Strumigenys mandibularis group

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Strumigenys mandibularis group Bolton (2000)

Species

Neotropical-Nearctic

Worker Diagnosis

Apical fork of mandible with one intercalary tooth or denticle. Mandible with two conspicuous acute preapical teeth; usually both about the same length or the distal longer than the proximal; uncommonly the proximal slightly longer than the distal. Preapical dentition not usually crowded near apex. MI 40-141.

Anterior clypeal margin usually shallowly convex, more rarely transverse.

Leading edge of scape usually with all hairs curved or directed toward apex of the scape (only one species with 1-2 hairs directed toward base of scape). Scape slender to moderately broad, the subbasal curve shallow to almost obliterated; short to very long, SI 54-115.

Preocular carina in profile short, terminating before level of eye or curving down toward anterior margin of eye.

Upper scrobe margin not sharply defined behind level of eye.

Ventrolateral margin of head very weakly to very obviously concave in front of eye.

Postbuccal groove small and shallow.

Propodeum usually with teeth or spines and frequently with a lower propodeal lobe at base of declivity that may be better developed than the upper propodeal tooth or spine, the two linked by a carina or lamella. Rarely propodeum unarmed or merely with a carina or lamella extending down declivity.

Ventral surface of petiole with spongiform tissue.

Pilosity. Pronotal humeral hair simple or remiform, never flagellate. Standing hairs on head and alitrunk sparse, stout and stiff, simple to remiform. Ground-pilosity of head and alitrunk of curved spatulate hairs.

Sculpture. Head and alitrunk predominantly or entirely sharply reticulate-punctate, usually with a smooth area on mesopleuron.

Notes

The members of this group were treated, a few species at a time, in a series of papers by Brown (1953c, 1953e, 1954g, 1957a, 1958b) that resolved most of the basic taxonomic problems. Most were included in an expanded mandibularis-group by Brown (1962b) which retains much the same composition here.

Members of the group are mostly relatively large, conspicuous species; some have wide distributions and are fairly common in collections. The group has two complexes of species.

cordovensis-complex

Bulla of femoral gland located at or proximal of midlength on each leg. Mandible with MI usually in range 96-141 and ML usually greater than SL (only borgmeieri outside this range, with MI 62-66 and ML/SL about the same).

mandibularis-complex

Bulla of femoral gland located close to apex on each leg. Mandible with MI usually in range 40-65 and SL usually greater than ML (only sanctipauli outside this range, with MI 91-94 and ML > SL).

Although good morphological characters are available for all species, standard indices within the mandibularis-complex can give a fair indication of identity for several of the species. The following list is arranged in order of ascending MI and shows the corresponding CI and SI ranges.

MI CI SI
mandibularis 40 101 54
godmani 41-48 88-95 71-78
smithii 52-60 81-85 79-86
cultrigera 52-60 75-79 90-102
planeti 53-57 80-85 82-85
prospiciens 53-57 76-80 82-88
biolleyi 58-65 79-85 83-91
saliens 59-64 69-77 90-106
hemidisca 60-65 79-82 88-91
sanctipauli 91-94 74-79 108-115

References