Is nothing sacred? Now it turns out moths aren't always drawn to a flame
I was thumbing through the most recent issue of the Journal of Insect Conservation (what, you don’t subscribe?) and I came across an interesting article that notes the declining number of moths scientists are able to capture in light traps.
Light traps are what they sound like. Scientists, on a moonless night, shine a light and record the insects that are drawn to it, almost “like moths to a flame,” you might say.
The gripping account of scientific moth-counting is not without drama. A scientist named Dan broke three ribs “jumping into a ravine” at the Costa Rica jungle laboratory. This is real Indiana Jones stuff, and to a non-science person like me, the most interesting, or at least comprehensible, part of the report.
Unfortunately, scientists do a poor job of media adaptations, so we never hear another peep about it, or learn why Dan was jumping into a ravine. Was Dan chasing something, or more terrifying, was something chasing Dan? Or is Ravine Jumping just some sort of jungle game scientists play to pass the time when they’re not rinsing out test tubes? We will never know.
What we do know, because the report states it, is that “Since terrestrial arthropods as a whole are the great middle bulk of all terrestrial eukaryote food and interaction webs, their reduction, by whatever means, is to gut the terrestrial planet.”
I take this to mean that bugs are important.
Indeed, there are 5,400 species of mammals on earth, 11,000 species of birds and 18,000 species of butterflies.. But there are 160,000 species of moths.
So the question became, with so many moths wandering around, why were they not showing up in the light traps? One theory is that this could be part of the “insect apocalypse” attributable to climate change.
Another thought is that moths simply might not be as attracted to light as they once were.
According to The New York Times, Charles Darwin was once asked about moths’ weird fascination with light. His answer was a surprising, “They’ll get over it.”
Moths had been around for a long time before artificial light, so when gas lighting became common on London streets they said, “Hey, what’s all this bright stuff? We better go check it out.”
“Darwin was like, ‘Very true, maybe it’s because lights are quite new and moths haven’t quite figured it out yet,’” Avalon Owens, an entomologist at Harvard told the Times. “But you might expect that over time they will stop doing this. He literally put that out there 150 years ago, and everybody just sort of forgot.”
So are there fewer moths, or are they just not that into light anymore?
To put it to the test, researchers set up a pheromone trap for corn earworm moths next to a light trap and noticed that, by comparison, light traps are attracting fewer and fewer moths. “It might be, as Darwin suggested,” the Times says, “that evolution has removed moths with an attraction to light from the gene pool, so that today’s corn earworm moth is no longer as drawn to light.”
It just took time. It stands to reason that moth brains are not as large as humans’. So where humans might have gone to investigate an unfamiliar light source and found it to be harmless, it would have taken five minutes before they said, “It’s nothing, Edna, go back to bed.”
But for a moth, it’s taken 200 years.
Now it would be easy to scoff and point fingers at the moths for taking so long to figure it out, but come on. They’re moths. I think it’s pretty impressive. “Light is no big deal” could be the E = mc2 of the moth world.
Not all insects have gotten the message, obviously, since we still see them around porch lights. These are the “light is OK” deniers who refuse to believe the science.
It’s a free country. But they will be the ones that get zapped.
Trump Media stock has tanked. What will that mean to the investors who put faith in DJT?
Tim Rowland is a Herald-Mail columnist.
This article originally appeared on The Herald-Mail: Hold off on that bug zapper: Studies show bugs aren't that into light
