20 June—Summer doesn’t officially start—the summer solstice (solstice from the Latin for the sun standing still) doesn’t occur—over Connecticut until several minutes before 11 o’clock tonight. But to celebrate it here’s a picture taken shortly before sunset yesterday by The Monitor’s ace entomological photographer of the first firefly of summer resting up on a window before lighting up the life of his sweetheart at night. (Amazing the macrophotographs phones can snap.)

It’s pretty safe to assume our photogenic firefly is a he because of the size of his light bulb and because most female fireflies wouldn’t alight on windows because they don’t fly.

There are some 2,400 species of fireflies, also known as lightning bugs and glowworms. They’re actually beetles and many don’t have the ability, desire, nor need to light up for lust; they simply depend on good old-fashioned pheromones to attract sex partners. Some oversexed ones use both pheromones and light.

Fireflies produce light by bioluminscence, a chemical reaction of oxygen, calcium, adenosine triphosphate, and luciferin—in the presence of the enzyme luciferase, to be sure. It’s cold light, of course, with virtually no energy being lost as heat, lest the little bugs be fried by their insatiable lust.

The clever little bugs switch their lamps on and off by controlling the flow of oxygen to the other chemicals in their lust lanterns. No surprise that Viagra plays a part in firefly flash control. Kind of, anyway: Fireflies produce nitric oxide gas (not to be confused with nitrous oxide, also known as laughing gas) to turn on their lanterns and one another and cut the gas off as the mood or endurance may require. Actually, nitric oxide breaks down pretty quickly anyway, so the cold flashes don’t last all that long. And, as it happens, Viagra (sildenafil citrate) produces nitric oxide to dilate penile and other blood vessels and thereby enhance erections . . .