Big wasps By Shauna Dobbie
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ikes! What’s that? As a gardener, you thought you’d seen everything, but suddenly, you’re looking at a huge flying creature you swear you’ve never seen before. It could be a wasp, but don’t worry; it probably doesn’t sting. Here is a selection of the biggest wasps in Canada to help you identify that thing that gave you a heart attack. Asian giant hornet (Vespa mandarinia). The stuff of which nightmares are made. Well, along with media reports of “murder hornets”. The Asian giant hornets are far more likely to murder honeybees than people. Queens can be 2 inches long and workers tend to be around 1.5 inches. The stinger alone can be a full ¼ inch long, four times as long as a honeybee stinger. They prefer forests or green spaces to live in, and in the past, they were found only in Asia. For the last three summers, they’ve been found in the Vancouver area. Canadian and American authorities have been doing their best to eradicate them. If the insects get a foothold in North America, they could decimate honeybee populations. One hornet can decapitate 40 honeybees per minute by biting their heads off. Asian giant hornets can kill a person who is not allergic, but at least 30 stings are usually required. In Canada, the hornet hasn’t been found outside the Lower Mainland of BC. Cicada killer (Sphecius speciosus). A kind of yellow and black wasp found only in the southern fringes of Eastern Canada, the cicada killer is often mistaken for a murder hornet because of its size of up to 2 inches. It isn’t interested in humans though; its target is cicadas. The female brings a cicada back to her nest and lays an egg on it. When the egg hatches, the larva eats the cicada. Cicada killers have stingers and can sting you, but they probably won’t. 18 • 2021
The “killer hornet” got its name for killing honeybees, not humans.
Mud dauber preparing a ball of mud to grasp for flight.
Giant ichneumon wasps (Megarhyssa). There are a few species of these across Canada, but most have a body about 1.5 inches long with an alarming-looking spike of 2 inches or longer coming out the back of the females. People get upset upon seeing this because they think it’s a stinger. It isn’t, it’s an ovipositor—an egg-layer. Ichneumon wasps lay eggs onto or into other living insects or caterpillars; when the eggs hatch, they Issue 1
eat their host. Once you understand that the giant ichneumon wasp can’t hurt you, it’s fascinating to watch one flit from flower to flower, sipping nectar. Black and yellow mud dauber (Sceliphron caementarium). This wasp is incredible to watch for how it builds homes for its eggs: they gather mud to form the structures. Each egg gets a pretty big room because it is otherwise stuffed with localgardener.net
