How to use the Species Key

The interactive key is the primary tool for specimen identification. The key diagnosis four subfamilies, 20 genera and 44 species of ants, and includes 72 characters and 171 chatacter states.

The key is designed using Lucid3 software, and differs in many respects from dichotomous keys traditionally used for ant identification. The interactive key takes a little time to learn, and users are recommended to periodically review the Best Practices guidelines for new tips and strategies.

The following is a quick guide to get you started.

  1. Requirements
  2. Video tutorial
  3. Screen windows
  4. Starting characters
  5. Character selection
  6. Taxa selection


As of May 2016, this key was updated to run on Lucid's Key Server rather than as a Java applet. All you need to use the key is your browser; you no longer need to worry about having Java up to date or adjusting your security settings to run the key.

Note: Since the key now runs on the key server rather than as an applet, it looks and functions slightly differently than in the video below. However, these difference are mostly cosmetic. The information presented in the video and text below still applies. The only major difference is that you must manually select the Features Available window in order to access the Best and Prune Redundants functions.

Video tutorial

View video tutorial

Screen windows

The screen will be divided into four windows.

  • The upper left window "Characters Available" lists the identification characters and character states to choose from.
  • The upper right window "Taxa Remaining" lists the available subfamilies, genera and species.
  • The lower left window "Characters Chosen" lists which character states are currently selected.
  • The lower right window "Taxa Discarded" lists the subfamilies, genera and species which have been rejected based on the user's selection of character states.

Starting characters

The user can choose one of five characters to start with:

  • Morphology: leads to morphological characters traditionally used to identify ant species
  • Genus: allows the user to jump to the species of a particular genus by discarding all other genera
  • Subfamily: allows the user to jump to the genera and species of a subfamilyby discarding all those in other subfamilies
  • Collection method: allows the user to restrain the list of list of available taxa to those species commonly collected by one or more of the listed methods. This option is particularly useful for Pacific Island countries participating in port of entry surveillance.
  • Advanced characters: causes additional characters to appear in the key that assume prior experience with ant identification or familiarity with the key. The measurement characters that appear for head width and head length are based on very limited specimens, and therefore allow a wide range of error.

Character selection

Characters expand into two or more character states by clicking the adjacent "+" sign. Character states are selected by clicking once on the thumbnail illustration. Clicking on the thumbnail a second time will de-select the character state. The full-sized image, along with additional example photographs, are explored by clicking on the lower right corner of the thumbnail. Once a character state is selected, the thumbnail will show a thin black line bordering its edges.

Multiple states of a single character can be selected at the same time. For example, if the specimen was collected on the ground at a port, both character states can be chosen. If the antennae appears to have a club, but the user is not sure whether it is a two-segmented or three-segmented club, both character states can be chosen, and only those species with no antennal club will be discarded.

Using the "find best" feature (the magic wand icon at the top of the page) is highly recommended when multiple characters are available to choose from. The function will highlight the character that most usefully splits the remaining taxa.

Taxa selection

The identification process is complete when only a single taxon remains. Although the character selection process will not automatically end, once the list of taxa remaining is reduced to one no further selection is necessary.