Thursday, May 23, 2013

Damselfly Parasitized by Water Mites

Damselfly with Water Mites
As you observe nature, you are always learning something new.  I was out photographing damselflies today, because I wanted to try to obtain some photographs of spreadwing damselflies.  After downloading my photographs to my computer today I noticed a damselfly with what appeared to be brown growths, mainly on its thorax.  On further investigation, these growths turned out to be water mites.  Well, I learned something new today.  There are apparently to main families of water mites that attack dragonflies and damselflies.  One family, Arrenurus mites follows this life-cycle: adult female mites lay eggs that hatch into larvae, which seek out and attach to, but do not parasitize larval damselflies and dragonflies.  When the damselfly of dragonfly emerges, the larval mites scramble on to the newly forming odenta, where they pierce the host exoskeleton and feed on external digestion of the host tissues and hemolymph.  As the damselfly nears sexual maturity the mites completing gorging in the successful mites drop off the adult host as it nears or over the water, where the mic goes through two nymphal stages.  The other family of water mites, Limnochares, eggs Hatch into larvae that climb onto emergent vegetation, where they attach themselves to perching dragonflies.
Close-Up of Water Mites on Thorax of Damselfly