Friday, August 26, 2011

Larvae* at Large

You can see a lot just by observing.—Yogi Berra
What you see is what you see.—Frank Stella

So, just what was to be seen today? The first animal that got our attention was a hawk, in flight and calling. David and I agreed it was either a Sharp-shinned or Cooper's and a good start to the day. And heading over to the pond, seeing a single nymph (below) led to seeing dozens.
What: Abundant exuviae, the discarded exoskeletons left by dragonflies in their transition from aquatic larvae to terrestrial, winged adults. (Resource: Dragonfly Biology 101)
Where: Clinging to aquatic plants growing in the shallow west edge of the pond at Spoonbridge and Cherry
Observers: Abbie, David, and Elizabeth
Date/Time: Friday, August 26, about 10:10 am
Conditions: Sunny. July's oppressive heat is a thing of the past.

As a phenologist, albeit an amateur, this observation prompts important questions. First, what species were we seeing? Just one or a few varieties? These exuviae were about 1.5" long, and had I been vigilant, I might have glimpsed a dragonfly making its exit. Second, when exactly did these nymphs emerge? I didn't notice them last week, but had I simply failed to see them? Or was this legitimately a recent phenomenon?
What: Caterpillar, unidentified and stationary
Where: Eye-level on a flowering plant, arbor at the north edge of the Sculpture Garden
Observers: Spotted by David, observed by Abbie and Elizabeth
Date/Time: Friday, August 26, 10:35 am

What: Another unidentified caterpillar, this one was scurrying across the sidewalk
Where: East edge of the Sculpture Garden, base of the stairs to the Irene Hixon Whitney Bridge.
Observers: Abbie and Kristen
Date/Time: Friday, August 26, at about 11:30 am

*Larva (plural larvae), is Latin for 'ghost.' A larva is the juvenile form of any animal that undergoes metamorphosis into its adult form. A caterpillar is the larval form of moths and caterpillars, while nymph is the larval form of dragonflies and damselflies. All this talk of larvae reminds me of the Goldenrod Gall Fly, that saccharine treat I learned about when Sarina joined Open Phenology on July 8.

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