Dragonfly Design

I almost feel bad posting on an insect that has received so such publicity, but I think I can come at it from a refreshing perspective. For starters, dragonflies are often considered flying creatures so, although they certainly seem to be a "creeping" sort today, they may have been created on day 5 of the creation week with the other flying animals (see Genesis chapter 1). However, dragonflies actually spend the majority of their lives underwater so perhaps they are better considered "swimming creatures." Some species can hunt on land (Grzimek, 1975), however, so perhaps the original kinds behaved this way, given that the world might have been more moist before the global flood. From that original kind came a menagerie of different species diversifying to fill the various ecological niches available to them. Those that found themselves in the Carboniferous forests grew huge, larger than many of today's hawk species. Damselflies, though superficially similar to dragonflies, do not share a common ancestor, I believe. This becomes apparent when one views the two kinds when they are in their aquatic nymph stage. Damselflies have large featherlike protrusions from their abdomen.
When one thinks of dragonflies, they typically envision a four winged, predatory insect of the air. The truth is, dragonflies are more of an aquatic species (as was mentioned above). They may spend up to five years as an aquatic nymph, breathing with gills (Dreves, 1993). They are amazingly well designed for this aquatic life cycle, doing anything a dragonfly would do except for breeding. To escape predators (like giant diving beetles or aquatic salamanders) they even have a system of jet-propulsion in which water is forced out the anus of the dragonfly (Mill et Pickard, 1975).
The mature dragonfly only lives a few weeks to several months, though this is when we commonly notice them. Not only are they simply obvious flying around any body of water, they are also brilliantly coloured during this stage.
Even as adults, dragonflies are amazingly well suited to life on the wing. They have four wings, each of which can manoeuvre independently of the others to propel the insect in whichever way it choses (up, down, sideways, backwards, you name it). While we might be inclined to think that our own eyes are the superior system for vision, they would hinder the dragonfly on his mission. With large compound eyes and a swivelling head, the dragonfly can see nearly 360 degrees of its surroundings (Dreves, 1993). The tens of thousands of lenses on these eyes are far better at picking up movement than simple eyes and can see a mosquito 40 meters away (Dreves, 1993), which is the equivalent of us seeing a mouse 1.5 kilometres away.
Catching prey can be difficult. Mosquitoes are relatively easy, flying a meagre top speed of 2 kilometres per hour. The average dragonfly at 29 kilometres an hour has no difficulty catching hundreds of mosquitoes in a day. Horseflies are more difficult, however, with an astonishing top speed of 145 kilometres per hour (speedofanimals.com). The great British-Australian naturalist Robin Tillyard claimed to have clocked a southern giant darner at 97 kilometres per hour (Tillyard, 1917), but even this debated number wouldn't be enough to catch a speeding horsefly (50 kilometres is considered a better estimate of top speed). Maneuverability and planning are the key to the dragonfly's success.
People have always been fascinated by the amazing designs of the dragonfly and the military often attempts to copy the design in their own fighter jets. Engineer Stuart Burgess recently wrote on the way that engineers are copying the dragonflies four-winged design for their own micro air vehicles (Burgess, 2012).
In order to do all this brainy hunting, dragonflies need to warm up every morning. They are cold blooded and need sunlight to give them the copious amounts of energy they will need. Once again,the intelligence of the dragonfly comes into play. To heat up as quickly as possibly, they tilt their wings and body to catch as much of the sun's rays as possible. As the day gets hotter, and the dragonfly feels a need to cool off, it will tilt its body to absorb as little of the suns rays as possible. Doing this allows the dragonfly to maintain a constant temperature throughout the day.


References:

Burgess, Stuart. 2012. “Bug Bots”. Answers. Vol. 7, No. 1. Jan-Mar 2012. Answers in Genesis—USA.

Dreves, Denis. 1993. “Dragonflies: Designed to Dart”. Creation. Vol. 16, Issue 1. December 1993. Creation Ministries International.

Grzimeck, HC; Bernhard. 1975. Grzimeck’s Animal Life Encyclopedia Volume 22. Visible Inc Press. Detroit. Page 348.

Mill, P. J. and R. S. Pickard. 1975. “Jet-propulsion in Anisopteran Dragonfly Larvae”. Journal of Comparative Physiology A: Neuroetholoy, Sensory, Neural, and Behavioral Physiology. Vol. 97, No. 4. Pages 329-338. http://link.springer.com/article/10.1007%2FBF00631969

Tillyard, Robert John. 1917. The Biology of Dragonflies. University Press, Cambridge.