Strumigenys baudueri group

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Strumigenys baudueri group Bolton (2000)

Species

Afrotropical-West Palaeartic

Malesian-Oriental-East Palaeartic

Worker Diagnosis

Afrotropical-West Palaeartic

Mandibles in full-face view and at full closure triangular to elongate triangular, with serially dentate masticatory margins that engage throughout their visible length. In ventral view outer margin of mandible without a prebasal inflected angle. MI 12-20.

Dentition. A row of 7 triangular teeth follows the basal lamella, without a diastema between basal lamella and basal tooth; these 7 are followed by 4-6 minute denticles and a small apical tooth to give a total dental count of 12-14.

Basal lamella of mandible an elongate rounded lobe that is not visible or is partially visible in full-face view with the mandibles fully closed.

Labral lobes elongate-triangular to conical.

Clypeus in full-face view with sides converging anteriorly, the anterior margin narrowly or very narrowly convex, sometimes forming an anteromedian blunt point. Clypeal margin not projecting far laterally beyond the outer margins of the mandibles.

Clypeal lateral margins with small anteriorly curved simple to narrowly spatulate hairs that are decumbent to appressed, but without a freely projecting fringe of bizarre hairs; dorsum of clypeus with small, simple to spatulate hairs that are usually decumbent to appressed.

Preocular carina conspicuous in full-face view.

Ventrolateral margin of head between eye and mandible bluntly angular to rounded.

Postbuccal impression a distinct notch in profile.

Cuticle of side of head within scrobe reticulate-punctate.

Scape short to very long, SI 61-116, cylindrical to subcylindrical, the dorsum and ventre not converging anteriorly to form a flange or thin lamella at the leading edge.

Ventral surface of scape convex to shallowly concave.

Leading edge of scape without specialised projecting hairs; any hairs that are present are small, simple to narrowly spatulate, subdecumbent to appressed, and all directed toward the apex of the scape.

Pronotum with a median longitudinal carina present (Afrotropical species) or absent (Palaearctic species).

Propodeu m with a pair of triangular teeth subtended by a lamella on the declivity; differentiated propodeal lobes absent from base of declivity.

Spongiform appendages of waist strongly developed, the ventral curtain on the petiole deeper than the thickness of the peduncle in profile. Base of first gastral sternite usually without a dense pad or crest of spongiform tissue; some compacted pilosity may be present.

Pilosity. Pronotal humeral hair present, either flagellate or long-filiform and curved. Dorsolateral margins of head in full-face view with one or more pairs of projecting elongate specialised hairs, either flagellate or filiform. Standing hairs on dorsal surfaces of alitrunk, waist and first gastral tergite simple to flagellate. Ground pilosity of head usually dense, of small curved simple to narrowly spatulate hairs.

Sculpture. Dorsum of head behind clypeus reticulate-punctate. Pleurae, sides of propodeum and disc of postpetiole smooth and shining.

Malesian-Oriental-East Palaeartic

Mandibles in full-face view and at full closure triangular to elongate triangular, with serially dentate masticatory margins that engage throughout their visible length. In ventral view outer margin of mandible without a prebasal inflected angle. MI 12-20.

Dentition. A row of 7 triangular teeth follows the basal lamella, without a diastema between basal lamella and basal tooth; these 7 followed by 4-6 minute denticles and a small apical tooth to give a total dental count of 12-14.

Basal lamella of mandible an elongate rounded lobe that is not visible or is partially visible in full-face view with the mandibles fully closed.

Labral lobes elongate-triangular to conical.

Clypeus in full-face view with sides converging anteriorly, the anterior margin narrowly or very narrowly convex, sometimes forming an anteromedian blunt point. Clypeal margin not projecting far laterally beyond the outer margins of the mandibles.

Lateral margins of clypeus with small anteriorly curved simple to narrowly spatulate hairs that are decumbent to appressed, but without a freely projecting fringe of bizarre hairs; dorsum of clypeus with small, simple to spatulate hairs that are usually decumbent to appressed.

Preocular carina conspicuous in full-face view.

Ventrolateral margin of head between eye and mandible bluntly angular to rounded.

Postbuccal impression a distinct notch in profile.

Cuticle of side of head within scrobe reticulate-punctate.

Scape short to very long, SI 61-116, cylindrical to subcylindrical, the dorsum and ventre not converging anteriorly to form a flange or thin lamella that constitutes the leading edge. Ventral surface of scape convex to shallowly concave.

Leading edge of scape without specialised projecting hairs; any hairs that are present are small, simple to narrowly spoon-shaped, subdecumbent to appressed, and all directed toward the apex of the scape.

Pronotum with median longitudinal carina present (Afrotropical species) or absent (Palaearctic species).

Propodeum with a pair of triangular teeth subtended by a lamella, teeth rarely entirely incorporated into lamella; propodeal lobes absent from base of declivity.

Spongiform appendages of waist segments strongly developed, the ventral curtain on the petiole deeper than the thickness of the peduncle in profile. Base of first gastral sternite usually without a dense pad or crest of spongiform tissue; some compacted pilosity may be present.

Pilosity. Pronotal humeral hair either flagellate or long-filiform and curved. Dorsolateral margins of head in full-face view with one or more pairs of projecting elongate specialised hairs, either flagellate or filiform. Standing hairs on dorsal surfaces of alitrunk, waist and first gastral tergite simple, filiform to flagellate. Ground-pilosity of head usually dense, of small curved simple to narrowly spatulate hairs.

Sculpture. Dorsum of head behind clypeus reticulate-punctate. Pleurae, sides of propodeum and disc of postpetiole smooth and shining.

Notes

Afrotropical-West Palaeartic

The previously known Afrotropical components of this group were fully described and discussed by Bolton (1983) as the facta-group, here absorbed into the baudueri-group. The three West Palaearctic (Mediterranean) species were discussed by Brown (1953a) and form a complex of very closely related species that are only separable by details of cephalic, and particularly clypeal, pilosity. One East Palaearctic species referable to this group is also known, see under Strumigenys masukoi.

An interesting feature of the three Mediterranean species of this group, first noted by Brown (1973a), is their tendency to fuse funicular segments 2 and 3, partially to almost totally, and to fuse the resultant segment to funicular segment 4. As a result some samples of Strumigenys baudueri, Strumigenys tenuipilis and Strumigenys tenuissima appear to have only 4 antennal segments in total, though in these funicular segment 2 appears inordinately long. Because of the fusion of funicular segments 2 and 3 some appear to have a single poorly defined segment between the first funicular and the club, so that the antenna is effectively 5-segmented.

Malesian-Oriental-East Palaeartic

Only a single species referable to this group, Strumigenys masukoi, has so far been discovered in the eastern Palaearctic. Its species-group characters distinguish it from the remaining dacetine fauna of the area. P. masukoi is considerably more densely hairy than the Mediterranean members of this group.

References