by 
Paul Landau’s photo of a Pipevine Swallowtail.
Superior – Why do some butterflies have iridescent blue-black wings, and a foul taste, repulsive to birds and other predators? We asked Tempe resident Ron Rutowski, who teaches biology and has been a professor at ASU since 1976.
Rutowski and his team of graduate and undergraduate students are fascinated by how color is produced, employed and perceived in the animal kingdom. Their main focus is on the ways insects use color as a visual signal, and, how it’s interpreted by their compound eyes.
Research has taken Rutowski across North and Central America and Australia. We caught up with the engaging biologist, who says one of the most compelling insect interrelationships can be observed right here in central Arizona. Rutowski is very familiar with the butterfly fauna of the West; he’s an Arizona State Parks volunteer, and leads the next butterfly walk at Boyce Thompson Arboretum (BTA) at 8:30 a.m. on Saturday, Aug. 22. This, as with other weekend nature walks, is included with $10 park admission.
When asked what months are best to see butterflies in Arizona, Rutowski stated, “Arizona gets two pulses of rain each year: the winter rains from November to March and the summer monsoon rains in August and September. Because butterflies are so dependent on plants, the adults for nectar to sip and the caterpillars for leaves to munch, and, because our most luxuriant plant growth follows the rains, the spring and fall and not the
summer are good times for looking for butterflies. That being said there will certainly still be butterflies to be seen in June, just not quite as many individuals and not quite as many different kinds as in the spring and
fall.
On the subject of Pipevine Swallowtails, why they occur at Boyce Thompson Arboretum and what is so unusual about them, he shared, “Dutchman’s Pipe, the plant eaten by Pipevine Swallowtail caterpillars,
is common at BTA and in the surrounding desert; what’s unusual is the iridescent blue color of adult butterflies. For many years a focus in my lab has been on iridescent colors. These colors by definition are directional which means they change rather dramatically in appearance depending on the positions of the iridescent animal and the animal looking at it. Biologists have thought for years that this must present special challenges for the animal to make its iridescent color apparent to an intended receiver.
So, how do they deal with this directionality? The Pipevine Swallowtail is a great subject for studying this question because they have iridescent blue patches on both their upper and lower wing surfaces. The blue on the upper wings surface is found only in males and is a sexual signal. So, how do males present this signal to females in courtship? The lower wing surface blue is part of their warning coloration that predators learn to
associate with the fact that these animals are very unpalatable. So, how does the directionality affect the ability of predators to learn this association? Our answers to these questions should be helpful in understanding the behavior of other organisms with iridescent coloration and animal communication systems generally.
Rutowski is a colorful character, himself. Unlike the common stereotype of a butterfly enthusiast, he did not pin colorful butterflies into boxes when he was a kid. On this subject, he stated, “No. I was interested and committed to biology by my early teens , and, at that time my focus was on birds. Birdwatching was an activity my father and I started doing together.
“My first real interaction with butterflies was as a high school senior in an advanced biology class that made regular trips to a nearby canyon in near Los Angeles and kept lists of animals and plants seen there over the course of a year. After high school my interest in birds persisted but became more focused on animal behavior and communication. When I got to graduate school I became quickly convinced by my Ph.D. advisor, Dr. Thomas Eisner, of the many interesting and unanswered questions about communication in insects, especially visual communication in butterflies. That was the beginning of a focus on butterflies and the production and function of visual signals that has persisted throughout my career.”
Arboretum visitors had special treat, last November, being allowed a peek at a different side of Rutowski’s talents and interests. While colorful butterfly wings give him the flutters, Rutowski also enjoys playing the fiddle in the band Trio Rio. Rutowski said, “I started playing violin when I was 10, after three years of relatively
unsuccessful piano lessons. Over the years I have become increasingly involved in various non-classical musical genres including bluegrass, country, and jazz. Currently, I work with a band called Trio Rio with Ronnie
Glover and Don Paddock. We play fairly regularly at several venues in Scottsdale and Cave Creek. “
The band’s schedule can be found at triorioaz.com.. Information on the BTA, including current event schedules, can be found at ag.arizona.edu/bta/.
There are news or informational items frequently written by staff or submitted to the Copper Basin News, San Manuel Miner, Superior Sun, Pinal Nugget or Oracle Towne Crier for inclusion in our print or digital products. These items are not credited with an author.
by by