Wednesday, July 8, 2020

Summer Damselflies

Summer is the time for procreation!   Here "dancer" damselflies (Argia spp.) are laying eggs in McDowell Creek.   The pairs have mated, and now the females are placing eggs in underwater vegetation or other substrate.   The males are "mate-guarding"--hanging onto the females and keeping other males at bay.


That clicking noise you're hearing is the breeding chorus of Blanchard's Cricket Frogs--also abundant near McDowell Creek.

The males have little grabbers on the end of their abdomens which fit exactly into slots behind the females' heads.  The exact fit means they can hang onto the females of their own species but no other.  


Here the males appear to be pushing the egg-laying females down into the water.  But don't worry--the females grab a bubble of air and keep breathing, even under water.     

Soon the eggs will hatch into aquatic larvae, called "nymphs."  Both the adults and the nymphs are great predators, feeding on mosquitoes and other insects in the air and in the water.   


Damselflies hate pollution, so their presence indicates a healthy stream.   These Dancers love streams with limestone bottoms, such as McDowell Creek.

Damselflies don't go through a complete metamorphosis--there is no pupal stage.  Instead, the aquatic nymph molts and grows and finally climbs out of the water to molt one final time.  The exoskeleton splits open and out comes a gorgeous damselfly, a beautiful adult with wings!




Damselflies are in the same family with dragonflies but they are smaller and thinner, and when perched they hold their wings upright, whereas dragonflies spread out their wings. 


Damselfly holding wings upright.  See how thin he is
compared to a dragonfly?

Dragonfly holding wings outspread.  See how hefty he is
compared to a damselfly?


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