How to Use LepIntercept

Larval Keys

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LepIntercept includes two types of larval keys: traditional dichotomous keys and an interactive Lucid key. The keys are designed to complement the information on the fact sheets in providing identification of Lepidoptera larvae frequently intercepted at U.S. ports of entry. Specific use of the keys is detailed below.

Dichotomous Keys

The LepIntercept Dichotomous Keys are traditional dichotomous keys, written with contrasting couplets, that are for advanced users. A PDF version of each key is provided for downloading and/or printing. Each key incorporates detailed morphological characters along with origin and host data (in most instances) to provide an identification. The level of identification may be to a particular species, species group, genus, or higher taxonomic category. Not all taxa included in the dichotomous keys are specifically treated in LepIntercept, although most are discussed in relation to other taxa that are treated. Unless specifically stated otherwise, all taxa are assumed to be late instar larvae.

The identifier is successful when he or she has navigated through a key to an ending couplet. Users of the dichotomous keys should consult the detailed information provided in the LepIntercept fact sheets (for those species treated) to verify identifications. In some instances, information in the keys is not sufficient to separate closely related species (such as H. armigera from H. zea) and DNA data or other resources may be necessary to provide or confirm identifications for many intercepted larvae.

Lucid Interactive Identification Key

The LepIntercept Interactive Identification Key is written in Lucid 3.6 and must be run from the LepIntercept website. This key is for more novice or casual users, and provides illustrations of morphological character states along with origin (and limited host) information to produce an identification. Only taxa treated in LepIntercept are included in the key, and, in most cases, the Lucid key is not designed to separate closely related taxa, but rather to point the user to the appropriate family, subfamily, or genus. In all cases, the user should consult the appropriate fact sheets for taxa remaining in the key. The key starts by forcing the user to choose the origin of the larva (or unknown if the user does not know or is uncertain - do not guess origin!). The key then prompts for the user to select the state of the prespiracular group on T1 (macro- vs. microlepidoptera), followed by other specific characters within these two general categories. Superfamily and family-specific characters are displayed once the user has navigated the preliminary categories. Taxa are scored assuming a late instar larva in all instances. Host choices under each family or superfamily represent the most common host-species combinations for a particular group - although useful, this information should be used with caution because many of species treated in LepIntercept are polyphagous and cannot be diagnosed using only host. Consult the fact sheets for a discussion of potential hosts and origins in all cases. The complete character matrix for the interactive key is available below as a PDF.

The identifier is successful when he or she has scored as many characters states as possible and one or more entities remain. In most instances, information in the key is not sufficient to separate closely related species (such as H. armigera from H. zea). The identifier should consult the fact sheets for any remaining entities (next to the species name) to determine if the description of the remaining taxa are consistent with the specimen being examined. The dichotomous keys can be used to obtain a more definitive identification if the user is comfortable with larval morphology and navigating complicated couplets. DNA data may be necessary to provide or confirm identifications for many intercepted larvae.

LepIntercept Character Matrix

 

Fact Sheets

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Detailed fact sheets for each taxon are provided under the Fact Sheets menu item. Fact sheets are arranged alphabetically by family and subfamily. Fact sheet information is organized under tabs that contain the following sections: Overview, Detailed Information, Interception Records, and Setal Map(s). Details on the information found in each of these sections is presented below. Because different web browsers result in printing inconsistencies, a printable/downloadable PDF is available at the bottom of the first page (Overview) of each fact sheet.

Overview

The Overview tab contains a quick overview of all of the information for a particular taxon. This page contains the following sections:

Taxonomy: contains information on the most current taxonomy for each taxon. The first line lists the superfamily, family, subfamily, tribe (for some taxa), genus, species, and author (for species-level taxa). English common names and synonyms are listed for many taxa. Other notes provide information about the taxonomy of a particular taxon.

Larval diagnosis (Summary): a summary of characters (usually morphological) that is used to diagnose each taxon is provided here. Nearly all morphological characters are illustrated with one or more figures. A detailed discussion of these characters is provided in the Detailed Information section.

Host/origin information: a summary of the host and origin information for each taxon from the PestID database is presented here. In many instances this information is useful in diagnosing larval specimens, especially when a particular taxon is consistently encountered on the same host/origin combination.

Recorded distribution: the recorded distribution for a particular taxon is provided here.

