Bugging Bugs--Safely
I have a very environmentally conscious friend in Hawaii. She recycles everything she can; she treads carefully when she walks in the woods; she eats a lot of whole grains and very little meat. And far in the back of her undersink cabinet she keeps a can of lethal, do-not-breathe-ever insecticide. It's like a skeleton in her closet, for more reasons than the small skull and crossbones symbol she's pasted on it.
"I hate the stuff," she said. "But it works. And this is cockroach country. They'd carry me off if I didn't use it, or something just as awful."
In some ways Alaskans are better off than Hawaiians. If we're a bit careless with our garbage, we're more likely to draw bears than cockroaches. Still, we must deal with some invading and unwelcome creepy-crawlies in homes and camps. I too have a can of awful stuff I hate to use--but when the carpenter ants come marching in, I use it.
There may now be a product for people who'd like to keep the bugs at bay without poisoning the environment--or themselves. Its inception came in tragedy: a little boy in Pennsylvania thought a can of insecticide was breath freshener, and sprayed some into his mouth. The child died. Inventor Dorsey Dunlap was a friend of the boy's family, and he set to work on developing an effective but nontoxic insecticide.
It took twenty years and the help of University of Pennsylvania entomologist Robert Snetsinger, but Dunlap thinks he's done it. The secret of the product's safety lies in the developers' recognition of exactly how unwanted pests differ from you and me (and our pets, for that matter). Roaches, ants, termites, spiders, silverfish and such are all arthropods. They have exoskeletons--in effect, they're given structure by armor on the outside rather than a framework on the inside.
Typical insecticides kill pests by attacking their nervous system. The nervous systems of birds, fish, and mammals are different, but not that different; that's why ordinary insecticides are dangerous. Dunlap's product doesn't affect the nerves, digestion, or respiration of anything--even the pests it kills. What it does do is poke tiny holes in their protective exoskeletons. They lose fluid through the holes and dehydrate to death.
Something that perforates an exoskeleton sounds at first as if it would also be dangerous--what might it do to puny human skin? It's not. The main ingredient in the new insecticide, called Shellshock by its inventors, is diatomaceous earth. That's a substance already in common use, in products as diverse as cat litter and toothpaste. It's safe, abrasive, and absorbent.
It's also a natural product, if a rather elderly one. Diatoms are the original creatures living in glass houses. They're tiny marine algae--phytoplankton--that protect themselves within spiky shells of silicon dioxide. Millions upon millions of those shells build up on the bottoms of sea and lake beds. Diatomaceous earth is now mined from what were once the beds of ancient waterbodies.
When an insect wanders through a dusting of Shellshock powder, the jagged particles of old diatom shells punch through its exoskeleton. Inert ingredients mixed with the diatomaceous earth make it more sticky; it can't be shaken or groomed off. The powder particles begin to absorb the insect's fluids. It's doomed.
Or so I've read. I've yet to see a bottle of Shellshock on a store shelf, much less try it out--so please don't take the foregoing as a sales pitch for the stuff. If I see it, I'll certainly try it--if only to honor the original and creative thinking of an inventor and a scientist. They're still at it, by the way: under development now is an insect repellent, the sort of thing you could spread around doorsills to keep bugs from sneaking in. This one too is guaranteed safe for people, pets, and wildlife. Its active ingredient is orange-peel oil.
