Lophomyrmex longicornis

Specimens have been collected from lowland rainforest leaf litter, a soil core and by fogging.

Identification
A member of the Lophomymrex bedoti group.

Rigato (1994) - Lophomymrex longicornis is a very distinct species. The more constant diagnostic characters are the high SI, the very long propodeal spines (whose length is approached only by some Lophomyrmex bedoti specimens); the shape of the petiolar node in profile and, above all, the reduced pilosity on the alitrunk. The latter feature is unique if compared with all the other species in the genus.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Indonesia, Malaysia.

Nomenclature

 *  longicornis. Lophomyrmex longicornis Rigato, 1994a: 55, figs. 11, 12 (w.) BORNEO.

Worker
Holotype worker: TL 3.1, HL 0.80, HW 0.75, CI 94, SL 0.77, SI 103, PW 0.49, AL 0.98, SpL 0.39, HTL 0.74. TI 99.

Mesonotum in profile with a faint prominence and without a posterior step. Metanotal groove very shallow in profile. Propodeal spines in profile very long, straight and acute. reaching the level of the petiole-postpetiole articulation; they are also strongly divergent in dorsal view. Petiolar node in profile quite domed, with a moderately distinct angle between its anterior and dorsal faces. Postpetiole not massive, clearly shorter than the petiole.

Clypeus weakly reticulate, sublucid except for its posteriormost median portion which is smooth and shining. Frontal triangle irregularly sculptured and sublucid. Head shining, chiefly on the frons and vertex, very superficially reticulate. Genae with tiny longitudinal rugulae. Frontal lobes with faint longitudinal rugulae only. Anterior pronotal slope distinctly reticulate and sublucid. Pronotal dorsum between the lateral margins nearly glassy smooth, with only a trace of a median longitudinal carina. Pronotal sides shining, very weakly reticulate. Mesonotum, mesopleuron and propodeum, excluding its shining declivity, reticulate and somewhat subopaque or sublucid. Petiole and postpetiole with weak reticulation and sublucid, chiefly on the nodes. Gaster shining with only very superficial reticulation.

Pilosity as usual on the head, but reduced on the alitrunk. In frontal view the pronotum lacks any erect setae arising at the border with the anterior slope near the midline. In profile mesonotum with only tiny hairs or oblique pubescence marking the prominence and the posterior step.

Colour brownish yellow, head slightly darker.

Paratype workers: TL 3-3.5, HL 0.75-0.86, HW 0.68-0.81, CI 91-99, SL 0.74-0.84, SI 100-110, PW 0.46-0.55, AL 0.91-1.07, SpL 0.34-0.42, HTL 0.69-0.80, TI 92 -103 (32 measured).

As the holotype but varying as follows:

A faint posterior mesonotal step is often visible in profile. Propodeal spines not always strongly divergent in dorsal view and in profile they may be slightly curved upward, or even downward. A more evident median longitudinal carina may be present on the pronotal dorsum.

Colour varying from brownish yellow to light brown.

Type Material


Holotype worker, East Malaysia: Sarawak, 4th Diy. G. Mulu Nat. Park, RGS Expn. Long Pala, lowland rainforest leaf litter, 6.x.1977 (B. Bolton).

Paratype workers, 19 specimens with the same data as the holotype; 6 specimens, E. Malaysia: Sarawak, 4th Diy. Sawai For. Res., 4.iii.1978, rainforest soil core (N. M. Collins); 3 specimens, E. Malaysia: Sabah, Tawau, 13.xii.1981 (J. Waage); 2 specimens. Sabah. Gn. Silam 250m 1983 (R. Leakey); 3 specimens. Brunei: Bukit Sulang nr Lamunin, BM 1982-388, 20.viiiIlO.ix.1982 T9/7. fogging (N. E. Stork) (BMNH; ; ; ).

References based on Global Ant Biodiversity Informatics

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 * CSIRO Collection
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 * Pfeiffer M.; Mezger, D.; Hosoishi, S.; Bakhtiar, E. Y.; Kohout, R. J. 2011. The Formicidae of Borneo (Insecta: Hymenoptera): a preliminary species list. Asian Myrmecology 4:9-58
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