In her 17 years working as an extension entomologist in Eastern Oregon, Silvia Rondon has never received more reports, emails, phone calls and texts with questions asking what type of wasp they just saw.
After the Asian giant hornet showed up in Washington last year, many Oregonians have been on alert. However, experts such as Rondon want you to know the wasp you come across is more than likely a cicada killer wasp — which is fairly harmless to humans and pets.
“This insect, unless you’re messing with them and trying to touch them, they shouldn’t be a bother. They are a nuisance, and they’re impressive, because they’re very large,” said Rondon.
Cicada killer wasps are native to Oregon and emerge during summer. They live 60 to 75 days before they migrate back underground until the next year. Oregonians can expect to see the insect until September.
Hot spots for the wasps are primarily in Central and Eastern Oregon. Rondon said about 70% of her calls come from the Pendleton area.
Jim LaBonte, a retired entomologist from the state Department of Agriculture’s insect pest prevention and management program, said Eastern Oregon makes a suitable habitat for the wasps as the area is blanketed with sandy soil and trees — an environment in which the wasps can dig their underground nests with ease.
But for the most part, the cicada killer wasp is harmless toward humans, he said. Their prey is another insect — the cicada.
The female wasp paralyzes a cicada with one sting and then drags the insect back to its hole, which is dug 10 inches below the surface of the soil. Sometimes, this can be an all-day endeavor.
Once inside the nest, the wasp will dump the cicada into a side chamber and lay eggs. As the eggs hatch, starved larvae eat the cicada alive — which could take weeks, LaBonte said.
The male wasps keep themselves busy by fighting for a mate and vomiting on their own heads to stay cool in the summer heat.
They may sting humans or pets if they feel threatened, such as if they are stepped on or their underground burrow is disturbed.
“If you disturb their nest, they’ll get a little agitated,” said Tracy Wilson, agricultural literacy coordinator at Oregon State University, but the wasps are solitary by nature, so you probably will not see a swarm of them, decreasing the risk factor.
People in agriculture or who have home gardens shouldn’t worry either; they only cause minimal landscaping damage as the wasp digs into the ground to create a nest for its eggs.
There are a few differences between the two wasps. Asian giant hornets are larger, about 2 inches long, and have unbroken bands of yellow and brown across their abdomen.
The cicada killer wasp has three large stripes of yellow and black around it, and are about 1 to 1½ inches long and have a long stinger.
There have been no traces of the Asian giant hornet in Oregon.
Wilson said people can send samples or photographs their way if they can’t tell the difference. This will help ease the worry and help the ODA track the wasps.
Though Asian giant hornets are not a worry for Oregonians, Rondon, the entomologist, does have one bit of advice for anyone who comes across a cicada killer wasp: “In general, stay away from them.”