Identification authority (Summary): a summary of the level of identification (family, genus, species) that should be attempted for interceptions of particular taxa from a particular zoogeographic region at U.S. ports of entry. We did not compare exotic pests to possible non-targets from North America.

Pest characterization: this is the ranking of a particular taxon using the criteria outlined by Cavey (2001). Information on the taxonomy, distribution, and potential impact of each taxon is used to determine if it is quarantine significant for the U.S.

Detailed Information

The Detailed Information tab contains a detailed discussion of the larval diagnosis, identification authority, and taxonomy (for some taxa). This page contains the following sections:

Larval diagnosis (Detailed): a detailed discussion of the diagnosis for a particular taxon. Includes a review of literature descriptions and illustrations, a list of taxonomically important characters provided by different authors, and discussion of these characters in relation to the identification of larvae intercepted at U.S. ports of entry.

Identification authority (Detailed): provides detailed information on the level of identification (family, genus, species) that should be attempted for interceptions of particular taxa from a particular zoogeographic region at U.S. ports of entry. Information includes discussion of origin, host, morphological characters, and/or related species. Anything could theoretically come from anywhere; we did not assume trans-shipping for any of the identification authorities. Nor did we account for changes in foreign ports. Authorities may change and need modification as new trade patterns develop.

Taxonomy (Detailed): (for some taxa), a detailed discussion of recent taxonomic changes. Included when recent taxonomic changes might confuse users who are used to referring to a pest species in another genus.

Interception Records

A list of the interception records for a particular taxon from the PestID database are listed here:

Origin records: a list of origins that are recorded for a particular taxon.

Host records: a list of hosts for a particular taxon. Plant names are listed as exported from PestID and may be taxonomically incorrect in some instances.

Setal Map(s)

A complete setal map is provided for each taxon (with the exception of Strymon because of the absence of primary setae). Setal map illustrations were produced using Adobe Illustrator and slides of larval skins and/or detailed photographs of larval characters. A link to download a printable PDF of the setal map is provided under each illustration.

Figures

Figures in the fact sheets were photographed by the authors of LepIntercept unless otherwise stated. All figures are available in two sizes. Clicking on the small images on the right side of the page will display a much larger image in the center of the page. Large images range in size from 2400px wide to 1000px wide but are designed to scale to the size of the web browser window. Large images have a set of controls at the bottom of each image; these have the functions outlined here: Move - move the image in the browser window Enlarge (if possible) - enlarge the image to full size Close - close the image (can also simply click on the image again to close) Advance (back) - move to the previous image Play (slideshow) - display the images on the page in order Advance (forward) - move to the next image

 

System Requirements

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In LepIntercept you will find an interactive key designed to aid in the identification of Lepidoptera intercepted at U.S. ports of entry. The interactive key was developed using Lucid3 technology. Lucid3 is software for creating and using interactive identification keys, developed by Identic in Brisbane, Australia. Visit the Lucidcentral website for more information on Lucid and Lucid3.

The interactive Lucid key runs as a Lucid3 Javascript application. Use of the key (and the rest of the LepIntercept web pages) requires Internet access and a Javascript-enabled web browser such as Internet Explorer, Firefox, Chrome, or Safari. LepIntercept has been successfully tested on the following web browsers:

• Internet Explorer 9.X, 10.X, 11.X
• Firefox 23.X, 26.X, 58.X
• Chrome 31.X
• Opera 15.X

The main LepIntercept window is 960px wide and is optimized to display best on screens 1024px or wider. This resolution covers all modern computer monitors as well as many portable devices. Most tablet computers and smart phones are able to view the web pages and keys in "normal" browser mode.

NOTE: Some web pages, such as fact sheets attached to items in Lucid interactive keys, may be considered pop-ups by certain web browsers. If your browser or an add-on application is set to block pop-ups, you may not be able to view all of the content on these pages. Additionally, some web browsers or add-on applications may block "active content" on web pages or interactive keys. To take full advantage of the information presented in this Lucid tool, please consult your web browser or add-on application's help file for assistance in disabling pop-up blockers and allowing active content.

Acknowledgments

LepIntercept was developed under a cooperative agreement between the authors, Colorado State University (CSU), and the USDA-APHIS-PPQ-S&T - Identification Technology Program (ITP). Funding was provided by Section 10201 of the 2008 Farm Bill.

