Simopone bakeri

Known only from a few specimens, nothing is known about the biology of .

Identification
A member of the grandidieri species group. The maxillary palps of an MCZC specimen are short and the palp formula appears to be 4 (or perhaps 5), 3. If the maxillary palp has only 4 segments then bakeri will be unique in the genus. Perhaps the most obvious identifying character of this species is the anterior margin of the clypeus, which has a conspicuous prominent tooth at its midpoint, a character not shared with any other of the extralimital species. (Bolton and Fisher 2012)

Taylor (1966) - S. bakeri is more similar, and probably more closely related to Simopone chapmani than to Simopone gressitti. It is easily distinguished from chapmani by the cephalic and ocular proportions, the structure of the anterior clypeal border, and the more abundant vestiture. These three species form an apparently morphoclinal sequence (bakeri → chapmani → gressitti) in various characters, including decrease in relative size of the eyes (i.e. OI), and increase in relative head width (i.e. CI), in the spacing of the eyes relative to their maximum diameter, and in the width of the postpetiolar dorsum relative to its length. Reduction and specialization of the pilosity also follow this sequence.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Philippines, Singapore.

Nomenclature

 * . Simopone bakeri Menozzi, 1926e: 92 (w.) SINGAPORE.
 * Type-material: holotype worker.
 * Type-locality: Singapore: (C.F. Baker).
 * Type-depository: IEUB.
 * [Note: Bolton & Fisher, 2012: 71, record that a single queen in MCZC appears to have been collected with the holotype, but not mentioned by Menozzi.]
 * Status as species: Chapman & Capco, 1951: 25; Taylor, 1966b: 288 (redescription); Brown, 1975: 35; Radchenko, 1993b: 47 (in key); Bolton, 1995b: 383; Bolton & Fisher, 2012: 71; Chen, Zhou & Liang, 2015: 9 (in key); Chen, Chen & Zhou, 2019: 28 (in key).
 * Distribution: Singapore.

Worker
Taylor (1966) - The notes below are based on the unique holotype, which has the following dimensions (in mm, see preceding description for explanation of symbols): TL ca. 5.6; HL 1.00; HW 0.65; CI 65; maximum eye diameter 0.32; or 49; minimum interocular distance 0.32 (equal to eye diameter); PW 0.58; WL 1.36; petiolar node length at midline 0.72; maximum petiolar node width 0.62; postpetiolar length at midline 0.73; maximum width of postpetiole 0.65. Close to chapmani and gressitti, and agreeing with the original description of the latter, except in the following characters:

1. Smaller size (about as in chapmani), with much narrower head and proportionately much larger eyes, which are less widely separated relative to their maximum diameter; postpetiole distinctly longer than broad in dorsal view (length 1.12 X width).

2. Anterior clypeal border strongly biconcave in frontal view, with a distinct median anterior tooth.

3. Transverse occipital and anterior petiolar carinae as in chapmani.

4. Lateral mesosomal suturation weaker, as in chapmani. Dorsal promesonotal suture distinctly transversely ribbed; mesometanotal suture lacking on mesosomal dorsum.

5. Sides of postpetiole as in chapmani, almost parallel in dorsal view.

6. Sculpturation generally as in chapmani, but scaly microsculpture lacking on sides of pronotum, which are smooth and shining.

7. Vestiture much more abundant than in either gressitti or chapmani. Moderately long reelinate to sub-erect hairs fairly abundant on head, those at center of frons shortest and least abundant, those along frontal carinae more erect, a single more elongate hair above each eye. Dorsa of mesosoma, petiole and postpetiole with similar, but somewhat longer pilosity, least abundant on disc of pronotum, best developed on propodeum and petiole. Single longer hairs on pronotal humeri, on petiole slightly behind its anterior corners, and dorsa-laterally at about mid-length of postpetiole. Anterior gastric pilosity slightly less abundant and shorter than that of nodes, several more elongate hairs laterally, apex surrounded by long arched hairs. The subpetiolar process is partly obscured by glue; it appears that about 10-12 long hairs normally break its ventral profile; they do not form a regular brush-like series as in gressitti.

Type Material
Bolton and Fisher (2013) - Holotype worker, SINGAPORE (C.F. Baker) (IEUB) [not seen]. Taylor (1965) provides some extra notes on the holotype of bakeri. There is a single damaged dealate queen in MCZ (abdominal segments AIII to apex missing) which has the data “Singapore, coll. Baker”. It matches adequately the original worker description of bakeri and most of the comments by Taylor (1965). It may well have been collected by Baker along with the holotype, but it was obviously not seen by Menozzi, who does not mention it.

References based on Global Ant Biodiversity Informatics

 * Bolton B., and B. L. Fisher. 2012. Taxonomy of the cerapachyine ant genera Simopone Forel, Vicinopone gen. n. and Tanipone gen. n. (Hymenoptera: Formicidae). Zootaxa 3283: 1-101.
 * Chen Z., Y. Chen Y, and S. Zhou. 2019. Simopone fisheri sp. n., a new species of Dorylinae ants (Hymenoptera, Formicidae) from China, with an illustrated key to the S. grandidieri-group species. ZooKeys 838: 21–33.
 * Taylor R. W. 1966. Notes on the Indo-Australian ants of genus Simopone Forel (Hymenoptera-Formicidae). Psyche (Cambridge) 72: 287-290.