Tag: arthropods

Photographing butterflies

I took a break from curriculum development on Tuesday and drove down to Pinnacles National Park. Of course I looked at the incredible rock formations for which the park is famous. But as spectacular as the scenery was, the highlight of the trip was watching butterflies in Bear Gulch. In particular, I spent about ten minutes watching one Western Tiger Swallowtail visiting larkspur blossoms. I took a great many photographs of this one butterfly, getting as close as I could. With a photograph, you can capture narrow slices of time: the position the butterfly’s wings take as it balances on a flower; the way it clings to the flower with its legs and arches its head towards a blossom; the moment when the butterfly is just approaching the flower:

Papilio rutulus

But sometimes what sticks in your memory is not what you actually saw, but the photographs of what you saw. After I left Pinnacles, I drove to Elkhorn Slough National Estuarine Research Reserve. When I saw butterflies there, I made a point of trying to sketch them in my field notebook rather than just photograph them, like this common butterfly:

Vanessa atalanta

This sketch, as an end product, is not nearly as attractive as a photograph (and I did take a photograph of this insect as well) — it’s not as attractive, but I learned more about butterflies by making this sketch. By comparing my sketch to a field guide, by seeing what I left out, I learned what I don’t see when I look at butterflies. I suspect making less attractive sketches like this does more towards sharpening my powers of observation than does taking a great many very attractive photographs.

Ants

Recently, I stumbled across the AntWeb site, sponsored by the California Academy of Sciences. Once you create a login (and all you have to provide is a username and password, no other info), you have access to tons of photographs of ant specimens, taken through a powerful microscope. Of particular interest to me is the online field guide to California ants, with photos of nearly all of the 270 resident species. The curator of the California pages writes:

“Prominent California ants include seed-harvesting species in the genera Messor, Pheidole and Pogonomyrmex; honeypot ants in the genus Myrmecocystus; a diverse array of species in the genera Camponotus (“carpenter ants”) and Formica; native fire ants (Solenopsis spp.); velvety tree ants (Liometopum spp.); and the introduced Argentine ant (Linepithema humile). This last named species is particularly common in urban and suburban parts of California, where it establishes dense populations and eliminates most native species of ants.”

I’ve always thoughts ants were interesting creatures. Now having looked through dozens of photos of ants I will go further and say that they are beautiful creatures. Even the Argentine ant appears beautiful, in spite of the destruction it does to native arthropods.

I am also fascinated by the written descriptions; these descriptions have their own kind of beauty, which may be found in their economy and laconic precision. Here, for example, is how to identify the Argentine ant — remembering that you will need a powerful binocular microscope to see all these details:

“Diagnosis among workers of introduced and commonly intercepted ants in the United States. Antenna 12-segmented. Antennal scape length less than 1.5x head length. Eyes medium to large (greater than 5 facets); do not break outline of head; placed distinctly below midline of face. Antennal sockets and posterior clypeal margin separated by a distance less than the minimum width of antennal scape. Anterior clypeal margin variously produced, but never with one median and two lateral rounded projections. Mandible lacking distinct basal angle. Profile of mesosomal dorsum with two distinct convexities. Dorsum of mesosoma lacking a deep and broad concavity; lacking erect hairs. Promesonotum separated from propodeum by metanotal groove. Propodeum with dorsal surface not distinctly shorter than posterior face; angular, with flat to weakly convex dorsal and posterior faces. Propodeum and petiolar node both lacking a pair of short teeth. Mesopleura and metapleural bulla covered with dense pubescence. Propodeal spiracle bordering posterior margin of propodeal profile. Waist 1-segmented. Petiole upright and not appearing flattened. Gaster armed with ventral slit. Erect hairs lacking from cephalic dorsum (above eye level), pronotum, and gastral tergites 1 and 2. Dull, not shining, and color uniformly light to dark brown. Measurements: head length (HL) 0.56–0.93 mm, head width (HW) 0.53–0.71 mm.”