The authors would like to thank USDA-APHIS-PPQ-S&T - ITP, USDA-APHIS-PPQ - National Identification Services (NIS), and Colorado State University for supporting the development of LepIntercept. This work would not have been possible without the help of numerous individuals, which we attempt to list on this page. The efforts of everyone listed here are greatly appreciated, and we apologize in advance if anyone who contributed to this project was omitted.

Terrence Walters (S&T - ITP, Fort Collins) supervised the project, allowed access to ITP's Visionary Digital imaging system, and provided logistical and technical support. Joe Cavey (USDA-APHIS-PPQ - National Identification Services) provided resources needed to maintain and grow the PPQ Lepidoptera insect and book collections that directly resulted in completion of this project. Facilities at the USFS in Delaware, Ohio for S. Passoa were provided by Jim Slavicek. Facilities at USDA-S&T in Fort Collins, Colorado for T. Gilligan were provided by Richard Zink.

James Young provided extensive comments on fact sheets, keys, and consulted on numerous issues related to larval identification and identification records. He literally made sure nothing fell through the cracks and was a champion every time there was a chance to do something that benefited identifiers or this project.

The following persons and institutions provided loans or donations of larvae for morphological study: John Brown, Michael Pogue, and Alma Solis, USDA-ARS - Systematic Entomology Laboratory, Smithsonian, Washington D.C.; Estuardo Catalan, CENGICANA (Guatemalan Sugarcane Research and Training Center), Escuintla, Guatemala; Marianne Horak, Australian National Insect Collection, CSIRO, Canberra; Norman Johnson and Luciana Musetti, Charles A. Triplehorn Insect Collection, The Ohio State University; Ricardo Antonio Polanczyk, Professor Assistente Doutor em Entomologia, UNESP Jaboticabal, Brazil; Marja van der Straten, Plant Protection Service, Wageningen, Netherlands; May Berenbaum and Terry Harrison, University of Illinois; David Wagner, University of Connecticut; Thomas Giles, USDA-PPQ, Nogales; B. Christian Schmidt, Canadian National Collection of Insects, Ottawa.

Ella Gilligan (Loveland, Colorado) provided assistance with initial web page construction and tab functionality.

Michael Pogue and the following USDA-APHIS-PPQ Entomologists/Identifiers provided very helpful reviews of a beta version of this website and associated keys: Lenis Fernando, Miami, Florida; Allan Smith-Pardo, S. San Francisco, California; James Young, Baltimore, Maryland; and Stephen Young, Blaine, Washington.

Alma Solis, Michael Pogue, and John Brown (USDA-ARS-SEL) allowed access to their unpublished identification aids, keys, manuscripts, and provided taxonomic support on pyraloids, noctuoids, and tortricids, respectively.

Equipment provided by Joel Aronoff and Sue Ellis (USDA - Remote Pest Identification Program) was helpful in examining specimens used in this study. Peter Touhey (USDA - NIS) provided access to interception records in PestID. Amanda Redford (S&T - ITP) assisted with technical support for the Lucid Key. Jim Hayden (FSCA, McGuire Center) copied literature at a last minute request and assisted with pyraloid taxonomy.

George Godfrey's (Athens, Illinois) gift of his noctuid reprint collection greatly helped the reference section of this work. Equally important was Charles Triplehorn's (The Ohio State University) reprint donations from his collection. Sadly, a few of S. Passoa's undergraduate and graduate advisors who deserve thanks are not here to see this product. The late George Eickwort (Cornell University), Ellis MacLeod (University of Illinois), and Dale Habeck (University of Florida) allowed access to larval collections at their institutions. This work would have been impossible without notes taken at these collections or knowledge gained from them on morphology.

The following USDA-APHIS-PPQ Identifiers answered questions and contributed images or job aids to study and/or reference specimens that assisted greatly with this project: G. Bartman, E. Bess, J. Botz, J. Brambila, C. Brodel, J. Brusch, N. Cottrell, T. Dobbs, R. Dones, J. Dooley, J Dorshorst, R. Elliott, G. Evans, C. Gaona, P. Haslem, S.-H. Hung, R. Ito, M. Kharboutli, J. Korecki, D. Lee, L. Fernando, P. Johnson, B. Lindsey, S. Marmura, P. Marquez, N. Matteson, D. McCoy, E. McDonald, K. Metz, N. Nieves, C. O'Donnell, C. Olsen, J. Orr, R. Pingel, H. Rasmussen, S. Romero, L. Saez, M. Segall, E. Serrano, T. Skarlinsky, A. Smith-Pardo, W. Tang, R. Tracy, T. Watanabe, J. Weaver, E. White, W. Winnie, J. Young, S. Young, J. Zablotny, and J. Zhang.

