Theoretically, it takes A LOT of wasp venom to kill a man – studies estimate that a lethal dose is approximately 10 stings/pound for most mammals – but in many cases, people die after far fewer. Such is the tragic case of La Prairie mayor Lucie F. Roussel, who died last month after being stung by an estimated 15 wasps while at her summer cabin in Stratford, Que. 51-year-old Roussel was doing yard work near her lakeside cottage when she inadvertently stepped on a wasps’ nest and was stung multiple times by the angry swarm. Although she had no known allergic reactions to wasp venom, and doctors say it is extremely uncommon for someone to die as a result of insect stings directly, it could be possible for the amount of venom she received to kill someone with an underlying health condition.
Although deaths from venomous insect stings are still very rare in Canada – according to Statistics Canada, 40 people died from bee, wasp, or hornet stings between 1999 and 2011, with an average of 3.3 Canadians/year – life-threatening, allergic reactions from insect bites are on the rise. Health Canada estimates that approximately 600,000 Canadians are at risk of dying from severe allergic reactions (anaphylaxis) caused by insect venom, foods, and other triggers, and the numbers are growing especially among children.
Most people know when they’ve been stung by wasps due to the excruciating pain they feel – much more intense than that delivered by bees and ants. In fact, University of Arizona entomologist Justin Schmidt, who let himself be stung by 150 different insects in the name of science, said that a paper wasp sting felt like “spilling a beaker of hydrochloric acid on a paper cut,” rating it 3.0 on a scale from 0 to 4. The only two stings more painful than a wasp’s were delivered by the tarantula hawk (4.0) and the bullet ant (4+), which can last up to 24 hours.
In the case of wasp venom, the intense pain is an exaggeration of the physical damage, which is typically minimal, and it’s the wasp’s way of informing its predators that, despite its small dimensions, it is capable of dishing out considerable physical damage. The exact chemical composition of wasp and bee venom is not entirely known, but it is believed to contain a complicated cocktail of peptides, enzymes, and proteins that, once injected through the stinger into the victim’s bloodstream, they start attacking cell membranes in the blood. If the injured cells happen to be neurons, a signal is then sent to the brain, informing it of the existing threat – signal which we experience in the form of pain.
To ensure a prolonged pain sensation, other adrenergic substances in the venom, such as noradrenaline (a powerful blood vessel constrictor), stop the flow of blood to the affected cells, which is why we feel the same excruciating pain for several minutes (until the venom is carried away and the blood circulation to the cells can be restored). Finally, the enzyme called hyaluronidase starts breaking down the hyaluronic acid, substance found in the extracellular construction of nearly all tissues in the human body, responsible for connecting protein filament, collagen fibers, and the connective tissue cell. After the insect sting, hyaluronidase degrades the extracellular matrix and connective tissue between cells, causing the inflammation and redness commonly associated with bee and wasp stings.
Most of the times, wasps will not launch a direct attack on you (not even the most aggressive species) unless they feel their nest is threatened. If they’re just buzzing around you or flying around your garden, chances are they are only looking for flowers or insects to feed their larvae. Since you are neither a flower nor an insect, you don’t have to worry too much. Here’s how to make sure you’re not mistaken by either of those things:
Sometimes, wasps establish their nests in inconvenient places, or their colonies become too large to continue sharing the same space with humans, especially if they reside in the close proximity of people with severe allergies. In such cases when wasps turn from beneficial components of your garden ecosystem into dangerous pests, professional pest control is needed to ensure the management and safe removal of all existing colonies.
About the Author
Daniel Mackie, co-owner of Greenleaf Pest Control, is a Toronto pest control expert well-known as an industry go-to guy, an innovator of safe, effective pest control solutions, and is a regular guest on HGTV. Mackie, along with business partner Sandy Costa, were the first pest control professionals in Canada to use detection dogs and thermal remediation for the successful eradication of bed bugs. In his free time, he is an avid gardener.