LepIntercept was produced as an identification resource for Lepidoptera larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
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 "How to Use LepIntercept" menu item on the right of this page.
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" page.
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)Zahiri et al. (2011):
Zahiri, R. I. J. Kitching, J. D. Lafontaine, M. Mutanen, L. Kaila, J. D. Holloway and N. Wahlberg. 2011. A new molecular phylogeny offers hope for a stable family level classification of the Noctuoidea (Lepidoptera). Zoologica Scripta 40: 158-173., and other publications listed directly on the individual fact sheets. Diagnostic characters listed for larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
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)Cavey (2001):
Cavey, J. 2001. Quarantine status pest categorization process. U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Plant Protection and Quarantine unpublished report. 3 pp. Central Science Laboratory. 2005. Pest risk analysis for Diaphania indica. Department for Environment, Food and Rural Affairs. 9 pp. that determines if a particular taxon is quarantine significant for the U.S.
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 larvalarva:
the stages between the egg and pupa of those insects having complete metamorphosis
actually feeds on the intercepted host. There could be a misidentification of either the host or the insect. Another possibility is that the larvalarva:
the stages between the egg and pupa of those insects having complete metamorphosis
may have been knocked off the true host in transit or the larvalarva:
the stages between the egg and pupa of those insects having complete metamorphosis
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.
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 LepInterceptIn order to examine minute structures on larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
, at least one individual from nearly every taxon was dissected and slide mounted. A slit was cut in the larvalarva:
the stages between the egg and pupa of those insects having complete metamorphosis
from the anus to the head capsule on the dorsaldorsal:
at the top or back or above
surface between the V setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
using small Vannas spring scissors (Fine Science Tools; 2mm cutting edge). The larvalarva:
the stages between the egg and pupa of those insects having complete metamorphosis
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 complexhypopharyngeal complex:
a structure consisting of the Hypopharynx, Labial palpi, and Spinneret
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 larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
is found on the Preserving and Studying Larvae page.
All photographs and figures were produced by the authors of LepIntercept (unless stated otherwise). In nearly all cases, preserved larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
were photographed because these represent the type of larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
most often encountered by identifiers, and live larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
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 larvalarva:
the stages between the egg and pupa of those insects having complete metamorphosis
in a drop of "Astroglide personal lubricant" in a petri dish, and covering the larvalarva:
the stages between the egg and pupa of those insects having complete metamorphosis
with 70% ethanol. For several close-up images, the larvalarva:
the stages between the egg and pupa of those insects having complete metamorphosis
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 scalescale:
a highly modified seta, which is somewhat expanded and usually flattened above
bars were inserted using the Photoshop Analysis tools.
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 larvalarva:
the stages between the egg and pupa of those insects having complete metamorphosis
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. Pinaculapinaculum:
a small, flat, or slightly elevated chitinized area bearing a seta or setae
size, setal length, and relative setal position were inferred from the slide mounted skin and/or detailed photographs of intact larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
.
The setal maps are designed to show the approximateapproximate:
close together
position and number of "tactile primary setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
" (see Stehr 1987: 302) for all species. We did not study the thoracic leg or anal proleg chaetotaxychaetotaxy:
the arrangement and nomenclature of setae; see setal map
or any proprioceptors (MD, MSV, MV setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
). For the primary setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
, 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 bisetosebisetose:
two setae
on several of our specimens, whereas it was illustrated as trisetosetrisetose:
three setae
by Komai (1999)Komai (1999):
Komai, F. 1999. A taxonomic review of the genus Grapholita and allied genera (Lepidoptera: Tortricidae) in the Palaearctic region. Entomologica Scandinavica Supplement 55. 226 pp. and Timm et al. (2007)Timm et al. (2007):
Timm, A. E., L. Warnich and H. Geertsema. 2007. Morphological and molecular identification of economically important Tortricidae (Lepidoptera) on tropical and subtropical fruit in South Africa. African Entomology 15: 269-286.. 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 setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
are named according to the general setal mapsetal map:
a flat, diagrammatic drawing of the arrangement of the setae on one side of a larva
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 shieldanal shield:
the dorsal shieldlike covering of the last abdominal segment (= anal plate)
.
Slide preparations of larval skins have the advantage that they can be studied under a compound microscope so that small setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
are less likely to be overlooked. However, even with a slide-mounted skin, determining the presence or position of SD2 setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
on the abdominal segments is often problematic. MacKay (1959)MacKay (1959):
MacKay, M. R. 1959. Larvae of the North American Olethreutidae (Lepidoptera). Canadian Entomologist Supplement 10: 1-338. did not show SD2 on A1-8 for either C. pomonella or G. molesta, whereas that setaseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
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 larvalarva:
the stages between the egg and pupa of those insects having complete metamorphosis
on a flat surface. MacKay (1959:11) stated that the positions of the D, SD, and L3 setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
are especially hard to represent with this method. In many cases, slide mounting the setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
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 setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
that need to be carefully examined. Noctuids may have the one prothoracic L setaseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
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 setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
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 setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
on intact specimens, remembering that setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
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.