How to use the key

This tool offers a Javascript-based interactive key built using Lucid3 software. Lucid3 is software for creating and using interactive identification keys. Lucid is developed by Identic in Brisbane, Australia. Visit the Lucidcentral website for more information on Lucid and Lucid3.

Any modern web browser can be used, such as Internet Explorer, Firefox, Chrome, or Safari. Javascript must be enabled.

An interactive matrix-key is quite different from a traditional dichotomous key. The user is recommended to consult the Best Practices on occasion to pick up new tips and tricks for using the interactive key.

Note that web pages such as fact sheets attached to entities in Lucid3 keys may be considered pop-ups by certain browsers (such as Internet Explorer) when clicked on by users. If your browser blocks these pop-ups, you should allow pop-ups for this Lucid tool in your browser's Internet settings.


Screen windows

A Lucid key has four panels.

  • The upper left window Features Available lists the identification features and feature states to choose from.
  • The upper right window Entities Remaining lists the available taxa.
  • The lower left window Features Chosen lists which feature states are currently selected.
  • The lower right window Entities Discarded lists the taxa that have been discarded based the features that have been selected.

Features available

Most of the characters used in this key involve color, shape and details of punctation of the head, pronotum and elytra and number and shape of the sclerites of the internal sac of the median lobe of the aedeagus (called aedeagus in the key). Many feature states are illustrated to assist with using them as intended. The following considerations should be made while using the key:

  • Color of of various beetle body parts is used widely in the key, however it varies greatly in specimens of the same species based on specimen condition, time and method of collection, and conditions of specimen preservation. Some specimens collected more than 50 or 100 years ago lost their color almost entirely.
  • The easiest character to use involving color is Basic color for both head and elytra. We advise to begin identification with this character.
  • In an attempt to standardize color use in the key, color of various beetle parts was matched to color standards established by Ridgway (1912). Appropiriate color samples were scanned and added as illustrations of the character states.
  • Elytral color pattern was used in the past for species identification; however, it varies in some species and some exhibit various stages of pattern reduction. We tried to illustrate as many patterns for these species as possible.
  • Shape of the sutural angle of elytra varies significantly within many species.
  • Internal sac of the aedeagus provides the ultimate characters for species identification.
  • For proper observations, the internal sac of the aedeagus needs to be completely everted from the aedeagus. It is more important to pay attention to the number and shape of the internal sac sclerites and less to their relative position, as they are attached to each other by membranes, and their position can shift slightly.


Navigating the keys

Feature and entity trees can be expanded by clicking the "+" next to the grouping feature or entity. Feature states are selected by clicking once in the checkbox next to the state name or image thumbnail. Checking a second time deselects the state. As feature states are selected, the entities that do not have those features will be moved into the Entities Discarded panel.

key screen shot

All entities and many feature states are illustrated with photographs and/or drawings. Clicking on the image thumbnail (or image icon if thumbnails are not displayed) brings up a larger size image and gives the user access to the full image gallery for the feature state or entity, if available. All entities are also linked to fact sheets for the taxon. Clicking the small grey page icon next to the entity thumbnail will open the fact sheet in a new browser window.

In the key itself, many common language terms are used to help support use of the key by inexperienced individuals. However, in order to maximize their value and validity, some specialized terminology appears in the fact sheets. A glossary with links from the fact sheets is provided to assist the user in understanding such terms. An illustrated guide to chrysomelid anatomy and terminology is also included in the glossary.

If unsure of the correct state of a given feature, it is often better to try a different feature before selecting a state you are unsure about. However, the key has been coded to accommodate common mistakes and features with states that may vary. For more hints on navigating the key, see the Best Practices page.