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10b. Antenna with 9 segments; mesosoma not strongly hourglass-shaped, moderately constricted at metanotal groove; color variable, from yellow orange to red brown to black: 30
20b. Surface of head and much of mesosoma smooth and shiny; HW less than 0.48mm: mexicana
30b. Color black to red brown, usually either uniform red brown or with dark head and gaster and mottled light and dark brown mesosoma; if clearly bicolored, pubescence on sides of head very sparse and fully appressed, pilosity on hind tibia fully appressed, and OI greater than 21: 100
40b. Maxillary palpus always 5-segmented; HW of larger workers usually less than 0.65mm (the following set of species cannot be reliably distinguished with workers but can be differentiated with queens): 60
50b. Infuscation of gastral tergites more extensive, dark brown and covering 2/3 or more of tergite; nests in one species of understory Guarea in Cordillera de Tilar‡n, Costa Rica: flavoguarea
60b. Gastral tergites with variably developed infuscated band posteriorly; hind tibia with suberect or appressed pilosity: 80
70b. Head of larger workers relatively narrow, CI 87-95; southern Pacific slope: lauropacifica
80b. Hind tibia with pilosity subdecumbent to suberect: 90
90b. Side of head with projecting setae subdecumbent, very short, much shorter than length of first funicular segment; montane areas and southern Pacific lowlands: haberi and osa
100b. Color variable; clypeus not strongly bulging; mandible without diastema between teeth 4 and 5, all 5 teeth relatively evenly spaced; HW of larger workers usually less than about 0.70mm: 110
110b. Head relatively shorter, often somewhat cordate, CI 92-107; mandible usually smooth and shining; pubescence on side of head variable, from sparse and fully appressed to abundant and suberect (workers of plebecula and joycei cannot always be distinguished): 120
120b. Never bicolored (except nanitics), head and gaster dark brown, mesosoma variably mottled light and dark red brown; pubescence on side of head and hind tibia subdecumbent; eyes relatively smaller, OI 19-21; HW of larger workers often greater than 0.53mm: joycei
QUEENS (Costa Rica)
10b. Antenna with 9 segments; color variable, from yellow orange to red brown to black: 40
20b. Mandible subtriangular with differentiated basal and masticatory margin; head not strongly dorsoventrally flattened: 30
30b. Face smooth and shiny; HW less than 0.6mm: mexicana
40b. Head dark red brown to black: 90
50b. HL less than 1.2mm: 70
60b. Gaster yellow orange with narrow infuscated bands medially; non-specialist inhabitant of live stems in Cordillera de Talamanca: meganaranja
70b. Sides of head and hind tibia with subdecumbent to suberect pilosity; HL greater than 0.85mm; eye size variable, OI 27-37; ocelli larger, OcI 6-10; specialist inhabitant of understory Ocotea: 80
80b. Eyes larger, OI 33-37; HW less than 0.8mm; southern Pacific lowlands: lauropacifica
90b. HW greater than 0.7mm; specialist or generalist inhabitant of live stems: 100
100b. HL between 0.8-1.4mm; CI 79-93; OI 23-33; OW 0.04-0.10mm; mandible punctatorugose; maxillary palpus 5 or 6-segmented: 110
110b. HW less than 1.1mm, if approaching 1.1mm then head relatively elongate (CI less than 86); OI greater than 27; most of face smooth and strongly shining: 120
120b. Sides of head with short appressed to suberect pubescence, without longer erect setae (figure is of haberi, which among following species most approaches lauroatlantica in pilosity); maxillary palpus 5 or 6-segmented: 130
130b. Workers yellow orange: 140
140b. Maxillary palpus 6-segmented; CI 79-84; HL 1.18-1.23; head more sharply rectangular, sides flat and more abruptly rounding into flat rear margin: osa
The male of M. osa is unknown.
10b. Antenna with 10 segments; apodeme of penial valve rounding into dorsal margin at obtuse angle: 40
20b. Pygostyles present: 30
30b. Paramere more elongate, with parallel sides before bluntly rounded apex: zeledoni
40b. Basiparamere lobe well developed; cuspis present or absent: 60
50b. Ocelli large, width of median ocellus greater than distance between median and lateral ocellus; petiolar dorsum with conspicuous tuft of erect setae: lauropacifica
60b. Pygostyles absent or reduced to tiny unsclerotized remnants; basiparamere lobes and parameres thin or broad: 80
70b. Digitus broadening apically to paddle-shaped apex: meganaranja
80b. Digitus evenly tapered or scimitar-shaped, never forming a bulla at apex: 90
90b. Cuspis present and subrectangular, separated from inner surface of paramere, apex sometimes approaching or touching dorsal margin of digitus: 120
100b. Digitus more evenly tapered from base to apex; cuspis as above or absent; maxillary palpus 5 or 6-segmented: 110
110b. Maxillary palpus 6-segmented; cuspis absent: lauropacifica
120b. Digitus scimitar-shaped, broadening apically: 130
130b. Basiparamere lobe and paramere broad at the base, shorter; digitus tapering to a point at apex: 140
140b. Ocelli relatively small, width of median ocellus usually less than distance between median and lateral ocellus; distance between lateral ocelli less than distance from lateral ocellus to compound eye: nigrocotea
Page author:
John T. Longino, The Evergreen State College, Olympia WA 98505 USA.longinoj@evergreen.edu
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