A Robber Fly
"Bugging." According
to my dictionary, 'bugging' should mean I'm annoying someone, or perhaps I'm
recording someone surreptitiously. I'm
using this word more and more, but not in the normal way. Instead of asking Dale, "Am I bugging
you?" I am often saying "Are we going bugging?" It's like "Are
we going fishing?", only I'm asking whether we going to go look for insects. Obviously saying, "Are we going
insecting?" doesn't work.
We've been doing a lot of bugging since digital photography
came along. The camera gives us an
up-close and personal look at their world. Over and over I'm amazed at what I
see through my camera lens .... and, more importantly, what those little
critters are up to.
Today we started the day by getting so close to a robber fly that
we could photograph the individual eyes in its compound eyes. Those eyes look dark and mysterious to
me.
When we go bugging, we aren't intentionally heading out to
door to be citizen scientists. We're
going bugging because we are enjoying their discovering their world. Bugs are fascinating! It happens that in the process we often are
'citizen scientists' -- see my last blog post for more on that subject.
July 11, 2016: Douglas County, Oregon
Today my big discovery involves two species, predator and
prey. Dale and I are bugging with
friends at a little pond about 20 miles west of here, Iverson Pond. The day started cool and cloudy, but we
trusted the weatherman's promise of a sunny afternoon. Sure enough.
By early afternoon the temperatures are above 70 and the sun is out most
of the time. Insects are out and about.
First treasure is watching a Klamathweed beetle preparing
for takeoff. Technically beetles have
two sets of wings: the first pair, the
elytra, is the hard pair that forms the covering on the beetle’s back and
protects the second pair, the pair used for flying. Beetle flight wings are neatly folded under
the elytra until the beetle wants to fly.
Suddenly I realized a little beetle is raising those eletra,
revealing bright red wings, rather like the old nanny's petticoat in "Gone
with the Wind" -- shockingly
red.
And then we watch the amazing process of thin, delicate
wings unfolding. But the beetle didn’t fly. It neatly folded those bright red petticoats
out of sight again.
I'm always looking for new habitat. That's the best way for finding new
insects. I've worked the edge of the
pond more than once, but I've never scrambled all the way down the steep slope
formed by the pond's dam. The slope is
lush with long grasses, hundreds of daisies and some digitalis. The toe of the slope is bordered by a thick
tangle of willow. I wonder what I will
find along that edge of willow.
I’m not disappointed.
Near the willows I quickly spot gaudy black and orange caterpillars --
some are quite big. Smaller ones, about half
an inch long, cluster together. Pretty,
but they are demolishing their host plant.
Then I realized the host is tansy ragwort, an invasive weed that can
kill cows and horses if they eat too much of it. By the 1950s the weed had become a serious
problem in Oregon pastures. In the 60s
and 70s three insects were introduced to help control it. The results were remarkable, but flare-ups
still occur. I wonder whether these caterpillars
cinnabar moth caterpillars?
I immediately set about photographing caterpillars. There are fewer than a dozen tansy ragwort
plants, so I look at each one carefully.
There, tucked under the leaf of one, I find a snakefly! Snakeflies aren't really flies .... so
confusing .... they belong to a different order, Raphidiidae. Snakeflies are odd looking insects about 1.5
inches long. Their striking wings are
held vertically over their back and their long neck easily sets them apart from
most insects.
The snakefly I just found is feasting. It has discovered a cluster of eggs and itty,
bitty caterpillars that are just hatching out.
The caterpillars are translucent at this stage -- no color, but they have
the shape and little hairs that assure me they are probably the first stage of
the orange and black caterpillars I have just been photographing.
Dale calls out, trying to find me. I am sitting on the
ground, hidden amongst the tall grasses and daisies. Dear, sweet, man, he manages
to join me just in time to photograph the bright black and red moth that comes
flying by -- a cinnabar moth. So now we have eggs, tiny caterpillars, bigger caterpillars and an adult cinnabar
moth. They are probably all the same species. I also have a series of photographs
of the snakefly feasting on those eggs and caterpillars.
Now that's a good day of bugging!
Good day indeed! Keep bugging us with your adventures and talents. How often would you ever see so many stages of a single moth species in one day? Plus the predator!
ReplyDeleteGreat detective work, I've not known of the snake fly.
ReplyDelete