The Dragonfly : Hunting Ace

The Flight section of Bug Lab features New Zealand’s own ranger dragonfly (Procordulia smithii) as the star, showing off in style in our marvellous zoetrope. Weta Workshop head Sir Richard Taylor might know the movie business inside out, but that hasn’t stopped him being a fan of this pre-film technology.  I don’t want to say too much about this because I don’t want to spoil the surprise. Until you see it, you’ll just have to take my word that it’s a celebration of the dragonfly doing what it does best and is an absolute delight.

Dragonflies belong to the Odonata, an insect order that’s been around for about 325 million years. Their ancestral cousins were very much larger than modern species and some fossils show wingspans in the order of 75cm or so (check out our model!). Dragonflies are our Flight stars for two reasons. First, they’re amazing aeronauts. Our best aircraft simply can’t match them for agility. Second, they’re incredible hunters. A lion hunting alone might catch its prey around 25% of the time, but dragonflies have around a 95% success rate. The lion might be called the king of the beasts, but it’s not king of hunters. 

How are they so good at flying and hunting? Work by US researchers Anthony Leonardo and Stacey Coombes gives us some insight. Dragonflies are an incredible combination of visual processing and aerial agility. First of all, a dragonfly locks onto a target. We might be distracted trying to pick one target out of a cloud of dancing mayflies, but a dragonfly can pick one target and ignore the rest. Dragonflies also see at around 300 frames per second (we see about 60 fps). The dragonfly would see our zoetrope as virtually static, but seeing the world in slow motion compared to us helps them with hunting. They can quickly process all that visual information to predict where the target is heading and they constantly adjust their inflight body position to make the interception.  They can make those adjustments so easily because they can control each of their four wings independently. We have a model dragonfly wing in the exhibition to show you how the different parts combine to help make these insects such incredible aviators. Our Flight lab table also features interviews with Anthony and Stacey so you can hear from some experts who know these animals so well.

While we can’t fly as well as a dragonfly, insect flight is inspiring the ever-growing field of drone engineering. We have a couple of examples in the exhibition, including the Robobee from Harvard University. As the name suggests, it’s about the size of a bee and is one of the smallest functional drones around. At the other end of the scale, we have a life-sized model of a griffinfly, the dragonfly’s ancient relative. It has a wingspan over 70cm across and it’s quite startling to realise insects this size once ruled the air. If you want to have a go at insect flight yourself, we can’t give you wings, but we can give you paper. You can turn this into an origami butterfly and test its airworthiness in our wind tunnel. It also makes a nice memento of your visit it Bug Lab!

Dr Phil Sirvid looks after the entomology collection at Te Papa and has an inordinate fondness for spiders. He is one of the swarm of people that helped develop the Bug Lab exhibition.