Special thanks to M. Cazier Mosley, M. Kharboutli, H. Nadel, V. Mastro, and D. Lance for support of the Diatraea rearing project at the Otis Methods lab.

When the Weisman key update was submitted to a Lepidoptera-oriented journal in the 1990's by S. Passoa, it was refused with the reasoning that "if APHIS won't publish it, that is a strike against the quality of the work." If that was a strike, then it seems that Terrence Walters and the Identification Technology Program have hit a home run over the wall and out of the park with this project. We appreciate and never take this support for granted.

Materials and Methods

LepIntercept was produced as an identification resource for Lepidoptera larvae intercepted at U.S. ports of entry. Materials and methods used in the construction of LepIntercept are listed in this section. For information how to use the resources found on this site, please click on the "How to Use LepIntercept" tab at the top of this page.

 

Taxon selection

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Taxa were selected for inclusion in the project by consulting the USDA's PestID database. The top 34 most commonly intercepted Lepidoptera taxa from the past ten years (2002-2012) were selected as these make up more than 80% of the total number of larval interceptions during that time period. Spodoptera littoralis was added to complete coverage of Spodoptera, bringing the total number of taxa to 35. A complete list of the taxa treated in LepIntercept is provided on the "About LepIntercept" tab at the top of this page.

 

Fact sheets

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Information provided in the fact sheets is a combination of information pulled from the literature and personal observations. We follow the latest (2013) taxonomy for all species, and, in some cases, this taxonomy is more recent than that used in USDA publications and databases. In these cases we provide background on the taxonomic changes and cite or provide links to the appropriate literature. Tortricid taxonomy is based on the latest world catalogue at www.tortricid.net; pyraloid taxonomy is based on the world database at www.pyraloidea.org; and noctuoid taxonomy is based on Lafontaine and Schmidt (2010), Zahiri et al. (2011), and other publications listed directly on the individual fact sheets. Diagnostic characters listed for larvae are based on those listed in the literature and/or examination of preserved specimens (see material examined). In the detailed larval diagnosis we attempt to review all relevant literature for a particular taxon group and also provide a summary of our own findings. Host/origin information is a summary of the records listed in the USDA PestID database for a particular taxon. In a few cases, trade-sensitive records have been removed. Country/location and host plant names are displayed as listed in the PestID database and have not been checked for accuracy, although obvious misspellings and duplicates have been removed. The recorded distribution for each taxon was obtained from the literature in most instances. We use the term "New World" to refer to North America, Central America, South America, and the Caribbean (not including Australasia). We do not include Mexico when referring to Central America. Identification authority is provided as detailed information on the level of identification (family, genus, species) that should be attempted for interceptions of particular taxa from a particular zoogeographic region. Pest characterization is based on three factors (taxonomy, distribution, and potential impact) outlined by Cavey (2001) that determines if a particular taxon is quarantine significant for the U.S.

 

Host/origin records

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Our treatment of anomalous or doubtful host and origin records requires comment. No doubt some of these are true associations. An example is the confirmation of the codling moth on citrus using molecular diagnostics. In other cases, it is hard to imagine the larva actually feeds on the intercepted host. There could be a misidentification of either the host or the insect. Another possibility is that the larva may have been knocked off the true host in transit or the larva left the host while sitting on a table at the port awaiting inspection. Steward [1987] suggested not accepting extremely doubtful records (called conjectural data) in the PestID database and we generally agree with his policy. We call attention to those records needing confirmation and omit the less likely data.

 

Material examined

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We examined more than 200 larval specimens, most of which were preserved in ethanol. A partial list of material examined is provided here. The following collection abbreviations are used: USNM (United States National Museum/Smithsonian Institution collection, Washington, D.C.); SPIC (Steven C. Passoa collection, Columbus, Ohio); TMG (Todd M. Gilligan collection, Loveland, Colorado); MVDS (Marja van der Straten collection, Wageningen, Netherlands).

