Weather

I was advised something big might be coming, but disregarded the message: flies were gathered in remarkably large slow-moving clusters on the shrubbery, ground and fences under the overcast sky. Instead of making the connection between this phenomenon and the weather forecast (a slight chance of showers), I silently cursed whoever it was that neglected to clean up after the dog.

Then, just a few hours later that evening an astonishing thunderstorm arrived.
Here in OC we don't get thunder and lightning very often, so a storm that lasts all night and most of the next day becomes the stuff of legend.

But what about those flies? A quick search for references to rain-predicting folklore informs me that "flies fly low and/or gather in numbers before rain and severe storms". Huh, how about that? Come to think of it, I've noticed that about flies before but hadn't taken them seriously as weather predictors. So if folklore is accurate, is it science? Oxford defines science: "a branch of knowledge involving the systematized observation of and experimentation with phenomena." And folklore: "traditional beliefs and stories of a people." I'm a people; I observed flies predicting weather; and now I'm telling a story about it. To move my new-found fly lore more firmly into the domain of science, a series of controlled observations of fly behavior relative to weather would be easy to set up but tedious to perform: noting the numbers of flies, their flight speed and types of other activities, the barometric pressure, humidity, temperature and of course the incidence of rain. Maybe it's already been done; Vincent G. Dethier would be a prime suspect for such a study. Check out his interesting little book, To Know A Fly.

If science was less work, perhaps we would have no folklore. For now, I'll file the flies' predilection to prediction somewhere between science and lore; right next to the TV meteorologists.

A few bugs that got wet in our welcome bit of rain:
some green lynx spiderlings

a katydid,

and of couse, a fly.

9/22 note: The flies under investigation as signs of rain are our ubiquitous green bottle flies, phaenicia sericata. I wonder if these widespread species adapt to local conditions, and so exhibit behaviors specific to a region; for instance if they are reacting to either humidity or barometric pressure, could the range that bottle flies react to in my area be lower (for humidity) or higher (for pressure) due to the prevailing norms. Kind of like how southern Californians (humans) put jackets on when it's 60 degrees F. Just wondering.