A Quick Guide to Using the Identification Key

About the Key Back to top

The identification key used on this website was built using Lucid 3.3. This software allows one to make identifications based on a matrix of features, which a computer uses to narrow down the list of species that match the suite of features chosen by the user. Because the order in which features are selected does not matter, these matrix-based keys are far more flexible than traditional dichotomous keys, in which one is presented with a specific sequence of choices, and follows a specific path to get to a particular species. However, the matrix-based keys also require a lot of data – the matrix for our key has more than 280,000 elements! Our goal was to make the key as user-friendly as possible, basing it on features that do not require expertise with moths. However, if you come across terms with which you are unfamiliar, you may find our Glossary helpful.

Getting Started Back to top

To use the identification key, click the Identification Key link at the top or bottom of the page. Initially, the key will take a long time to load (up to a few minutes), as your computer must access more than 1,700 images that are part of the key. At first, it may appear that nothing is happening, but then an "Opening Key" progress box will pop up while the key is loading (see below). This box will indicate that the key is finished loading before it is actually ready to use. Do not close this progress box – it will close automatically when the key is ready to use.

When the key is ready to use, it will look like this:

As you can see, the key is divided into four panels, two of which are empty at first:

  1. The upper-left panel contains the list of features used in the key.
  2. The upper-right panel contains the complete list of moth species in the key.
  3. The lower-left panel will become filled with selected features, as you begin to use the key.
  4. The lower-right panel will become filled with discarded species, as you make selections in the features list.

Under the panels are different view options. For the Features panels (left side), you can use "Trees" to view them in a nested fashion, organized by broader categories, such as all of the forewing color and pattern features arranged together. Alternatively, you can just view the features as a list, using the "Lists" view. For the Entities panels (right side), you can view the complete species list ("Trees" or "Lists" both serve this purpose), or you can view all of the available images ("Images" view), including extra images of species for which we have more than one image. The advantage of viewing the species as a list is that it also allows you to see the links to informative species accounts, indicated by the arrow in the image below. These accounts contain more information that will help you finalize the identification of your moth.

In addition to the panels, the key has a set of menu items and an icon-based toolbar. For the best use of the key, make sure that Multimedia Icons and Image Thumbnails are both checked in the View menu, as shown below:

The toolbar icons have a number of functions, many of which are very useful:

  1. Restart the key (resets it, with no features selected)
  2. Collapse a list (of features or species)
  3. Expand a list (of features or species)
  4. Find (a feature or species)
  5. Show Subsets (this function does not apply to our key)
  6. Find Best Feature (for further narrowing down the list of remaining possible species)
  7. Find Previous Best Feature
  8. Find Next Best Feature (useful when you are unable to make a selection for the ‘best’ feature)
  9. Prune Redundant Features (gets rid of features that are not useful for discriminating among the remaining species)
  10. View Shortcut Features (similar to Find Best Feature, but produces a list of features that will help quickly narrow down the list of remaining possible species)
  11. Calculate Differences (opens up a window with a list of features and, for each species, the attributes that each species has for the selected feature)
  12. Why Discarded? (opens up a window that provides information on why a particular species was discarded)
  13. Help (opens this page; for additional help, see the Lucid help menu)

Identifying a Moth Back to top

Before starting to identify a moth, you may find it helpful to expand the list of features, so that you can see all of the available features from which you can choose. To do this, click anywhere in the upper-left panel, and then click . After you have done this, the "Features Available" panel should look like this:

Scroll down to see all of the available features. Alternatively, you can just expand a part of the list, using the arrows to the left of the individual features.

In general, it is a good idea to start with the ‘easy’ features first: distribution, seasonality, size, and color. Let’s say that we found a medium-sized moth with mostly-white forewings and hindwings in Seattle, WA, during July. Here’s how we might proceed:

First, select the state (Washington) from the list. Note that making this choice causes two things to happen, as shown below: 1) the list of features (other than State/Province) collapses, and 2) a new feature (In which ecoregion in Washington?) appears. This new feature is dependent on having selected Washington (it wouldn’t make sense to choose from ecoregions in Washington if we had found our moth in Idaho).

In addition, the lower panels now have items in them, reflecting the fact that you have made selections of characters (lower left) and that some species have been eliminated, because they are not known to occur in Washington (lower right):

Click ‘expand selection’ again, to re-expand the entire list of features, as shown below:

Notice that the list of ecoregions in Washington is illustrated with a set of images, but these are tiny in this view. To see the images in a larger format, click on one of them, and it will cause a pop-up image to appear. For example, if we click on the image for Puget Lowland, we will see the following:

This allows us to see that Puget Lowland is the correct ecoregion for Seattle. To see different ecoregions, use the blue arrow keys in the upper-left corner of the pop-up window.

Next, we select the seasonality for the moth, by scrolling down in the features panel, and choosing July. After that, we will choose the approximate size of our moth (medium), and if we have a precise measurement for the moth, we can also choose a precise size, using the new feature that appeared after we entered the approximate size.

Next, choose the forewing color (white, for our moth):

Repeat this for hindwing color. Now, click in the upper-right box, and you’ll see that with a few easy features, we have reduced our list of possible species from the original 1,217 species to only 23 remaining possibilities!

We can either reduce the list further by using more features, or we can scroll through images of these remaining species, to see if we can find a good match with our moth. To view the images, click one of the small images next to a species name. This will open up a pop-up window, where we can scroll through larger versions of the images of these remaining species, as shown below, making it easier to compare with our moth:

Use the arrow keys to see multiple images of the same species (single arrows), or to see a different species (double arrows). Be sure to look at all of the images for each species, as the featured image for a species may not be the one that looks most like your moth.

Once you have found a moth species that appears to be a good match, click on the icon to the left of its name (see below) to view the descriptive species account for that species.

There, you will find much more information on the habitat of this species, the species with which it is likely to be confused, and how to distinguish it reliably from those species. Use this information to finalize your identification of this moth.

System Requirements Back to top

Windows or Mac
At least 256MB RAM
Browser that supports JavaScript and Java Applets (turn off pop-up blockers in your browser’s preferences menu).

If you are having difficulties running the key with your computer, check the Java website to determine which version of Java Runtime Environment you are using (version 1.5 or greater is recommended, but avoid 1.6.11, as it has a bug that creates problems with the Lucid Applet), and to download a new version, if necessary. Mac users may need to use either Safari or Firefox, as some versions of Internet Explorer for Mac do not support Java Runtime Environment.