List of material examined during the development of LepIntercept

 

Larval dissections

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In order to examine minute structures on larvae, at least one individual from nearly every taxon was dissected and slide mounted. A slit was cut in the larva from the anus to the head capsule on the dorsal surface between the V setae using small Vannas spring scissors (Fine Science Tools; 2mm cutting edge). The larva was macerated in 10% KOH for approximately one hour at 60 degrees Celsius and then transferred to a petri dish filled with distilled water. Mandibles were carefully removed using small Vannas scissors and forceps, and the hypopharyngeal complex was removed by cutting a vertical slit next to each premental arm and a single horizontal slit below the prementum. The head was removed by cutting around the base of the head capsule. The larval skin was cleaned using small brushes and forceps, and all structures were slide mounted in Euparal. More information on preserving, staining, and examining larvae is found on the Larval Morphology page under the "Preserving and Studying Larvae" tab.

 

Specimen photography

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All photographs and figures were produced by the authors of LepIntercept (unless stated otherwise). In nearly all cases, preserved larvae were photographed because these represent the type of larvae most often encountered by identifiers, and live larvae may appear very different. Macro photographs were taken using a Visionary Digital BK Lab or Passport Imaging System provided by the USDA-APHIS-PPQ-S&T - Identification Technology Program (ITP). Macro photos (of any non-slide mounted subject) were produced by suspending the larva in a drop of "Astroglide personal lubricant" in a petri dish, and covering the larva with 70% ethanol. For several close-up images, the larva was pinned into the bottom of a petri dish with a foam bottom and covered with 70% ethanol. Slide photographs were taken using a Nikon DXM1200 microscope camera mounted on a Nikon Labophot microscope (or various other setups including a Nikon D90 mounted to a Martin Microscope MM adaptor on a Leitz Aristoplan or Diaplan, Nikon 80i, or Zeiss Axiomat). Nearly all figures are a stack of 3-100 individual photos produced using Zerene Stacker Professional 1.0. In Zerene Stacker, the "PMax" method was used to stack most non-slide mounted subjects, and the "DMap" method was used to stack most slide mounted subjects. All figures were edited using Adobe Photoshop CS5/6 Extended and scale bars were inserted using the Photoshop Analysis tools.

 

Illustrations and setal maps

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All illustrations for the interactive identification key and larval setal maps were produced by the authors of LepIntercept using Adobe Illustrator CS5/6. For character states figured in the identification key, actual photographs of structures were traced and/or simplified "overview" drawings of some structures were produced to illustrate a particular character. For larval setal maps, a larva was dissected (see above), the skin was slide mounted, and a photograph of the skin was imported into Adobe Illustrator to use as a template. Pinacula size, setal length, and relative setal position were inferred from the slide mounted skin and/or detailed photographs of intact larvae.

The setal maps are designed to show the approximate position and number of "tactile primary setae" (see Stehr 1987: 302) for all species. We did not study the thoracic leg or anal proleg chaetotaxy or any proprioceptors (MD, MSV, MV setae). For the primary setae, there are some differences in the setal length and relative setal position compared to the published literature. There are several possible reasons for this variation. In most cases, the drawings were produced from a single slide-mounted specimen and it is well known setal patterns can vary from individual to individual within a species or even differ on one side of the same specimen. For example, the SV group on A1 of T. leucotreta is bisetose on several of our specimens, whereas it was illustrated as trisetose by Komai (1999) and Timm et al. (2007). In addition, we did not examine the vouchers used to prepare any of the illustrations in published literature; there could be inaccuracies from the author, or even misidentifications.

Larval setae are named according to the general setal map in Stehr (1987). Naming setal groups is generally clear, but trying to decide names within setal groups (L1 or L2, SV1 or SV2, etc.) can be subject to reinterpretation among different families. This is especially true of the anal shield.

Slide preparations of larval skins have the advantage that they can be studied under a compound microscope so that small setae are less likely to be overlooked. However, even with a slide-mounted skin, determining the presence or position of SD2 setae on the abdominal segments is often problematic. MacKay (1959) did not show SD2 on A1-8 for either C. pomonella or G. molesta, whereas that seta is clearly present and easily visible in our specimens. We could not decide the condition of SD2 in our preparation of T. ni - some abdominal segments apparently lacked SD2, but it was present on other parts of the body; in the end we chose not to illustrate it. The inconspicuous SD2 in Pyrausta is present under high magnification but not shown on our map because it is basically "absent" under low power.

