Tag Archive for illustrations

New line drawings for undescribed Fijian Pristomyrmex

Here are a few line drawings I am working on for the description of an undescribed species of Fijian Pristomyrmex. In the Ants of Fiji monograph, this species is listed as Pristomyrmex sp. FJ02.

Full face view of Pristomyrmex sp. FJ02. Line drawings can allow for better representation of important taxonomic features compared to specimen photographs. For example, the mandibular tooth structure is essential for Pristomyrmex species identification. The mandibular teeth on the specimen photograph used as a template for this illustration were obscured and difficult to see. The line drawing shows them quite clearly.

Rendering the characteristic foveae (circular depressions) of Pristomyrmex was a bit challenging, and I am sure my method could use some improvement. I began by using the Ellipse Tool to get the basic shapes, and then rotated them according to the template specimen. Next I used the eraser tool to break the foveae that appeared somewhat shallow. I then selected all the ‘broken’ foveae and applied a stroke profile that tapers strongly on both ends. For the ‘unbroken’ foveae I selected each individually and used the Width Tool to constrict the ellipses at a single point.

Profile of Pristomyrmex sp. FJ02. Of the over 50 known species of Pristomyrmex, this is only the second that lacks propodeal spines. The other, P. inermis, occurs in New Guinea.

I also used a new technique for the hairs on this illustration. I decided to use the Outline Stroke function for all of the hairs, and selected a white outline stroke. This allows for a white break where hairs overlap the ant profile and other strokes.

Video tutorial for tracing specimen images in Adobe Illustrator

Here is a four part video tutorial I’ve made explaining how to trace specimen photographs using Adobe Illustrator CS5 for producing high quality, scaleable line drawings. This procedure is basically the same as the one described in a previous post on illustrating ant heads. Here I trace the profile of Nylanderia bourbonica. Enjoy, and please leave a comment if you have any questions or suggestions for improvements!

Part 1 of 4. Importing the specimen image and tracing the mesosoma.

Part 2 of 4. Tracing the head.

Part 3 of 4. Tracing the waist and gaster.

Part 4 of 4. Tracing the hairs and adjusting their width profiles.

Introduced Nylanderia of the United States

I’ve spent the last couple of days parsing the differences among the many introduced species of Nylanderia. I still haven’t gotten a good look at the Rasperry Crazy Ant or Caribbean Crazy Ant or the Hairy Crazy Ant or whatever folks are calling the species that has been spreading across the southeastern United States, but apparently it is close to N. fulva and N. pubens. Hopefully John LaPolla’s revision of the Nearctic Nylanderia will be out soon, and I’ll be able to update my provincial key characters.

In the meantime, here’s a link to an illustrated comparison chart of Nylanderia introduced to the United States (including Hawaii).

And here’s a gallery of the various illustrations I’ve put together thus far for the key.

Selected references and resources of introduced Nylanderia species. (Note that all these species of Nylanderia were treated as Paratrechina prior to LaPolla et al. (2010)).

Trager, J.C. (1984) A revision of the genus Paratrechina (Hymenoptera: Formicidae) of the continental United States. Sociobiology, 9, 49-162. [Includes keys and descriptions of N. bourbonica, N. flavipes, N. guatemalensis, N. fulva, N. vividula all in addition to the native species].

LaPolla, J. S.; Hawkes, P. G.; Fisher, B. L. 2011. Monograph of Nylanderia (Hymenoptera: Formicidae) of the World, Part I: Nylanderia in the Afrotropics. Zootaxa 3110:10-36. [PDF] [Covers three spp. of Nylanderia purportedly introduced to the Afrotropics, including N. bourbonica, N. vaga and N. vividula.]

LaPolla, J.S., Brady, S.G. & Shattuck, S.O. (2010) Phylogeny and taxonomy of the Prenolepis genus-group of ants (Hymenoptera: Formicidae). Syst. Entomol., 35, 118-131. [PDF]

Ivanov, K. & Milligan, J. (2006) Paratrechina flavipes (Smith) (Hymenoptera: Formicidae), a new exotic ant for Ohio. Proc. Entomol. Soc. Washington, 110, 439-444. [Nice small paper on N. flavipes and how to distinguish it from N. vividula.]

Ants of the Southeastern United States – key to species of Nylanderia. [Excellent website of Joe MacGown with a key adapted from Trager (1984).]

Illustrating ant heads

Two symmetric sides of head are moved and joined to become one full head.

