The family Formicidae is a well-recognized taxon belonging to the superfamily Vespoidea of aculeate Hymenoptera, with the following diagnosis (Bolton, 2003).

  • Eusocial perennial colonies with a wingless sterile worker caste (in some inquiline taxa worker caste have been secondary lost).
  • Head of female castes (worker and queen) prognathous.
  • Infrabuccal sac present between labium and hypopharynx.
  • Antenna consists of 4–12 segments in female castes and 9–13 in the male, and geniculate between elongate basal segment (antennal segment I = scape) and the remaining segments.
  • Metapleural gland present in female castes (the glands have been secondary lost in some taxa).
  • Abdominal segment II remarkably reduced in size and recognized as a differentiated petiole.
  • Reproductives of both sexes usually macropterous, but female reproductives rarely brachypterous or sometimes apterous, and male rarely apterous
  • Wings of alate queen deciduous, shed after mating.
  • Forewing venation vespoid but cross-veins 3rs-m and 2m-cu always absent.

The following dichotomous keys to subfamilies and genera are designed for the worker caste which is the most commonly encountered and sampled by standardized protocols for ant diversity assessments. A pair of contrasting descriptions of external morphology compose a couplet, and then a series of couplet composes a key. Each description of couplets ends a number or name of taxa. The numbers indicate the next couplets which users must follow, on the other hand the names indicate the subfamilies or genera as which users can determine their specimens.

© Katsuyuki EGUCHI & BUI Tuan Viet, 2007. All rights reserved.