Crematogaster lobata

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Crematogaster lobata
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Crematogastrini
Genus: Crematogaster
Species: C. lobata
Binomial name
Crematogaster lobata
Emery, 1895

Crematogaster lobata casent0101773 profile 1.jpg

Crematogaster lobata casent0101773 dorsal 1.jpg

Specimen labels

Synonyms

Crematogaster lobata is found throughout the dry and littoral forests of western and northern Madagascar, mostly at low elevations ranging from 0 m to 400 m. The species seems to occur in fairly low abundance. Some isolated records exist from rainforest and gallery forest up to 770 m altitude. Crematogaster lobata co-occurs often with Crematogaster dentata, Crematogaster maina, Crematogaster ramamy and Crematogaster tricolor, as well as with Crematogaster sewellii at RS Beanka. The few colony collections available indicate that this species nests arboreally in dead branches and twigs. Crematogaster lobata is attracted to fish baits during both day and night baiting studies.

Identification

A member of the Crematogaster degeeri group. Blaimer and Fisher (2013) - Crematogaster lobata is easily recognizable by its small eyes (OI < 0.21) and lack of pronotal spines. These characters are otherwise only shared with Crematogaster mafybe; from the latter C. lobata can be distinguished by the absence of a distinct median longitudinal groove on the pronotum.

Keys including this Species

Distribution

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

Castes

Known only from the worker caste.

Worker

Worker

Nomenclature

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

  • lobata. Crematogaster sevellei var. lobata Emery, 1895f: 342 (w.) MADAGASCAR. Combination in C. (Acrocoelia): Emery, 1922e: 148; in C. (Crematogaster): Bolton, 1995b: 166. Subspecies of sewellii: Forel, 1907g: 80 (footnote). Raised to species: Santschi, 1930a: 63. Senior synonym of pacifica: Blaimer & Fisher, 2013: 32.
  • pacifica. Crematogaster pacifica Santschi, 1919b: 236 (w.) MADAGASCAR. Combination in C. (Crematogaster): Wheeler, W.M. 1922a: 1023. Subspecies of lobata: Santschi, 1930a: 63. Junior synonym of lobata: Blaimer & Fisher, 2013: 32.

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

Description

Worker

Blaimer and Fisher (2013) - (n = 20) HW 0.80-1.38; HL 0.78-1.33; EL 0.15-0.23; SL 0.57-0.90; WL 0.86-1.42; SPL 0.00; PTH 0.15-0.24; PTL 0.26-0.38; PTW 0.25-0.46; PPL 0.15-0.25; PPW 0.24-0.39; LHT 0.63-1.00; CI 1.00-1.09; OI 0.16-0.21; SI 0.66-0.80; SPI 0.00; PTHI 0.50-0.68; PTWI 0.95-1.27; PPI 1.41-1.74; LBI 1.29-1.44.

Small to very large size (HW 0.80-1.38, WL 0.86-1.42); this species seems to have a polymorphic worker caste reminiscent of majors and minors. Masticatory margin of mandibles with four teeth; head shape quadrate, mostly as long as wide (CI 1.00- 1.09); posterior margin of head in full-face view laterally angular; occipital carinae usually distinct; antennal scapes short, not reaching head margin; midline of eyes situated slightly above midline of head in full-face view; eyes very small (OI 0.16-0.21), and confluent with lateral head margin in full-face view. Pronotum laterally subangular; promesonotal suture usually indistinct in small workers and mesonotum more or less forming one plane with pronotum; in large workers, mesonotum often slightly raised with respect to pronotum and a median tubercule is present; mesonotum usually with a short, distinct posterior face; mesonotum angular laterally, ending in posterolateral tubercules; metanotal groove fairly shallow; propodeal spines absent, propodeum tuberculate directly above spiracles; dorsal face of propodeum short, posterior face of propodeum gently sloping; petiole in dorsal view broadly oval and moderately concave, without dorsolateral carinate margins and posterolateral tubercules or denticles; subpetiolar process variable, but often entirely absent; postpetiole wider than long, distinctly bilobed with a narrow median impression; subpostpetiolar process absent. Head sculpture aciculate; promesonotum usually dorsally reticulate; propleuron aciculate, mesopleuron areolate, metapleuron reticulate-carinulate; dorsal face of propodeum carinulate, posterior face reticulate; dorsal face of petiole reticulate, helcium reticulate; postpetiole dorsally reticulate; lateral and ventral face of petiole and postpetiole reticulate; face usually with sparse (two to eight) erect, longer setae, and abundant, short, appressed to suberect pubescence; erect pilosity on promesonotum highly variable, often very abundant, usually including at least eight long setae; otherwise promesonotum dorsally with regular to sparse, appressed to subdecumbent pubescence; propodeum usually laterally with long, erect setae ( > six); petiole and postpetiole usually with a pair of short erect setae posterolaterally, and shorter appressed pubescence; abdominal tergites four to seven with sparse, short, erect pilosity more abundant ventrally, and regular appressed to decumbent pubescence throughout. Color light brown to dark brown, with abdominal segments four to seven usually black.

Type Material

The lectotype designation for C. pacifica of Blaimer & Fisher (2013: 32) would appear to be unnecessary as they state "Crematogaster pacifica Santschi, 1919: 236. Worker holotype (by monotypy) from MADAGASCAR (Leg. J. de Gaulle) [NHMB, examined]." A lectotype is not required if a holotype is present.

References

  • Blaimer, B.B. & Fisher, B.L. 2013. Taxonomy of the Crematogaster degeeri-species-assemblage in the Malagasy region (Hymenoptera: Formicidae). European Journal of Taxonomy 51: 1-64 (DOI 10.5852/ejt.2013.51).
  • Emery, C. 1922c. Hymenoptera. Fam. Formicidae. Subfam. Myrmicinae. [part]. Genera Insectorum 174B: 95-206 (page 148, Combination in C. (Acrocoelia))
  • Forel, A. 1895k. [Untitled. Ponera Gleadowi n. sp.]. Pp. 60-61 [pagination of separate: 292-293] in: Emery, C. Sopre alcune formiche della fauna mediterranea. Mem. R. Accad. Sci. Ist. Bologna (5)5:59-75 (page 342, worker described)
  • Forel, A. 1907i. Ameisen von Madagaskar, den Comoren und Ostafrika. Wiss. Ergeb. Reise Ostafr. 2: 75-92 (page 80, Subspecies of sewellii (footnote))
  • Santschi, F. 1930a. Description de Formicides éthiopiens nouveaux ou peu connus. V. Bull. Ann. Soc. Entomol. Belg. 70: 49-77 (page 63, raised to species)