'Tis "Friday Fly Day" (also known as #Fridayflyday in the Twitter world), and it's almost Halloween.

So why not combine the two with a common drone fly, Eristalis tenax, nectaring on a pumpkin-orange Mexican sunflower, Tithonia rotundifola?

To the untrained eye, the drone fly is often mistaken for a honey bee. Both, however, are pollinators.

But the larva of the drone fly is known as a rattailed maggot and feeds off bacteria in drainage ditches, manure or cess pools, sewers and the like. Unlike a honey bee, the drone fly has one set of wings, large eyes, stubby antennae, and a distinguishing "H" on its abdomen. 

The drone fly will still be hanging around when Halloween arrives, but how many costumes have you seen glorifying the drone fly? The honey bee, yes! But a drone fly? No.

To be a fly on Friday, what a day!

Entomologists who came up with "Friday Fly Day" are having a lot of fun posting images on social media of flies on Friday.

If you access WikiHow, "What to Do on a Friday Night," you'll find all kinds of suggestions. For instance:

• Watch a movie  (that's do-able)
• Challenge friends to a game night (does anybody play games any more?)
• Treat yourself to a spa at home (a spa?)
• Give yourself a makeover (a what?)
• Cook a nice meal (how nice is nice?)
• Treat yourself to cocktail (some of us prefer coffee or water)
• Read a book or a magazine (did that, already)
• Start a new hobby (who has the time? Other hobbies are failing)
• Pamper your pet (he's already pampered; he has his own Facebook page, Vito and His Friends)
• Throw a karaoke or dance party (the neighbors would not like that)
• Work on an artistic or crafty project (some of us are crafty but not artistic)
• Start a bonfire (not in California!)
• Do something physically active (stationary bikes are good)
• and on and on and on....

Nowhere, but nowhere, does it say to take an image of a fly on Friday. 

It doesn't have to be a fly on a wall. It can be a fly on a flower. But it has to be a fly on a Friday. 

This one is a syrphid fly, aka flower fly or hover fly (and often mistaken for a honey bee) foraging on a blanket flower, or Gaillardia. 

Gaillardia, a genus in the sunflower family, Asteraceae, is named for an 18th century French magistrate/botanist, Maître Gaillard de Charentonneau.

Maître Gaillard de Charentonneau, no doubt, never observed Friday Fly Day but being a botanist, he probably loved pollinators. 

Cheers to a syrphid fly on "his" flower. (Well, it is a pollinator)

Have you ever seen a freeloader fly trying to sneak a meal?

Since it's Friday Fly Day--and the best things in life are free, aren't they?--it's time to post an image of a freeloader fly. 

So here's the story: a praying mantis was polishing off the remains of a honey bee, and uninvited dinner guests--freeloader flies (family Milichiidae, probably genus Desmometopa)--showed up.  This genus includes more than 50 described species, according to Wikipedia.

Another time, a spider snagged a honey bee, and freeloaders arrived just in time to chow down. "Call me anything you like but don't call me late to dinner." They bring nothing to contribute to the meal except their appetites.

So did the predators chase away the freeloader flies? No. Absolutely not. Apparently they're too tiny a morsel to eat, and the freeloaders don't eat much. (See BugGuide.net's images of them.

Happy Friday Fly Day!

If it's Friday, it must be Friday Fly Day.

The calendar crawls slowly sometime, but its numbers do not lie. 

It's Friday Fly Day, all right, which means it's a good day to post an image of a fly, this time a robber fly. 

As kids, we used to play epic battles of "cops and robbers," but neither cops nor robbers visited our family farm in Washington state.

Never saw any robber flies, either.

Several years ago, however, we noticed a robber fly in our family's pollinator garden in Vacaville.

With its bristly moustache, huge eyes and solid stare, it looked absolutely menacing. This is Mallophora sp., as identified by robber (assassin) fly expert Charlotte H. E. Alberts, a UC Davis doctoral candidate who studies these insects.

Scientists tell is that it's an aggressive predator known for its speed, strength, and power. The robber fly lies in wait and ambushes flying insects, including honey bees, syrphid flies,  grasshoppers, dragonflies, damsel flies and others--many larger than it is. It stabs its prey with its short, powerful proboscis, injects a paralyzing toxin that liquifies the insides, and then sucks out the content.

Probably not something you want to think about too much, right? (Check YouTube)

These insects, found throughout much of the world (there are more than 7000 species in the robber family Asilidae), can be as long as two inches and as short as 0.2 inches. 

If you look on BugGuide.Net, you can see robber flies attacking other insects, including syrphids or flower flies. 

It was the robber fly's bristly moustache, though, that fascinated us. Actually it's called a mystax, derived from the Greek mystakos, which mean "moustache" or "upper lip." Perhaps the mystax provides the robber fly with some head and face protection from stinging honey bees in their own version of "cops and robbers."

Happy Friday Fly Day!