How to use a Lucid key

This key was developed to aid in the identification of rangeland grasshoppers. Basic knowledge of grasshopper features and terminology is helpful using this key. A glossary with illustrations has been included as a reference.

Lucid Javascript key

The key consists of four adjustable panes. The left two panes relate to characters and character states (features and states) and the right two panes to the grasshopper species (entities) available in this key.

The top left pane lists the available features and their character states, which can be selected during the identification process. This listing is reduced when character states are selected. The species remaining are displayed in the pane to the top right.

The bottom left pane displays the feature states that have been selected, and the discarded entities are displayed in the pane to the bottom right.

Using the key

The key contains a list of grasshoppers, their features and associated character states. The process of identifiying a grasshopper is done by making character state selections, thus removing grasshoppers from that list that do not match the combination of character states selected. This process of selecting character states continues until the grasshopper (entities) list is reduced to a short list of possibilities, and in most cases, down to a single grasshopper.

Selecting character states

Most character states are accompanied by an illustration. Click on the illustration's thumbnail to see an enlarged version. To select a state, click in the checkbox to the left of the state text.

The identification process

Start by selecting character states in any order you wish. If you're not sure about a particular character, then try selecting a different feature that you're more confident about. You are not required to select character states in any particular order. Continue the selection process until the list of remaining taxa in the bottom right pane is reduced as much as possible. The goal is to reduce this list to a single taxa without guessing character states.

If you select the wrong character state by mistake, just remove it by unchecking.

Depending on your experience with grasshoppers, you might not be able to confidently select enough character states to reduce the list of remaining taxa to a single species. If this happens, you can use the attached fact sheets and images to continue and complete the identification process.

Things to be aware of

During the identification process, it is possible to end up with an empty list of taxa remaining for the combination of character state selected. When this happens, one of the following situations has occurred:

• It's possible that the combination of character states selected do not uniquely identify any grasshopper (taxa) available in this version of the key.
• The wrong character state was selected by accident, or picked by guessing. The resulting combination of character states do not uniquely identify any grasshoppers in this key. To overcome this, check to make sure that all the character states selected are correct, removing any character state that was selected by guessing or by mistake. Removing one or more character states will return grasshoppers back to the list of possibilities. Now use the fact sheets and associated images for this list of grasshoppers to complete the identification process.
• It is possible that the taxa you are trying to identify is available in the key, but has been scored incorrectly by the author. If after using some other means to identifiy the species in question you still feel that there a mistake with the key, please email Chris.Reuter@aphis.usda.gov and mbrust@csc.edu with the name of the species and the combination of character states that incorrectly filter out that species.

For additional tips on using Lucid keys, see these Best Practices.