Here’s a brief tutorial on my technique for tracing ants heads from specimen photographs using Adobe Illustrator (AI) CS5. If you aren’t very familiar with AI, the best thing you can do  is to read the AI help chapters on Drawing, Layers, and Selecting and Arranging objects. The bread and butter of AI is the pen tool, so make sure to read everything having to do with it. The pen tool is not particularly intuitive, and following whatever examples the help tutorials give will get you comfortable with paths and anchor points before diving into your first illustration. Also, mastering a few of the more common keyboard shorts for hand tool, pen tool, select, direct select, arrange, convert anchor points, etc. will save plenty of time in the long run. I’ll put shortcuts in parentheses throughout this post.

Step 1. Open the specimen photograph you plan to trace in AI. This will serve as your drawing template. Double click on the layer with the photo in the Layer Panel, and name the layer something like ‘Photo’ or ‘Specimen image’. Before closing the dialog box, also click the ‘Dim Images to’ box and put a number in between 80%-70%. Also, make sure you click the ‘Lock’ layer box. CS5 also has an option for selecting ‘Template’, which is a good idea, but not essential. When selecting your template image, look for ones with all the parts you plan to illustrate clearly showing (at least on one side of the face). For example, choose one with the full antennae showing (or at least all of one scape). Also, try for images that are positioned correctly. For example, notice on the Camponotus planatus specimen image I’m using, the right eye breaks the head outline while the left eye does not. Ideally, that discrepancy wouldn’t exist. Also, notice that the scapes block both the eyes. That’s one reason I like moving the antennal scapes down when I image my own specimens.

Specimen image of Camponotus planatus imported as a template layer into Adobe Illustrator


Step 2. Make a vertical guideline running down the middle of the face. To do this make sure the rulers are showing, then click and drag on the y-axis ruler to bring a guide out to where you need it. You can unlock the guide if you need to move it. If your specimen image is not perfectly level, unlock the photo template and rotate (r) the image until it is level, then lock it again.

Guideline running down the middle of the head.

Step 3. Create a new layer and call it something like ‘Face’.

Step 4. Draw the outline of one half of the face. For some reason, I always do the right side, perhaps because it is not obscured by the paper point. The drawing is all done using the pen tool (p). I like to draw with a 1 point stroke with rounded ends (both of which options are available in the Stroke Panel).

Start at the mid-point top at the top of the head. Drop an anchor point while holding Shift to keep the handles perpendicular to the guide, and drag the anchors out a bit towards the sides of the head. This technique keeps a nice natural curve across the head when the two halves are joined later.

Now drop your anchor point, remembering to draw out the anchor handles each time.  Drop as few anchor points as possible to make the most natural and smooth lines. You can adjust the curves as you go by using the direct select tool (a) and the convert anchor points tool (Shift+c). To continue your line, hover over the anchor point with your pen tool until you see the ‘/’ symbol, then click on it (or click and hold to draw out anchor handles).


Drawing the first curve.


Continue tracing along the outside of the face. If the eyes break the outline of the head, I just ignore them. I don’t include the mandibles until later in the process, preferring instead to follow the anterior margin of the clypeus until I hit the vertical guideline.


Step 5. Next I like to do the eyes. I use the Ellipse tool (L) while holding the Control button (to expand the ellipse from the midpoint) for the first rough approximation. Then I select the four anchor points with the direct select tool (A) and move them into place and make whatever other minor adjustments with anchor handles as necessary. Once I’m satisfied with the shape, I fill it with a gradient, then use the Gradient tool to approximate a 45 degree angle.


Drawing the eye using the Ellipse tool and Gradient tools.


Step 6. Next I draw whatever interior characters seem appropriate. In this case I do the median and lateral potions of the clypeus and the frontal carinae. For the frontal carinae, I’ve started experimenting with different width profiles available in the Stroke panel, and with the Width tool (Shift+W) to make my own custom profiles. This allows the line to taper quite elegantly.

Drawing interior characters such as the frontal carinae and the clypeus. Notice the fine tapering of the frontal carinae achieved by a custom width profile available in CS5.


Step 7. The antennae are next. In general, it is best practice in AI to draw complete closed shapes when possible. That’s what I do with the antennal condyle and torulus and whatever that part is that is basal to the condyle. Sometimes I’ll do all the antennal segments, but more often I’ll just do the scape and leave it at that.

Drawing the antennal scape.


