Out of the Water and into the Lab: Dragonflies as Research Models
Those who work in invertebrate conservation frequently hear the question "why should I care?" asked by everyone from members of the general public to policy makers. What does it matter if an obscure fly species goes extinct? How important is a spring-dwelling snail in the larger scheme of things? What impact do declining lightning beetle populations have on my life? There are many answers to such questions, of course, from intrinsic value to ecological importance, and in recent years people have also made economic arguments, using financial assessments of the ecosystem services provided by invertebrate species. Others may point to a variety of biological compounds isolated from invertebrates with applications in human medicine due to their anti-microbial, anti-cancer, anti-inflammatory, and immunosuppressive actions. Odonates deliver an array of ecosystem services and have long been important figures in a variety of ecological research.
The MDP is using stable isotope research and data from citizen scientists to investigate the central question of how and why some dragonfly species migrate in North America, and we have new findings about their migration routes, the intensity of their annual movements, and the timing of their repopulation of northern breeding grounds. Other workers have employed dragonflies in research to understand mercury bioaccumulation or the impacts of climate change on life history and geographic range, and they have been effective as indicator species in water quality assessments. But people outside of the entomological world have also found dragonflies to be useful models in some different--and often surprising--avenues of research.
Dragonflies' iconic huge eyes not only have tens of thousands of lenses (ommatidia), research in visual systems has revealed that dragonflies also have 3-10 times more visual opsins (light-sensing proteins) than humans and other vertebrates, responding to short and long wavelengths as well as ultraviolet light. They have been the subject of studies in "infectobesity", an emerging field of research that examines the role of gut microorganisms on obesity in animals (including humans).  Studies of the development of metabolic abnormalities in the Twelve-spotted Skimmer (Libellula pulchella) may provide clues to causes and treatments of metabolic diseases such as diabetes in humans. A close examination of dragonfly wings revealed tiny spikes only 240 nanometers high (that's 0.000009 inches!) that acted to pop bacterial cells that attach, inspiring scientists to try to re-create this prickly surface on silicon in the hopes that it could provide an anti-microbial coating for medical devices. Their wings have also been the study of robotics research, with their acrobatic body plans used as a basis to build more agile flying mechanical systems, such as the Festo company's dragonfly-inspired BionicOpter.
These important discoveries are just a small illustration of the many ways in which dragonflies and damselflies have "added value" for humans not only for our increased understanding of ecology and the natural world, but also for unsuspected insights and advances in technological and biomedical research. For the MDP, future insights into dragonfly migration hinge on new discoveries made by researchers as well as the contributions of citizen scientists who track their populations and movements--working together from the pond to the lab to shed light on one of the most astounding phenomena in the animal world.