The Colorful Megalagrion damselflies are unique to the Hawaiian Islands.
Megalagrion blackburn is a large, red species that is endemic to Maui, Molokai, and the Big Island
A single species arrived some 12 million years ago to the islands and evolved into 23 native species. See them in our Megalagrion Gallery.
One of the many impressive things about Hawaiian damselflies is that they live in every possible damselfly habitat – in open streams and rivers, in small streams and pools, in seeps and waterfalls, and even away from the stream on plants and in leaf litter.
Damselflies make their living with their huge eyes — they rely on vision to catch prey, identify mates, and recognize predators — but many live in dim habitats.
How do they see well in dark, cluttered habitats?
One answer is that they have evolved eyes to match the type of habitat they live in. Insects have compound eyes, which means that they view the world as an image formed by “pixels” – (remember “the fly”?) Since they are small animals with small eyes, they will have a tradeoff between visual sensitivity and resolution. The smallest animals actually live in the darkest habitats, and they increase resolution by regional specialization of the eye.
We have been studying their visual system, their light habitat, and behavior to understand how these animals can not only contend with visual challenges, but how variation in habitat light promotes the evolution of biodiversity. This work was generously supported by NSF IOS 0958509 to MAB.