My title reminds me of Fred Astaire and Ginger Rogers. For the younger generation, I suppose other
movies come to mind, maybe with Richard Gere; but how many of you think of
flies? Yes, flies. There are some marvelous dancing flies – especially
midges and dance flies. A few days ago
Dale and I were watching dance flies.
The fun began on a sunny day. I
want to say ‘a warm sunny day’ but it wasn’t all that warm – about 60
degrees. Spring flowers are just coming
out; grass is growing; bumble bees and dance flies are on the wing.
First let me introduce the characters in this little
saga.
This is a female dance fly (Family: Emphididae.
Subfamily: Emidinae). Her abdomen
is very pointed and her eyes have a little space between them. Many female flies have a space between their
eyes whereas the male’s eyes often touch.
She is sipping nectar on an English daisy, an early spring flower which is about an inch across.
And here is a male.
Note his eyes are close together and he has a lumpy rear. Both are small, about as long as a good sized
house fly.
Note: Emphididae is a
very diverse family, so what I observed does not necessarily apply to all
‘dance flies.’
I’m looking for insects visiting one of Oregon’s early blossoming bushes, a red
current. A big queen bumble bee zips
from one flower to another, there are several honey bees, a hairy flower fly
visits momentarily...
I’m missing the real excitement! Off to the side I see half a dozen small
flies circling up and down in a patch of sunshine. The sun hits the sturdy hog wire fence that
surrounds the garden where I stand. The
flies could easily fly between the square openings; instead the fence seems to
provide an invisible barrier. The flies
bounce up and down in front of the fence – dance flies!
Since the fence seems to be a barrier, I have a chance of
getting a photo of one.
I love the challenge of photographing birds and bugs ‘on the
wing.’ These are difficult, but once I
succeed in getting a reasonably sharp shot, I can see it’s a male carrying a
nuptial gift, hoping for an interested female to come along. I photographed the female, shown at the
beginning of this blog, five years ago.
Afterwards I read about these dance flies and hoped someday I’d get to
see more.
Here I am, with a dance fly dancing in front of me! He carries a fairly heavy load – circling up
and down in the sunshine. He even lands
to rest for a few minutes before continuing on with his dance.
Suddenly a second fly zooms in and the two briefly spiral
together -- sorry, no photo of that!
This male and female zoom up into a tree above me. Out of sight.
Soon I try to focus on a second male. Midair he connects with a female in front of
me! The two land on the stem of a wood
vine which grows on the hog wire fence. They
have far more on their minds than Dale’s and my cameras.
I see how useful those long legs are. The male actually hangs from the wood vine
stem with his two front legs. His second
and third pair of legs reach down and around the female while he continues to
hold onto his nuptial gift – a march fly (Bibio sp.). While the two dance flies couple, the female dines
on a march fly slurpee i.e. she inserts her proboscis into the fly and sucks
its juices. I can even see the
protective sheath which covers her proboscis until it is time to feed.
Here is a view of a second pair. This male landed on the hog wire fence and faced in such a way that shows off his long front legs; his middle pair holds onto her head; and his third pair still holds onto his nuptial gift -- a rather small offering this time.
Other members of this genus can be quite devious. The male creates an obvious ‘nuptial offering’ out of either silk or bubbly froth …. And this
is where the devious part comes in.
Sometimes the ball contains a real offering for the female and sometimes
it is empty! The dance flies I was
watching were good, stalwart fellows, offering their ladies a juicy insect in
return for favors wanted.
