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| Puddling party in the valley - REK |
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| Juvenal's Duskywing - REK |
We
are seeing lots of Duskwing Skippers the last week, clustered in groups
of 50-100 plus gathered on dry sand in our gravel drives. These are
the Rodney Dangerfields of the butterfly world and some would even go so
far as to separate them from butterflies altogether. The duskywing
skippers are notoriously hard to identify by species and only the fact
that I was seeing such large numbers at
scattered sites made me curious enough to the trouble to ID
them.
These are all Juvenal's Duskywings,
Erynnis juvenalis. They are nearly identical to
Horace's Duskywings and both were named for Roman poets for unknown reasons. The marking details separating the two species are very minute, one
requiring pulling the forewing forward to expose two tiny white apical
spots, cumbersome for me and I suspect embarrassing for the butterfly.
From now on I will confidently call them Dusky Skippers and skip on to
the next species.
Juvenal's Duskywings fly earlier in
the year than Horace's. Juvenal's was one of the first North American
butterflies to be described. They were initially associated with dry,
sandy regions with shrub oak but are found anywhere in the eastern US
where their caterpillar host plant oaks occur. Oaks occur all over our
land so they have a lot to choose from.
Males will cling to branches along the edge of woodlands and patrol for
females. Eggs are laid on early oak leaaf buds or seedlings where their
caterpillars will feed on leaves and rest in nests of rolled or
tied leaves.
Puddling or
mud-puddling
behavior is observed in lepidoptera and a few other insect species. It
is a way for them to collect minerals such as salt similar to what
sweat bees do landing on our skin in summer. Some species will do this
on animal dung, presumably collecting ammonium. These gatherings are
predominately male as they collect sodium and amino acids which they
then transfer to the female as a "nuptial gift" delivered with their
spermatophore during mating. It is common to see several species puddling together in the summer.
When
I began writing this I suddenly noticed something else about the
puddling photograph. While the Duskywings wingspan measured less that
1.5" there was something even smaller on the sand. See if you can spot
them in the picture at the top.
There are two tiny black moths with multiple white spots on their wings. These are Mournful Thyris,
Thyris sepulchralis with a wingspan of less than an inch
. While most moths are out at night, these are day flying moths
that
feed on flower nectar and are noted for collecting fluid on moist
sand. Our sand appeared dry to sight and touch but many species shoot
fluid out their rectum to moisten the area and dissolve the salts for
absorption.
(Note to self - wash hands after testing sand).
One photographic trick is to pour a little salt water on the ground and wait for butterflies to puddle for the camera.
Some photographers suggest placing a decoy of a dead butterfly or even a piece of colored paper to attract species in the neighborhood.
A naturalist, most likely but not necessarily male, may chose to supply
ammonium in the form of urea from a convenient resource.
Find the moths? Click on this picture.
Find the moths? Click on this picture.
