Leptogenys comajojo

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Leptogenys comajojo
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Genus: Leptogenys
Species group: attenuata
Species: L. comajojo
Binomial name
Leptogenys comajojo
Rakotonirina & Fisher, 2014

Leptogenys comajojo casent0132279 p 1 high.jpg

Leptogenys comajojo casent0132279 d 1 high.jpg

Specimen Labels

Colony nests have been collected from rotten logs and under the soil, and workers are known to forage through leaf litter and on lower vegetation.

Identification

A member of the attenuata species group. Rakotonirina and Fisher (2014) - Third antennal segment less than twice the length of second; eye breaking outline of side of head; mandible finely microreticulate apart from scattered piligerous punctures; median lobe of clypeus longitudinally striate; in profile, lower half of lateral surface of propodeum and each side of meso-metapleural suture finely rugose; with petiole in profile, posterodorsal angle of node not projecting posteriorly nor overhanging posterior node margin.

Distinguishing L. comajojo from similar species such as Leptogenys edsoni can be challenging, but the species is differentiated by its finely microreticulate mandible and the presence of striation on the anteromedial clypeal lobe while L. edsoni has smooth mandibles and anteromedian clypeal lobe. The roughly right posterodorsal angle of the petiolar node renders it separable from Leptogenys grandidieri and Leptogenys manongarivo, both of which have a posterodorsal angle of the petiolar node that projects posteriorly and overhangs the posterior face.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Afrotropical Region: Comoros (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Habitat

Leptogenys comajojo has a distribution restricted to the mesic forests of two islands in the Comoros, Mohéli and Mayotte. This species occupies not only natural lowland and montane rainforests, but also disturbed high montane areas.

Biology

The Leptogenys genus page has more details about the general biology of ants in this genus. The following synopsis provided by Rakotonirina and Fisher (2014) offers an overview of the Malagasy Leptogenys: Recent surveys of arthropods in the Malagasy region uncovered a wealth of new species and showed that Leptogenys is one of the dominant ponerine ants widely distributed across all types of forest habitats. Workers are usually found foraging on the forest floor or in the leaf litter and only rarely on vegetation. They nest terrestrially under the soil, rocks, logs, or rootmat ground layers and in rotten logs, branches, in rotting bamboo, and rotten tree stumps. Most of the Malagasy species are endemic to Madagascar. In all Malagasy species, winged queens are absent, which limits their ability to disperse across the complex topography and various ecological barriers in the region. In the absence of alate queens, reproduction of Leptogenys in the region may be by fission, which enhances population viscosity and may result in important morphological variation across a species' geographic range. Though queens do not fly, males of Leptogenys are alate and are one of the most frequently collected ant genera in Malaise traps throughout Madagascar. Leptogenys exhibits a wide range of phenotypic diversity segregated both among spatially isolated habitats and along continuous environmental gradients.

Castes

Male

Nomenclature

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

  • comajojo. Leptogenys comajojo Rakotonirina & Fisher, 2014: 44, figs. 29A, 62, 75 (w.) COMOROS.

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

Description

Worker

(11 specimens). HW: 0.89–0.98, HL: 1.25–1.37, CI: 70–72, SL: 1.24–1.38, SI: 138–149, PW: 0.76–0.83, WL: 2.02–2.20, PNH: 0.58–0.65, PNL: 0.53–0.57, PNW: 0.41–0.47, DNI: 76–85, LNI: 106–114. FIGURE 62. Leptogenys comajojo holotype worker CASENT0132279. A: lateral view. B: head in full-face view. C: dorsal view.

Head subrectangular and longer than broad, not strongly broadened anteriorly; sides subparallel; posterior border almost straight. Eye with maximum diameter approximately one fifth of the length of side of head; in cephalic full-face view, breaking outline of lateral margin of head. Antennal scape surpassing posterior margin of head by one fourth its length. Third antennal segment shorter than double the length of the second. Inner margin of mandible convex at apical third and with a short, blunt, preapical tooth. With mesosoma in profile, median portion of propodeal posterior border with toothlike lobe. In lateral view, petiolar node higher than long; posterior and dorsal faces meet at a right-angle. Anteromedian lobe of clypeus striate. Mandible sparsely punctulate with fine microreticulation. Dorsum of head, mesosoma and petiolar node smooth and shining apart from piligerous pits. Generally, mesopleuron and metapleuron transversely striate or finely reticulate-rugose, except for upper half of lateral propodeal surface, but at least surface immediately adjacent to meso-metapleural suture and lower half of posterior portion of mesosoma between propodeum and metapleuron covered with this sculpture. Standing hairs and pubescence present on dorsum of head and rest of body dorsum. Color black with bluish reflection or opalescence; tip of gaster and apical portion of appendages dark brown to brown.

Holotype Specimen Labels

Type Material

Holotype worker: The Comoros, Mayotte Island, Mont Combani, -12.8063, 45.1531, 370 m, rainforest, ex rotten log, 25 Nov 2007 (B.L. Fisher et al.), BLF18671, CASENT0132279 (California Academy of Sciences). Paratypes: 3 workers with same data as holotype but with specimen codes: CASENT0247285, CASENT0247286, CASENT0247287 (CASC, The Natural History Museum).

References

  • Rakotonirina, J.C. & Fisher, B.L. 2014. Revision of the Malagasy ponerine ants of the genus Leptogenys Roger (Hymenoptera: Formicidae). Zootaxa 3836, 1-163.