A major disadvantage of using a slide-mounted skin is that some inaccuracies are inherent when trying to project a cylindrical larva on a flat surface. MacKay (1959:11) stated that the positions of the D, SD, and L3 setae are especially hard to represent with this method. In many cases, slide mounting the setae distorts their shape. As a result, we did not try to illustrate differences in setal thickness. For instance, the literature discusses SD1 being hairlike or setaform on A9 in Gelechioidea and Noctuoidea (Stehr 1987) and there are other setae that need to be carefully examined. Noctuids may have the one prothoracic L seta and SD1 on T2-3 thinner than normal. Diatraea appears to have SD1 on A9 hairlike, a character not yet studied in pyraloids. Although these differences in setae may not be represented on the setal maps, they are mentioned in the fact sheet text if considered taxonomically important. In all instances, we recommend consulting the habitus photographs in the fact sheets in addition to the setal maps to determine the position, size, and shape of setae on intact specimens, remembering that setae can fall out of their socket. We do not recommend using the setal maps to "discover" new characters to distinguish close relatives in difficult groups like Diatraea or Helicoverpa.

Copyright, Contact, Citation, and Disclaimers

Copyright notice

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LepIntercept was authored under a cooperative agreement between Colorado State University (CSU) and the USDA-APHIS-PPQ-S&T - Identification Technology Program (ITP). This content may be freely distributed or copied in the public domain for non-commercial purposes. However, it is requested that in any subsequent use of this work the authors, CSU, and ITP be given appropriate acknowledgement (see below).

LepIntercept may contain information, text, and images created and/or prepared by individuals or institutions other than CSU or USDA-APHIS that may be protected by copyright. Sources of information and text are mentioned on the Acknowledgments tab, and in most instances the origin of images has been indicated on specific fact sheets. Users must seek permission from the copyright owner(s) to use this material; contact the authors (above) if you need assistance identifying or locating the copyright owner for a particular image or have any questions related to use of information on this site.

 

Contact

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LepIntercept was authored by Dr. Todd M. Gilligan and Dr. Steven C. Passoa. Todd is a Research Scientist in the Bioagricultural Sciences and Pest Management Department at Colorado State University in Fort Collins, CO. Steven is the National Lepidoptera Specialist for USDA-APHIS-PPQ and is located at The Ohio State University in Columbus, OH. Unless otherwise noted, all web pages (including design and graphics), photographs, illustrations, keys, and other documents for LepIntercept were produced by the authors. If you have any questions regarding LepIntercept, please contact Todd Gilligan [click here] for information on Tortricidae, web page content, images, or any general questions about this site. Please contact Steven Passoa [click here] for taxonomic questions on other groups, literature citations, and information on APHIS policies (identification authority, etc.).

 

Suggested citation

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Gilligan, T. M. & S. C. Passoa. 2014. LepIntercept, An identification resource for intercepted Lepidoptera larvae. Identification Technology Program (ITP), USDA-APHIS-PPQ-S&T, Fort Collins, CO. [accessed at www.lepintercept.org].

 

Image Credits

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Photo: T. M. Gilligan & S. C. Passoa, LepIntercept (www.lepintercept.org)

(Unless otherwise noted)

 

Disclaimer

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While the authors have made every effort to provide accurate information in LepIntercept, the authors, Colorado State University, and USDA-APHIS-PPQ-S&T specifically disclaim all legal liability with respect to the accuracy, completeness, or usefulness of any information contained in LepIntercept. The authors and associated institutions shall assume no legal liability for any damages, including direct, indirect, consequential, compensatory, special, punitive, or incidental damages arising from or relating to the use of LepIntercept or the information and materials provided by or linked from LepIntercept.

 

External links

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Some web pages in LepIntercept provide links to Internet sites for the convenience of users. The authors, CSU, and USDA-APHIS-PPQ-S&T are not responsible for the availability or content of these external sites, nor do the authors, CSU, and USDA-APHIS-PPQ-S&T endorse or warrant the products, services, or information described or offered by these Internet sites.