Key tips

Lucid Key Best Practices

These best practices were adapted from the Lucid Player Help pages as well as from Lucid training workshops. You can access the complete Lucid Player Help pages by clicking on your key's question mark button (the right-most button in the key's menu bar).

You may be using Lucid to identify an unknown pest or taxon; in Lucid and on this page, these are called Entities. You’ll be using Lucid while looking at a specimen. Here we’ll refer to this as a “specimen.” Likewise, to perform your identification you will choose the Lucid characters or characteristics that match what you’re looking at, which in Lucid and on this page, are called features and their states.

During an identification session, Lucid allows you to choose any feature's state from the Features Available list at any time. However, "stepping" through the key in a structured and sensible way will make your task of identification more efficient. Below are recommendations for increasing your efficiency and decreasing the amount of time required for identifying an unknown specimen using a Lucid key.

Become familiar with the specimen

First, become familiar with the features of the specimen you wish to identify. If you are also familiar with the key in this tool, then you may already know many of the specimen's features. Briefly reviewing these features before you start will make it easier for you to proceed through the identification.

Note and use distinctive features

Some entities may possess particularly distinctive features and/or states. Use of these may allow the entity to be keyed out in just a few steps. At the very least, starting with any particularly distinctive or striking features your specimen may possess may quickly reduce the list of Entities Remaining.

Answer easy features first

Browse the list of Features Available and address easy features first. The principles of dichotomous keys, in which the couplets must be answered in a preset order, are very familiar to most key users who often automatically apply these principles to a matrix key. Although Lucid lists the features of a key in an initial sequence in the opening window, this does not mean that the features must be selected in that order. You can select any feature from any position in the list. (Note that in some keys, where positive dependencies are used, you may be forced to choose state(s) from specific features before others become available.)

Most Lucid keys will have a wide variety of features, ranging from obvious and simple features to features that may be minute or difficult to interpret. Always start by browsing the list of Features Available for obvious features that you can quickly answer, as opposed to getting stuck on the first one. Lucid is designed to overcome problems associated with difficult features.

It's okay to skip features

In looking through the features, you may not be sure which state of a feature to choose, or a feature or state may not be clear on your specimen. Skipping the feature entirely in such cases is always an option.

Use illustrated feature notes

As you work through the list of Features Available, you may find some features or feature states that you do not understand. If so, review any explanatory notes and/or illustrations that may be associated with the features and states. In fact, it is a good idea to check the notes and illustrations before using any feature for the first time, and to become familiar with these for all the features.

Choosing multiple states

You can always choose multiple states (more than one state of a feature) if you are uncertain which state is the correct one to choose for a particular specimen. Lucid is designed to allow you to choose as many states as you require from any one feature (if, for example, your specimen is in between two states, or exhibits two or more states). Within the program's logic, these states will be connected by an "or" link. This will cause Lucid to search for all entities with any of the states you select. As a general rule, if you are unsure which of two or more states your specimen has, then choose them all. That way, you can be sure that your target entity will remain in Entities Remaining.

Finding the best feature to address next

When you have dealt with all the obvious features, use Lucid's "Best" function (the "magic wand" icon) to suggest the remaining feature that will give you the most efficient next step. The Best algorithm will assess which of the remaining features and states available will best reduce the list of Entities Remaining. Clicking the Best button will cause the Player to move to and open the best available feature. Press the button repeatedly to navigate through the Features list, if you have difficulty addressing the first feature nominated. If the list of entities in Entities Remaining changes after choosing a feature as suggested by Best, you should click the Best button again to recalculate the best feature to address next.

Other Lucid4 Player tools

You may find other Lucid4 tools helpful while navigating feature choices, such as ShortcutsPrune Redundants, and Differences (available on the key's menu bar). Explanations about how to use these functions are available through the Lucid Player Help menu.

What if no entities remain?

This will happen sooner or later in one of your Lucid sessions. If no entities are listed in the Entities Remaining window, then it simply means that no entities in the database match the set of states you have selected. Several explanations are possible, but these are some of the most common:

  • You have made an error in one or more of states you have selected. This is the most likely error for any situation in which no taxa remain.
  • The entity may be undescribed or not included in the key. In this case Lucid cannot identify the specimen, because its features are not represented in the key's data tables.
  • The key author may have made an error when constructing the key. This is unlikely, but it can happen. If, after carefully checking all the features and states and checking that the specimen you are attempting to identify would be expected to be included in the key, then a key construction error may be present.