Once I’ve outlined and closed all the shapes of the antennae, I fill them with white and arrange them forwards (Control+]) and backwards (Control+[) to get them in the right order.

Step 8. Rotate (R) the antennal scape to horizontal position. I usually group the parts that I want to rotate together. This is my personal preference, but many other illustrators seem to prefer the scape aimed towards the posterolateral corner of the head. Up to you!

Scape rotated to horizontal position. This keeps it from obstructing the face, but doesn't allow you to see how much it exceeds (if at all) the posterior margin of the head.


Step 9. Copy and flip your artwork. Select all your artwork, copy it, paste it to back (Control+B), and flip it across its vertical axis (Transform > Reflect).

Artwork is copied, pasted and flipped.


Step 10. Then, while the copy is all selected, drag it while holding down Shift (to keep it on the same axis) until the midpoints of the head line up exactly. Select pairing points where they meet at the midline with the direct select tool (A) and join them, each in turn. This is essential for when the shapes are filled with color.

Sometimes the outline will be narrower than the actual specimen image. When this happens, I select everything with the regular selection tool (V) then drag one of the sides out. This makes all the shapes wider proportionally, so it introduces a little discrepancy (of the eyes for example) in return for a more accurate head width.

Two symmetric sides of head are moved and joined to become one full head.


Step 11. Now I like to do the mandibles. I’ll do whichever is in front, then copy, paste and reflect it for the back one. Again, make sure to close the shape. Don’t worry about the inner margin overlapping the clypeus — that will get sorted out later.

Mandibles drawn as closed shapes.


Step 12. Hide the photo template layer.

Photo template layer is hidden. Notice the I also made a new layer for the scale bar.


Step 13. Fill in the head and mandibles with white (or a different color if you prefer). Then arrange different elements backwards and forwards within the layer to achieve the proper order.

Now you’re done! At this point you can adjust the artboard (CS5 only), add text, etc. If you want to add hairs, follow the directions of my illustrating ant hairs post.

All done!

How to improve Lucid3 thumbnails

One of the greatest assets of the Lucid3 software is its capacity to integrate thumbnails of images inserted for character states, features and taxa. Once you insert a full-size image as media, Lucid3 automatically generates a thumbnail. The default thumbnail size is 125×125 pixels, but the user can customize it in Lucid Builder. The resulting thumbnails, however, are rather low quality, and can be significantly improved by using a third party application. I use Picasa to generate my thumbnails, but I am sure there are many other programs that will do just as fine a job. So, here’s how I do it.

1. Locate your thumbnail folder in Key folder > Media > Thumbs. Remember not to change the names or structure of the files within the key folder, because this will have nasty consequences. Notice how all of the thumbnails have the “_TN.jpg” suffix appended to the filename.

2. Copy the ‘Thumbs’ folder to some safe holding space like the desktop to serve as a backup in case things go wrong.

3. Delete all of the images within the ‘Thumbs’ folder.

4. Open the application you plan to use for generating the new and improved thumbnails. In my case, I use Picasa.

5. Open the ‘Images’ folder (Key folder > Media > Images), select all the files, then export them to a new folder (e.g. ‘New Thumbnails’) as 125×125 pixel jpeg’s (or whatever size you’ve customized your key to use).

6.  Now we need to append the ‘_TN’ suffix to the new thumbnails. I use a program called ‘Bulk Rename Utility‘. Open the ‘New Thumbnails’ folder in Bulk Rename Utility. Select all the files. Type ‘_TN’ into the Suffix form of the Add box. Make sure all the files have “_TN.jpg” at the end of them in the ‘New Name’ column. Press ‘Rename’.

Bulk Rename Utility is used to append the '_TN' suffix to the new thumbnails.


7. Copy all the updated thumbnail files from the ‘New Thumbnails’ folder into the ‘Thumbs’ folder (Key folder > Media > Thumbs).


Original thumbnails generated by Lucid3

New thumbnails generated by Picasa

8. Reload your key in Builder and check for any missing thumbnails. If you find a missing thumbnail, check the file path in the media tab, and then search your ‘Thumbs’ folder for the same filename. Often I find that I need to insert a ‘_1’ before the ‘_TN’ because I’ve accidentally imported multiple copies of the same full size image into Builder, which then automatically appends the ‘_1’ to full size image in the ‘Images’ folder.

Well, the jpeg’s published here do not quite do justice to the difference in quality, but rest assured that replacing the original thumbnails with your own will dramatically improve the aesthetic and quality of your key’s media.