BEND, OR -- Central Oregonians have had their share of insect invasions this year, tortoiseshell butterflies, pandora moths, cicadas, and now cicada killer wasps. Retired Entomology Professor from OSU, Ralph Berry, says these wasps infest wherever cicadas have settled, because the females need them for their larvae. "The females provision their nests with the cicadas, and they tend to be coordinated. In other words, the cicada killers come out about the same time as the adult cicadas." Berry says the wasps have 2 inch long bodies, and are more than a match for the cicadas, those small winged insects who click and buzz during the summer months. "She catches the cicada in the air, stings it and immobilizes it, carries it back to her nest, takes it down into the burrow that she's built."
For every 3 cicadas the wasp captures, she will lay 1 egg. She buries them together in sandy soil, and the larvae will eat the paralyzed cicadas throughout the long winter. "The female catches the cicadas, stings them with the venom, and it doesn't kill them, it just immobilizes the cicadas, then the wasp takes them bak to a nest in the soil." Berry says seeing the wasps prey on the cicadas is fascinating, and best of all, completely harmless for humans.
Central Oregon has an ideal climate and soil conditions for the cicada killer. "They are now digging burrows in particularly sandy soils, and this country's perfect for the females to dig a burrow and about, usually, 8-10" deep, it's pretty deep." The larvae then have food for the long winter. "And so the cicadas are alive in the nest, and they continue to be alive. If they died, they would just decay and the wasp larvae wouldn't have anything to eat."
Berry suggests leaving any cicadas or wasps you see alone.