Whichever of the above situations is suspected, you must very carefully review your chosen features and determine which ones you are uncertain about. Try unselecting uncertain states one by one to see what effect each has. One or more entities may move back into the Entities Remaining window. In difficult cases, you may need to "play" with the key, adding or deleting states progressively to try to find the best matching entity.

What if several entities remain?

Never assume that you will always end up with just one entity remaining. Some entities in the key may be very hard to differentiate, except when using difficult or obscure features. Sometimes, after you have addressed all the features, you may have a short list of entities remaining instead of just one entity. You are still much closer to an identification than you otherwise would have been. You may then have to carefully check your specimen against associated information (descriptions, images, etc. for the remaining entities) or refer to more advanced or specialist reference sources.

In some cases, if you have a short list of entities remaining but have not addressed all the features, it may be easier to check your specimen against information associated with these remaining entities. This can sometimes be faster than trying to find a feature that will discriminate among the remaining entities. If your specimen does not look similar to any of the entities remaining, you can use the same strategy described above, of unselecting states one by one, or "playing" with the key, to find the best matching entity.

Checking the result

Once you have made a preliminary identification, check the other information (descriptions from the fact sheet or the image gallery) provided for the entity. Getting a possible name for an entity from a key is not the end of an identification. You may have made errors, or your specimen may be an entity that is not in the key. In these cases, the key may have provided you with the wrong name. The associated information will often give you a good indication as to whether the answer is correct.

Adult key instructions

The adult key is navigated by clicking in a checkbox next to the feature state. Chosen features are displayed in the bottom left pane. Choosing multiple states for a single feature functions as an "OR" statement (e.g., forewingforewing:
the anterior wing
pattern: costal spotcostal spot:
a patch of contrasting scales on the costa, usually a remnant of the postmedian or preterminal fascia
OR tornal spot; not costal spotcostal spot:
a patch of contrasting scales on the costa, usually a remnant of the postmedian or preterminal fascia
AND tornal spot). Remaining entities (taxa) are displayed in the top right pane and eliminated entities are displayed in the bottom right pane. Because this key has several dependent features, it may be helpful to reload the key if too many mistakes are made selecting features. The key can be reloaded by clicking on the "Restart" (left-most) button. 

Use the "Best" function with caution! The keys will function more efficiently if you manually select characters that you are familiar with instead of using "Best." The "Best" algorithm automatically calculates and selects the feature that would eliminate approximately half of the remaining entities. As the keys are designed with several dependencies and many characters are unique to a small group of taxa, the "Best" function automatically skips many important characters. Exclusive use of the "Best" function may not result in a successful identification. 

