Several years ago, I made my peace with insects, but it lacked a Mahatma Gandhi or Albert Schweitzer-like reverence for life. It was simple math. Sources suggest there are 200 million insects for each human on the planet.
The New York Times speculated that, worldwide, there are 300 pounds of insects for every pound of humans.
It is estimated that there are 10 quintillion (that’s 10 with 18 zeros) insects alive.
My peace with insects is directly related to the fact that we are outnumbered.
Perhaps that’s why Whitney Cranshaw autographed “The Ultimate Guide to Backyard Bugs and Garden Insects of North America” to me with the cheerful reminder, “Bugs Rule.”
“Quintillion” was what came to mind when I saw onion thrips (Thrips tabaci) feasting on my baby onions. Pursuing the fatuous advice that “to know them is to love them,” I reviewed what I knew about thrips. We notice the thrips when they appear and feed in their first and second instars (stages between molts), having hatched shortly before from tiny eggs deposited in the stem of a plant. They feed only during these stages. But they get wildly interesting (remember: to know is to love) in the remaining instars.
Inactive and not eating, in the third and fourth instars, they develop strap-like fringed wings, which give the name to their order — Thysanoptera, which means fringe wing.
The fascination grows. They, like many other insects, can use their hemolymphatic (body fluid) pressure to turn their little footpads inside out so they can walk on vertical surfaces. To discourage predators, they secrete a trail from their hindgut.
Their development and behavior fascinates. But it is the sexual activity of these plant suckers and onion attackers, shared by some ants, bees, beetles and spider mites, that is worthy of note in fact and in vocabulary.
The sex of the thrips is determined by the haplodiploid sex-determination system. In an explanation reminiscent of the old song, “I’m My Own Grandpa,” one source describes part of this system, “An offspring formed from the union of a sperm and an egg develops as a female, and unfertilized egg develops as a male and is haploid with half the number of chromosomes of a female. … This system produces a number of peculiarities; chief among these is that a male has no father and cannot have sons, but he has a grandfather and can have grandsons.”
It was the Swedish botanist Carl Linnaeus who officially named the creature thrips in 1758. And he used a collective noun! One thrips. Quintillion thrips!
I try to know them and appreciate their oddities, but alas! I will never love them. I’ll take Cranshaw’s word; they may rule, but only briefly, because I intend to terminate their lives at their second instar on my onions.
Cathie Draine is a member of the South Dakota State University Cooperative Extension Master Gardeners and the Garden Writers’ Association. She lives and gardens in Black Hawk. Contact her at firstname.lastname@example.org.