Pacific slope form.
Atlantic slope form.
Heteroponerinae, Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia
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Identification
Specimens from the Atlantic vs. Pacific lowlands are generally distinguishable. Specimens from the Atlantic lowlands have the anterodorsal margin of the petiole relatively more angular, and the propodeal suture is relatively more impressed. However, intermediate forms can be found in some Atlantic slope localities. The typical Atlantic slope form was formerly recognized as a distinct species, Acanthoponera crassa Brown 1958. Kempf & Brown (1968) synonymized it with minor.
Range
Mexico to Ecuador. Costa Rica: occurs throughout lowland wet forest to approx. 800m.
Natural History
minor appears to be a ubiquitous inhabitant of lowland wet forest throughout Costa Rica. The species is not restricted to wet forest, because I once observed foragers to be abundant in a small pasture with scattered guava trees. The pasture was adjacent to a forest patch, so I do not know if the species requires forest as a source area. Almost the only way I ever see this species is as workers and queens scattered sparsely on low vegetation at night. At La Selva, they have been collected in dawn canopy fogging events and in Malaise traps. From these observations I conclude: (1) both workers and queens forage, (2) foraging is solitary, and (3) foraging is almost entirely nocturnal. Foragers are furtive when illuminated at night, and thus it is very difficult to follow foragers back to a nest. I observed one nest entrance at Corcovado: a small clay turret extending 1-2cm up the side of an erect plant stem.
How to collect
minor has a relatively distinctive size, color, and shape, and thus a search image can be readily formed. Once a search image is established, the species is readily captured by walking trails in lowland wet forest at night, searching low vegetation. Workers are often on leaf surfaces.
Literature Cited
Brown, W. L., Jr. 1958. Contributions toward a reclassification of the Formicidae. II. Tribe Ectatommini (Hymenoptera). Bull. Mus. Comp. Zool. 118:175-362.
Kempf, W. W., Brown, W. L., Jr. 1968. Report on some Neotropical ant studies. Papeis Avulsos Zool. 22:89-102.
Page author:
John T. Longino, The Evergreen State College, Olympia WA 98505 USA. longinoj@evergreen.edu
Date of this version: 4 September 2004.
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