  1. Is the moth a tortricid?
    Choose "Yes" if the specimen being keyed is a tortricid, or choose "Unsure" if you are not certain. Choosing "Yes" will automatically skip to #3 (below), "Choose the moth's origin." Choosing "Unsure" will automatically load several family level characters. The third choice, "Skip to tortricid characters," is for advanced users only and is not recommended for the novice or first time user (this option skips all family characters as well as geographic origin).
  2. Family level characters 
    This option is only loaded if "Unsure" was selected in #1 (above). Select morphological characters here to determine if the specimen is a tortricid. Six Lepidoptera superfamilies containing taxa that may be easily confused with tortricids are included in the entity list. The next option (#3) will only appear if one or more tortricid species remain in the entity list; if one of the other superfamilies is the only remaining entity, the key is completed and additional resources for Lepidoptera identification should be consulted. 
  3. Choose the moth's origin 
    Select the geographic origin of the specimen you are trying to identify. Because surveys for target species can occur in any location, this option only restricts non-targets. If you do not know the origin or are unsure, select "Unknown." It is also possible to select "Exotic" for specimens originating from outside of the continental United States; however, this option should be used with caution as the key is not designed to identify most exotic non-targets.
  4. Choose the moth's sex 
    Select the sex of the specimen. Male tortricids have a frenulumfrenulum:
    a single spine (males) or multiple spines (females) that project anteriorly from the base of the hindwing; used to couple the hindwings to the forewings in flight by means of a retinaculum on the forewing
    consisting of a single bristle, while female tortricids have a frenulumfrenulum:
    a single spine (males) or multiple spines (females) that project anteriorly from the base of the hindwing; used to couple the hindwings to the forewings in flight by means of a retinaculum on the forewing
    consisting of two or more bristles. Choosing the appropriate sex loads gender-specific characters (such as genitalia). If the sex of the specimen cannot be determined, "unknown" may be selected; however, this option should be used with caution as it will load all characters for both sexes and could lead to incorrect character combinations (e.g., a forewing costal foldforewing costal fold:
    a flap or fold at the base of the forewing that contains specialized sex scales
    in combination with female genitalic characters). Keep in mind that, while pheromone traps primarily target male moths, females are commonly found in traps and the sex of any particular specimen should not be assumed. 
  5. Head 
    Three characters are provided for the head. The number of scale rows per antennal segment can be used to separate Tortricinae from Olethreutinae. The other two characters (labial palpilabial palpi:
    a pair of sensory appendages that project from the lower part of the head; usually covered in scales and three-segmented
    length and ocelliocelli:
    adult head - a simple insect "eye" located dorsal to the compound eye; plural of ocellus
    presence) are useful for certain Sparganothini.  
  6. Wing
    Wing patterns are the second most useful diagnostic characters in the key. When choosing forewingforewing:
    the anterior wing
    patterns, select the predominate feature for the specimen you are examining. In many cases, it may be helpful to select more than one state. Forewingforewing:
    the anterior wing
    length, the presence or absence of a costal fold (males only), and general hindwinghindwing:
    the posterior wing
    appearance can also be selected. It may be difficult or impossible to make a final determination based only on wing pattern; in most cases a combination of wing pattern and male genitalia will be required for positive identification.  
  7. Male genitalia 
    These features will load only if "male" or "unknown" was selected under #4 (above). Male genitalia are the most useful diagnostic characters in the key. Genitalia are grouped by tribal type; these types are fairly consistent and can be selected based on general appearance. The type "other" covers all other types not similar to the four tribes illustrated. Both the Archipini type and Grapholitini type are further divided into genera, which are then divided into species; the other types are divided directly into species. If the genitalia of the specimen you are attempting to key does not match any of the species listed, it may be necessary to back up a level and start again, or accept an identification at the generic or tribal level (e.g., Archips sp. or Archipini). Unfortunately, genitalia for some treated non-pest species were not available for use in the key and are thus absent from the key. However, all exotic pest species are illustrated here, thus failure to match a particular species likely means that you can rule out your specimen as a target; however, always consult the fact sheets in detail before making a final determination.
  8. Female genitalia 
    These features will only load if "female" or "unknown" was selected under #4 (above). Because female genitalia are more generalized than male genitalia (with fewer species-specific characters), general characters are listed here that can be used to retain or eliminate remaining taxa. All characters are illustrated and can be selected by clicking on the appropriate image. It is unlikely that two feature states for any single character would be selected in this section. Consult the fact sheets in detail for species-specific characters not listed here.

    General tips: When the key is used to confirm or eliminate target taxa, the identifier is successful when either the targets have all been discarded (regardless of remaining entities), or if the key is completed and only a target is left in the entities remaining. When the key is used to identify non-target taxa, the identifier is successful when all target taxa have been discarded and a single non-target is left in the entities remaining. It may be difficult to positively identify all non-targets using this key; other resources are provided in the fact sheets and on this site. The identifier should consult the fact sheets for any remaining entities (next to the species name) to determine if the description of the species is consistent with the specimen being examined. Positive target species determinations may need to be sent to an expert for verification.

Larval key instructions

The larval key is navigated by clicking in a checkbox next to the feature state. Chosen features are displayed in the bottom left pane. Choosing multiple states for color or pattern features functions as an "AND" statement (body color: green AND brown = greenish-brown). Choosing multiple states for morphological features functions as an "OR" statement (anal comb: present OR absent). Remaining entities (taxa) are displayed in the top right pane and eliminated entities are displayed in the bottom right pane. Because this key has several dependent features, it may be helpful to reload the key if too many mistakes are made selecting features. The key can be reloaded by clicking the "Restart" (left-most) button. 

Use the "Best" function with caution! The keys will function more efficiently if you manually select characters that you are familiar with instead of using "Best." The "Best" algorithm automatically calculates and selects the feature that would eliminate approximately half of the remaining entities. As the keys are designed with several dependencies and many characters are unique to a small group of taxa, the "Best" function automatically skips many important characters. Exclusive use of the "Best" function may not result in a successful identification. 

