By Mark VanderWerp
To view this article as it appeared in PCT magazine, click here.
Advertising is all around us — billboards on the side of the road, commercials on television or manufacturers’ ads in PCT. They’re quick and catchy, attention-grabbing message delivery vehicles. Just like the “advertisement” coloring of a yellowjacket. Wait, what?
You may not have realized that many insects are in advertising, too! Oftentimes, brightly colored animals are trying to warn predators that they are noxious or dangerous in some way; they may taste bad or deliver a potent sting. If you abuse an arthropod with warning coloration, the bright color and the unfortunate experience work together to make sure that the critter’s message is delivered and understood, “Do not mess with me or my species!” In fact, their ad campaigns are so effective that other arthropods may copy their “tagline” through mimicry (even when the knockoff doesn’t have the stinger to back up the claim), but this is a different topic for a different day.
The Real Danger in a Sting. Arthropod toxins are amazing substances that have been specifically honed over evolutionary time to shock our systems and are, drop for drop, some of the most deadly substances on the planet. It’s really no surprise; if you’re a half-inch long wasp and you want to deter a 6-foot tall “predator” by intimidation, you’d better have some pretty potent firepower in your arsenal. And they do! Stinging insects cause many people to cower in fear at the mere buzzing of a large insect near them, lest it be a ferocious wasp undoubtedly out for blood. Wasps have us so well trained that people forget that we are the aggressors in the scenario and the puny insect is the underdog. The Hollywood analogy to this is a measly human deterring King Kong with a rocket launcher. You wouldn’t root for the poor, ole gorilla that is being picked on by menacing humans, would you?
So, just how potent are insect stings? Researcher Dr. Justin Schmidt has dedicated much of his career, as well as his bodily comfort, to better understanding hymenoptera (wasp, ant and bee) stings. Schmidt has measured the LD50 value for many common hymenoptera, and reports the venom of the German yellowjacket, Vespula germanica, an insect regularly encountered in the pest management profession, to be 2.8 mg/kg. (Many of us don’t measure things in kilograms, and we certainly don’t measure them in milligrams. As a quick refresher, a kilogram is a unit of weight about equal to 2.2 pounds while a milligram is a minute mass, smaller than we are used to handling. Pull some change out of your pocket and find a dime — it’s the lightest coin in U.S. currency and weighs about 2,250 milligrams.)
Using the mental comparison of the fractional weight of a dime vs. a 2.2-pound weight, let’s take another look at the LD50 of yellowjacket venom. Remember that an LD50 indicates the amount of a substance required to kill 50 percent of the individuals who receive the dose. If we do the math and calculate how much yellowjacket venom is required to wring the life out of an average 150-pound (68 kg) technician — working without proper PPE (and for a competitor, of course) — we arrive at about 0.2 mL of venom — or 4 drops. Drip, drip, drip, drip and dead. Now that is potent delivery for a wasp’s brightly colored advertising! Luckily, each individual wasp is not packing too much heat. To reach this amount of venom, one would need to be stung by about 3,000 yellowjackets. Of course, if a person is allergic to the proteins in the venom and goes into anaphylactic shock, one sting may be all that it takes.
By comparison, a residual pyrethroid pesticide, which could be used to kill German yellowjackets, will likely have an acute oral LD50 value somewhere around 2,000 mg/kg. If one wanted to finish off the unfortunate technician from the previous example with this pesticide, about 6 pounds of an undiluted product, straight out of the bottle, would have to be ingested. This would be awfully close to three-quarters of a gallon.
Final Thoughts. OK, no more numbers-based scenarios and fuzzy math! Certainly venom being injected directly into the blood stream is different than a pesticide being imbibed, but hopefully these examples give a rough sense of scale of the difference in acute hazard that insect venom (and pyrethroids) pose. Now we just have to make sure that we can convey this difference to our clients.
The benefits of properly used pesticides in and around the home can far outweigh the risks posed by the pesticide and other hazards already present on the property. So, tell your clients how valuable and low risk your services can be (and make sure that they are). Perhaps, as pest management professionals, we will have to be more comfortable when it comes to advertising, too, and unabashedly tell the public what we have to offer.
The author is manager of education and training, Rose Pest Solutions, Troy, Mich.