomyrmex



Xenomyrmex





Terataner




Atopomyrmex



Cataulacus










Carebara



Diplomorium






Melissotarsus



Rhopalomastix






Calyptomyrmex



Tetramorium





Cyphoidris



Dicroaspis










Aretidris



Vollenhovia





Dacetinops



Indomyrma








Crematogaster



Meranoplus






Lophomyrmex




Adlerzia



Recurvidris






Stereomyrmex




Trichomyrmex





Eutetramorium




Royidris




Malagidris



Vitsika








Huberia



Podomyrma





Liomyrmex



Metapone













Kartidris



Mayriella





Tetheamyrma




Dacatria



Proatta









Dilobocondyla



Secostruma






Acanthomyrmex



Myrmecina





Perissomyrmex



Pristomyrmex









some Lordomyrma



Propodilobus





Lasiomyrma




[some Lordomyrma




Ancyridris



some Lordomyrma









Paratopula




Poecilomyrma




Romblonella



Rotastruma








Gauromyrmex



Vombisidris





Temnothorax




Harpagoxenus




Formicoxenus



Leptothorax













Based on Ward et al. (2014) and Blaimer et al. (2018).

Sarnat and Economo (2012) - Mann named P. senirewae and its subspecies P. myrmecodiae both from the Nadarivatu area. The type series of P. senirewae is actually a mix of both species, and Mann incorrectly believed that the black-headed specimens were minor workers and the red-headed specimens were major workers. He explains that the series was taken from, “a small colony nesting in a hollow twig of a recently felled kauri tree, and a couple of individuals found on leaves.” The type series of P. myrmecodiae was taken from a Myrmecodia ant plant. The confusion Mann experienced with these ants is quite understandable, as additional collections have only contributed to the vexing question of where species boundaries lie. Mann’s prediction that these ants might be “widely distributed though locally hard to find,” has been borne out during the recent survey. Both the geographical and morphological range of this genus was significantly expanded. Poecilomyrma is now known from all seven of the largest islands (only males known from Koro), but records remain quite rare.

Identification

Sarnat and Economo (2012) - Fiji. Head shape ovoid to rectangular. Antenna 12-segmented. Antennal club 3-segmented. Antennal scrobes absent. Anterior clypeal margin variously shaped, but never armed with three broad and blunt teeth. Sides of head lacking carinate ridge extending below eye-level from mandibular insertions to posterolateral head margin. Mandibles triangular; lacking a distinct basal tooth. Mesosoma evenly convex; lacking depression separating promesonotum from propodeum; erect hairs present. Propodeum armed with spines or teeth. Propodeal lobes longer than propodeal spines. Propodeal spines distinctly longer than diameter of propodeal spiracle. Waist 2-segmented. Petiole pedunculate; lacking large anteroventral subpetiolar process.

This sole endemic ant genus of Fiji is also one of the most beautiful ants found on the islands, with a deeply grooved and very shiny integument, reduced propodeal spines, extended and spinose propodeal lobes, a long slender petiole and often striking red and black coloration.

Distribution

Poecilomyrma is the only ant genus that is strictly endemic to the Fijian archipelago. World distribution based on political regions. View/Edit Data
Poecilomyrma Distribution.png Worlddistribution legend.jpg

Species richness

Species richness by country based on regional taxon lists (countries with darker colours are more species-rich). View Data

Poecilomyrma Species Richness.png

Biology

Castes

Morphology

Worker Morphology

 • Antennal segment count 12 • Antennal club 3 • Palp formula 5,3 • Spur formula 0, 0 • Sting present

Male Morphology

 • Antennal segment count 12 • Antennal club 0 • Palp formula 5,3 • Total dental count 5 • Spur formula 0, 0

Nomenclature

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

  • POECILOMYRMA [Myrmicinae: Formicoxenini]
    • Poecilomyrma Mann, 1921: 445. Type-species: Poecilomyrma senirewae, by original designation.

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

Sarnat and Economo (2012) - The morphological variation encountered in Poecilomyrma is very difficult to organize into any geographical or phylogenetic pattern, and even after an earnest study it is to some degree arbitrary as to whether the genus is split into seven species or lumped into one. To begin with, there are three distinct color morphs. Morphotype #1 (as exemplified by P. senirewae) is all red except for the gaster. Morphotype #2 (as exemplified by Poecilomyrma sp. FJ05) has a black gaster and head, a red mesosoma, and infuscated waist segments. Morphotype #3 is entirely black. The sculpture of the mesosoma varies substantially from uniform parallel carinae to fully reticulated rugae. The cephalic sculpture, postpetiole sculpture and length of propodeal spines and lobes all vary, as well. Size also varies conspicuously. However, the aforementioned characters do not appear to be correlated with each other in any meaningful way. For example, particular sculpture patterns do not tend to correlate with color morphotype or with size or with geography.

Despite the great variance among the series of specimens collected, the variance within any particular series is quite low. That is to say, variation among local populations is quite high while variation within local populations is quite low. Similarly highly structured populations are observed in the Fijian Cerapachys. Both of these genera, in Fiji, have wingless ergatoid queens, which may be a factor in the limited gene flow. The challenges of species delineation would be better met by molecular tools capable of penetrating deeper than this cursory study of surface sculpture and color. The males are occasionally collected by malaise trapping, and they exhibit a number of variable characters as well, especially with regard to overall size, relative eye size, and color.

References

  • Bolton, B. 1994. Identification guide to the ant genera of the world. Cambridge, Mass.: Harvard University Press, 222 pp. (page 105, Poecilomyrma in Myrmicinae, Formicoxenini)
  • Bolton, B. 1995b. A new general catalogue of the ants of the world. Cambridge, Mass.: Harvard University Press, 504 pp. (page 339, Poecilomyrma in Myrmicinae, Formicoxenini)
  • Bolton, B. 2003. Synopsis and Classification of Formicidae. Mem. Am. Entomol. Inst. 71: 370pp (page 251, Poecilomyrma in Myrmicinae, Formicoxenini)
  • Dlussky, G. M.; Fedoseeva, E. B. 1988. Origin and early stages of evolution in ants. Pp. 70-144 in: Ponomarenko, A. G. (ed.) Cretaceous biocenotic crisis and insect evolution. Moskva: Nauka, 232 pp. (page 79, Poecilomyrma in Myrmicinae, Podomyrmini)
  • Donisthorpe, H. 1943g. A list of the type-species of the genera and subgenera of the Formicidae. [part]. Ann. Mag. Nat. Hist. 11(10): 617-688 (page 684, Poecilomyrma in Myrmicinae, Myrmecinini)
  • Mann, W. M. 1921. The ants of the Fiji Islands. Bull. Mus. Comp. Zool. 64: 401-499 (page 445, Poecilomyrma as genus)
  • Sarnat, E.M. & Economo, E.P. 2012. The ants of Fiji: 384 pp. UC Publications in Entomology, University of California Press.
  • Wheeler, W. M. 1922i. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. VII. Keys to the genera and subgenera of ants. Bull. Am. Mus. Nat. Hist. 45: 631-710 (page 679, Poecilomyrma as subgenus of Leptothorax (footnote))