  1. Is the larva a tortricid? 
    Choose "Yes" if the specimen being keyed is a tortricid, or choose "Unsure" if you are not certain. Choosing "Yes" will automatically skip to #3 (below), "Choose the larval origin." Choosing "Unsure" will automatically load several family level characters.
  2. Family level characters 
    This option is only loaded if "Unsure" was selected in #1 (above). Select morphological characters here to determine if the specimen is a tortricid. Three Lepidoptera superfamilies containing taxa that may be commonly confused with tortricids are included in the entity list. Two general categories are also included to account for character states that do not fit with any specific entities. The next option (#3) will only appear if one or more tortricid species remains in the entity list; if one of the other superfamilies or general categories is the only remaining entity, the key is completed and additional resources for larval identification should be consulted.
  3. Choose the larval origin 
    Select the geographic origin of the specimen you are trying to identify. If you do not know the origin or are unsure, select "Unknown;" however, selecting "Unknown" may reduce your chances of a successful determination as host information will not be loaded. There are also no regular hosts associated with larvae originating from Canada.
  4. Hosts (origin) 
    This option will load if any origin other than "Canada" or "Unknown" is selected in #3 (above). Choose the particular host on which the larva was intercepted, if this information is known. Choosing a host is optional, and choices here do not affect other characters in the key. DO NOT GUESS AT A HOST IF IT UNKNOWN OR NOT LISTED. The host lists are the export products on which a particular tortricid species or group is commonly intercepted. In many cases, selecting a host will narrow the entity list to one taxon (e.g. Africa: Capsicum = Thaumatotibia leucotreta). This does not mean that the single entity is the only larva found on this combination of origin/host, but rather that it is the most likely choice. ALL ENTITIES THAT REMAIN AFTER CHOOSING A SPECIFIC HOST SHOULD BE CHECKED FOR MATCHING MORPHOLOGICAL CHARACTERS. Choosing a host option is required to display the remaining features #5-8 (below).
  5. Head 
    All of the head features listed here are instar-dependent. The general color, markings, and mandible morphology can vary between instars, and all of the feature states in this section are coded assuming a late or last instar larva.
  6. Thorax 
    The thorax includes several diagnostic structures, such as the prothoracic shieldprothoracic shield:
    a sclerotized plate on the dorsal surface of the prothorax
    and the prothoracic prespiracular pinaculumpinaculum:
    flattened sclerotized plates on a caterpillar that bear the setae
    . These features (especially the prespiracular pinaculumpinaculum:
    flattened sclerotized plates on a caterpillar that bear the setae
    shape) can be used to narrow the remaining taxa to several species groups. As with the head, markings and coloration on the legs and prothoracic shieldprothoracic shield:
    a sclerotized plate on the dorsal surface of the prothorax
    change over time, and they are coded here assuming a late instar larva.
  7. Abdomen 
    The majority of diagnostic characters are found on the abdomen, and as many features should be scored here as possible. Markings, coloration, and crochet count may change between instars, but the general chaetotaxychaetotaxy:
    the arrangement of setae (in reference to Lepidoptera larvae), often depicted on a "setal map"
    should remain fairly consistent. All taxa are scored assuming a late instar larva. 
  8. Feeding habits 
    If known, choose the feeding habits of the larva. This feature separates borers from external feeders.

General tips

The identifier is successful when the key is completed and one or more entities remain. In some cases it may be impossible to key a larva to a single entity, especially if location and/or intercepted host information is not known. The identifier should consult the fact sheets for any remaining entities (next to the species name) to determine if the description of the species is consistent with the specimen being examined. DNA data may be necessary to provide or confirm identifications for many intercepted tortricid larvae.

Pupal key instructions

The TortID pupal key treats 14 taxa (species or genera) that are commonly intercepted during quarantine surveys by the USDA at United States ports of entry or are likely to be encountered during domestic surveys. It treats both native and exotic species. Though it does not take geographic origin into place, special care should be taken to check whether the identification arrived at makes sense in the context of where the pupa was found. The current distribution of all taxa treated in this key can be found on the fact sheets. It is important to note that this key is not designed to identify all tortricid pupae; rearing of adults may be necessary to confirm the identification.