Leptogenys malama

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

Leptogenys malama casent0067685 p 1 high.jpg

Leptogenys malama casent0067685 d 1 high.jpg

Specimen Labels

This species usually forages terrestrially and workers are often found on the forest floor and in leaf litter. Workers occasionally explore lower vegetation even though their nests are consistently located in rotten logs or in soil.

Identification

A member of the attenuata species group. Rakotonirina and Fisher (2014) - Worker. Third antennal segment of normal length, less than twice the length of second segment; in full-face view, eye not breaking outline of side of head; mesopleural sulcus narrow and smooth, oriented to level of posterodorsal corner of pronotum; legs black to dark brown and tarsi light brown.

Leptogenys malama is morphologically similar to other species within the attenuata species group but can be recognized by the position of eye in the front of the head, which does not break the line of the lateral cephalic border; by the smooth and shiny mandible; and by the absence of standing hairs on the propodeal dorsum. This species can be differentiated from Leptogenys lucida, its most similar species, by its larger size and in lateral view the mesopleural sulcus running towards the posterodorsal corner of the pronotum. Within this species, three forms are observed. The first has a shallow impression on the anterior portion of petiole dorsum when viewed in profile and usually there are no standing erect hairs on the dorsum of the mesosoma and petiolar node. It has been collected from RNI Betampona, Mananara Nord, Ambatovy, and PN Mantadia. The second form has a strongly visible suture between the metapleuron and the side of the propodeum, and it has a pair of protuberances on the posterodorsal angle of the propodeum. It occurs in PN Marojejy, montane forest of Anjanaharibe and Akirindro of the Makira Reserve, and PN Masoala. The third form is recognized by its microreticulate procoxa, finely rugulose sides of mesopleuron and lower half of propodeum, sculptured suture between metapleuron and propodeum, and transversely striate propodeal declivity. It is known only from the west of Andampibe, Cap Masoala, at 125 m.

Keys including this Species

Distribution

Madagascar. The three morphotypes observed within this species occur from the PN Marojejy in the north through the PN Mantadia in the south.

Distribution based on Regional Taxon Lists

Malagasy Region: Madagascar (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Habitat

Leptogenys malama occupies the humid forests between 225 m and 1080 m in eastern Madagascar.

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

Worker

Nomenclature

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

  • malama. Leptogenys malama Rakotonirina & Fisher, 2014: 55, figs. 23A, 24B, 25A, 68, 81 (w.) MADAGASCAR.

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

Description

Worker

(12 specimens). HW: 1.08–1.41, HL: 1.48–1.84, CI: 73–78, SL: 1.40–1.80, SI: 123–133, PW: 0.85–1.11, WL: 2.29–2.90, PNH: 0.67–0.86, PNL: 0.64–0.86, PNW: 0.52–0.66, DNI: 71–85, LNI: 97–112.

Head elongate and broadest at level of eye; posterior portion of lateral margin rounding to slightly concave posterior margin; side nearly straight in front of eyes. Eye medium, greatest diameter between one-fourth and one-fifth of length of side of head; in cephalic full-face view, eye not breaking border of side of head. Antennal scape long, reaching posterior cephalic margin by one third its length. Length of third antennal segment normal, less than twice the length of the second. Mandible inner margin broadly rounded at widest portion, without blunt angle or preapical tooth. With mesosoma in profile, mesopleural sulcus narrow and not cross-ribbed, running toward level of posterodorsal corner of pronotum. Posterior margin of propodeum at level of spiracle with protruding toothlike lobe. In dorsal view, petiolar node elongate and narrowed anteriorly; in profile, node roughly as long as high; anterior margin forming a convex line with the dorsum; shallow impression usually present at junction between both faces; petiolar dorsum meets in distinct angle with straight posterior margin. Mandible smooth and shining between sparse, small punctures. Head, clypeus, mesosoma, declivitous surface, petiolar node and gaster generally smooth and shining; scattered small punctures present on head dorsum. Posterior portion of pronotal dorsum, petiolar node and first two gastral tergites usually lacking standing hairs and pubescence; dorsum of propodeum may have short, suberect hairs. Body color and basala portion of appendages black to dark brown, tarsae and apex of gaster lighter in color.

Holotype Specimen Labels

Type Material

Holotype worker: Madagascar, Toamasina, RNI Betampona, Camp Vohitsivalana, 37.1 km 338° Toamasina, -17.8867, 49.2025, 520 m, rainforest, ex rotten log, 2 Dec 2005 (B.L. Fisher et al.) collection code: BLF13310, specimen code: CASENT0067685 (California Academy of Sciences). Paratypes: 4 workers, same data as holotype but with specimen codes: CASENT0247251, CASENT0247250, CASENT0247249, CASENT0247248 (CASC, The Natural History Museum, Musee d'Histoire Naturelle Genève, Parc Botanique et Zoologique de Tsimbazaza).

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.