Crematogaster malala

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Crematogaster malala
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Crematogaster
Species: C. malala
Binomial name
Crematogaster malala
Blaimer, 2010

Crematogaster malala casent0127524 p 1 high.jpg

Crematogaster malala casent0127524 d 1 high.jpg

Specimen Labels

The type material was collected from dead twigs in living trees located in montane rainforest.

Identification

Crematogaster malala is characterized by a combination of the following features. The petiole has postero-lateral tubercles that each bear a single, stiff and long erect seta. The postpetiole is distinctly bilobed and broadly medially impressed and also bears a pair of dorso-posterior stiff, long erect setae. These characters, together with the erect pilosity on abdominal tergites 4–7 and the 4 mandibular teeth, are shared with Crematogaster grevei. In distinction to C. grevei however the lateral portions of the promesonotum in C. malala are not raised with respect to the median portion and are postero-lateral rounded or angular. The metanotal groove further lacks lateral carinae and the promesonotum forms a convex outline in lateral view. (Blaimer 2010)

Keys including this Species

Distribution

Madagascar. Collections of this species are rare, with a few colonies from three locations of higher elevation rainforests (>1250m) in the Ankaratra (Ankazomivady), Andringitra and Midongy massifs.

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

Biology

Next to nothing is known about the biology of this species. Fisher’s collections of C. malala workers document these ants as nesting in dead twigs (n=4) and in carton nests (n=1); queens or males of this species have not yet been discovered. A recent search for C. malalain the P.N. Andringitra at about 1800m, not far from where it had been collected before, was unsuccessful and suggests that these ants might be highly restricted in habitat and possess inconspicuous life habits. (Blaimer 2010)

Morphology

Workers from the Midongy region are darker coloured than from P.C. Ankazomivady and P.N. Andringitra localities and have a denser appressed pubescence. The mesonotum is often more prominently raised over the pronotum in the P.C. Ankazomivady and P.N. Midongy material, than in workers from the other locations. (Blaimer 2010)

Castes

Nomenclature

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

  • malala. Crematogaster malala Blaimer, 2010: 24, figs. 36, 42 (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

Measurements (n=10). HW 0.89–1.09; HL 0.80–0.99; EL 0.21–0.25; SL 0.73–0.82; WL 0.97–1.16; SPL 0.18–0.27; PTH 0.20–0.24; PTL 0.23–0.28; PTW 0.29–0.41; PPL 0.17–0.21; PPW 0.26–0.36; LHT 0.70–0.88; CI 1.05–1.17; OI 0.24–0.28; SI 0.81–0.91; SPI 0.17–0.25, PTHI 0.84–1.00, PTWI 1.18–1.64, PPI 1.43–1.72; LBI 1.23–1.39.

Small to medium species (HW 0.89–1.09, WL 0.97–1.16).

Masticatory margin of mandibles with 4 teeth; posterior margin of head laterally forming round corners; antennae with scapes reaching or just surpassing posterior margin; midline of eyes situated just above midline of head in full face view.

Promesonotum with laterally rounded shoulders; promesonotal suture weakly impressed, usually complete; outline of promesonotum convex in lateral view, sometimes broken by mesonotum which is often slightly raised over pronotum and forming a small antero-medial tubercle; mesonotum postero-laterally rounded or angular; propodeal spines medium sized (SPI 0.17–0.25), less than half the width between their bases, evenly tapering, from straight to weakly curved, and in dorsal view weakly diverging; petiole in dorsal view trapezoidal, anteriorly flared into rounded lobes, dorso-lateral margins carinate, terminating in a small postero-lateral tubercle; subpetiolar process present as a long, moderately acute antero-ventral tooth; postpetiole distinctly bilobed and broadly medially impressed.

Head sculpture reduced, usually aciculate; mesosoma with meso-and metapleuron carinulate or costulate; dorsal face of propodeum weakly costulate to reticulate; posterior face largely shiny; rest of mesosoma including legs largely aciculate; dorsal face of petiole mostly shiny; postpetiole dorsally feebly reticulate; lateral and ventral face of petiole and postpetiole coarsely rugulose-reticulate; helcium dorsally carinulate; face with 2–4 erect setae; pilosity on dorsum of mesosoma 2–4 erect humeral setae, rarely one pair of erect setae at base of mesonotal tubercules; a pair of stiff, long, erect setae present on postero-lateral tubercles of petiole; dorso-posterior erect setae also present on postpetiole; abdominal tergites 4–7 with scattered erect pilosity.

Colour light to dark brown, mesosoma usually lighter coloured than head and metasoma.

Type Material

Holotype worker. MADAGASCAR: P.C. Ankazomivady, -20.79751, 47.17910, 1782m, ex dead twig above ground, disturbed montane rainforest, B.L.Fisher et al. #20466 (CASENT0140925, specimen image on Antweb) (deposited in California Academy of Sciences).

Paratypes. 4w, P.N. Befotaka-Midongy, -23.84080, 46.95750, 1250m, ex dead twig above ground, montane rainforest, (B.L.Fisher et al. #15029: CASENT0193561 and CASENT0193562; #15041: CASENT0193559 and CASENT0193560) (deposited in Museum of Comparative Zoology, South African Museum, Musee d'Histoire Naturelle Genève, University of California, Davis).

Etymology

This species’ name is derived from the Malagasy adjective “malala”, meaning “the beloved one”, inspired by happiness about the discovery of its morphological distinctness compared to the other species in the group.

References