Extension Communications
3614 Administrative Services Building
Ames, Iowa 50011-3614
(515) 294-9915
7/31/03
FOR IMMEDIATE RELEASE
Contacts:
Mary Harris, Reiman Gardens, (515) 294-2567, maharris@iastate.edu
Jean McGuire, Continuing Education and Communication Services, (515) 294-7033,
jmcguire@iastate.edu
Iowa's Got the Blues
Mary Harris
Curator
Christina Reiman Butterfly Wing
The Blues are a source of fascination for both music and butterfly lovers. The Lycaenidae family, to which the small butterflies commonly known as blues, hairstreaks, coppers and metal marks belong, is a large family of approximately 4,700 species distributed throughout the world. In North American there are 32 species of blues; two are common in Iowa - the Eastern Tailed Blue (Everes comyntas) and Spring Azure (Celastrina argiolus).
Blues are small butterflies with an average wingspan of only one inch. The blues are further distinguished as including the smallest butterfly in the world, the Western Pygmy Blue (Brephidium exile). This tiny butterfly has a wingspan of merely 3/4 inch in width and occurs in the Western U.S. occasionally as far east as southwestern Iowa.
A second common name for blues is gossamer-winged butterflies. This name undoubtedly arose as a description of the light, iridescent blue of the wings. A closer look should reveal distinct white rings around the eyes and alternating white and black bands on the antennae. When you see the combination of these characteristics you can be sure you are watching a blue.
In Iowa, the Spring Azure is one of the earliest butterflies to be seen. Generally, it flies from May through September. The Eastern Tailed Blue flies from May to October and can be distinguished by the tiny curved tail on the hind wing.
Although common, blues are often overlooked due to their diminutive size and their flight habits. Unlike the large slow flying swallowtail butterflies, blues have a fast, often erratic flight. Blues are tasty treats for predators and must rely on maneuverability to elude capture. However, puddling (taking in moisture along the edges of mud puddles) is a common behavior of blues. A butterfly watcher can get the best looks at these elusive butterflies while blues are engaged in this activity.
Another behavior common among the blues is that of patrolling by the males in search of females. Eggs are laid singly on leaves of dogwoods and wild cherry for Spring Azures and herbaceous legumes for Eastern Tailed Blues. The caterpillars of blues are shaped more like slugs than most caterpillars. They are somewhat flattened with a head capsule that can be retracted within the prothorax. Short hairs often cover these caterpillars.
Ants are a common predator of many butterfly larvae. Not so with the blues, as these caterpillars are often protected and even fed by ants. Such caterpillars produce honeydew to feed their ant bodyguards. Some Lycaenid caterpillars produce pheromones that cause the ants to carry the caterpillar into the ant nest. Once ensconced in the nest, the caterpillar feeds on ant grubs.
Most species of blues feed on only a few closely related plants within a single family. This characteristic, combined with widespread human disturbance, is contributing to extinctions of many species of these butterflies worldwide.
The Xerces Blue Butterfly, Glaucopsyche xerces, once inhabited the sand dunes around San Francisco Bay. This is the first butterfly species in North America known to be driven to extinction by human disturbance. Two human problems are believed to have contributed to the demise of the Xerces Blue: loss of habitat and introduction of an exotic species. As homes and other structures are built, insufficient numbers of host plants remain on which caterpillars must feed. The introduction of the invasive Argentine ant, Iridomyrmex humilis, worsened the plight of the Xerces Blue. The Argentine ants do not tend Lycaenid caterpillars. Furthermore, these exotic ants displaced the native species of ants that tended the larvae of the Xerces Blue. Unfortunately, similar species losses of blues are occurring throughout the world.
When you are out this summer watch for these dainty butterflies as they
visit flowers or frequent puddles. And of course, if you would like inspiration
for your butterfly search, come visit the Christina Reiman Butterfly Wing
where butterflies from around the world are free to fly within the exhibit
year round.
To learn more about the Reiman Gardens at Iowa State University visit
us on the Web at http://www.reimangardens.iastate.edu/.
-30-
|
Editors: A color photo, suitable for publication, is available at right. Click on the thumbnail photo to go to the fullsized photo. The picture's fullsize photo is 188K. Caption: Eastern Tailed Blue |
 |
Extension programs are available to all without regard to race, color, national origin, religion, sex, age, or disability.