This page illustrates miscellaneous taxonomically important structures of various species treated in LepIntercept. These images were created using various light microscope techniques in order to demonstrate some of the tools a port identifier might use to study Lepidoptera larvaelarva:
the stages between the egg and pupa of those insects having complete metamorphosis
. The value of other systems such as scanning (SEM) or transmitted electron microscopy (TEM), and more recently confocal microscopes, is well known. An example of the use of an SEM to illustrate caterpillarcaterpillar:
a larva with a conspicuous head, three pairs of thoracic legs, and prolegs; the larva of a butterfly, moth, sawfly, or scorpionfly (= eruciform)
morphology is found in some chapters of Stehr (1987). The use of a confocal microscope and fluorescence was discussed by Lee et al. (2009)Lee et al. (2009):
Lee, S., R. L. Brown and W. Monroe. 2009. Use of confocal laser scanning microscopy in systematics of insects with a comparison of fluorescence from different stains. Systematic Entomology 34: 10-14.. Microscopy with special reference to port identifiers was covered by Passoa (1997)Passoa (1997):
Passoa, S. 1997. Final report: video image transfer through a microscope. U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Plant Protection and Quarantine unpublished report for the Remote Pest Identification Project pilot project. 7 pp..
MacKay (1959)MacKay (1959):
MacKay, M. R. 1959. Larvae of the North American Olethreutidae (Lepidoptera). Canadian Entomologist Supplement 10: 1-338. did not illustrate the SD2 setaseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
in the codling moth or Oriental fruit moth. We illustrate the presence of this setaseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
in both species. The codling moth was done in Rheinberg illumination resulting in the SD2 shining red against the blue background. If no colored stops are used, a darkfield effect is produced. This is shown in the Oriental fruit moth. In both cases the pinaculapinaculum:
a small, flat, or slightly elevated chitinized area bearing a seta or setae
shape is more obvious. This method of coloring with filters can save time by eliminating a need to stain. Darkfield can be produced by using a special condenser or setting a phase condenser on Ph2 or Ph3 with a low power objective (typically 4x or 10x). An oil objective with iris works best at higher powers.
The cuticle texture of H. assulta, at least in middle instars, is uniformly composed of fine spines and small round granules. This differs from H. armigera that has the spinules in bands from the middle to late instars. The lower power view was done in brightfield with the condenser iris partially closed. Differential interference contrast was used to get more detail on the texture between the granules. Another example of cuticle texture is shown with phase contrast (Ph3) on an Amorbia specimen.
The mandibles of D. considerata and D. magnifactella were both done with crossed polarizers to bring out the inner tooth character more clearly. In the case of D. considerata, similar to a photographer who blurs the background to emphasize a subject, the depth of field was limited to the mandibular ridge with the tooth for clarity. In fact, an advantage of differential interference contrast over phase contrast is the shallow focus (optical sectioning) that allows dorsaldorsal:
at the top or back or above
and ventral surface to be easily distinguished. The apical setaeseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
on the spinneretspinneret:
a structure from which silk is spun, usually located on the labium of larvae
of D. considerata, and the position of the SD2 setaseta:
a hairlike projection of the body wall that is articulated in a socket; compare to spine
on A8 under the middle of the SD1 pinaculumpinaculum:
a small, flat, or slightly elevated chitinized area bearing a seta or setae
in D. magnifactella, were both done in brightfield.
