The Neotropical myrmicine ant genus Allomerus Mayr is revised. The genus is
apparently monophyletic based on the antennal club confi guration. I recognize 8 species
(4 described as new): Allomerus brevipilosus n. sp. (Brazil), A. decemarticulatus
Mayr (Brazil, French Guiana), A. dentatus n. sp. (Venezuela), A. maietae n. sp.
(Brazil), A. octoarticulatus Mayr (=A. tuberculatus Forel n. syn. = A. octoarticulatus
var. demerarae W. M. Wheeler n. syn. = A. novemarticulatus Wheeler & Mann n.
syn. [Brazil, Bolivia, Colombia, French Guiana, Peru]), A. septemarticulatus Mayr
status rev. (Brazil), A. undecemarticulatus n. sp. (Venezuela) and A. vogeli Kempf
(Venezuela, Brazil). Better knowledge of the taxonomy of Allomerus is needed to
understand the apparently sporadic differences in antennal fl agellomere number and
speciation processes that are probably linked to plant cavity colonization.