Odonate Nymphs

We’re back at Prince Albert National Park in Saskatchewan for our last week of insect collecting. It’s a fitting location considering that this is where Jon and I began our trip on the BIObus back in early July.  Today we spent some time aquatic sampling at Mud Creek Trail where we found Odonate nymphs. Odonates (my favourite insect Order) are dragonflies and damselflies, and while most people are familiar with the beautifully coloured adults, they wouldn’t recognize the equally cool aquatic juvenile stages of these insects.

Jon, Spencer and I collecting aquatic inverts in Mud Creek
The discarded skin of a large Darner dragonfly nymph. The adult emerges through the back.

Like the adults, Odonate nymphs are predacious. They have a modified lower lip (labium) that they can project out in a fraction of a second to snag their prey. They also have cool strategies to avoid their own predators. Dragonflies are capable of jet propulsion by taking in water and then shooting it out for a burst of speed. Damselflies have three feather-like structures at the end of their abdomen called lamellae, which are important for locomotion. Along with swimming and respiration, lamellae are also useful for escaping invertebrate predators (like the larger dragonfly nymphs). The lamellae of damselflies are capable of autotomy (or self-amputation), and will detach if grasped. A comparable vertebrate example is a lizard losing its tail. This allows the damselfly to swim away, and the missing lamella will regenerate in a few molts. Pretty cool!

–          Jen