Cicadas – not just Brood X!

Chances are you’ve seen internet articles about the mass cicada emergences that’ll be happening across the eastern United States this year. Here’s a decent writeup from the National Park Service.

Periodical cicadas are named for the long stretches of time between their emergences (13 or 17 years, depending on the lineage). The thought is that this makes them an unreliable source of food for predators – it’s hard to be a specialist wasp if your food species vanishes and is unaccessible below ground for over a decade at a time.

And, when you emerge, surrounded by thousands of others like you, it’s statistically unlikely that you’ll be the one who gets eaten – be it by bird, dog, or unattended small child. Though many of your kin will be devoured, you’ll probably be safe. It’s the same tactic the now-extinct Passenger Pigeon used. Passenger Pigeons built undefended nests on the ground, and relied on numbers to make any individuals odds of survival better. A tactic that worked excellently until it didn’t.

While we don’t have periodical cicadas (genus Magicicada) this far west, we do have other types of cicadas, especially genus Okanagana. I’ve been hearing their males sing in the trees on my drive back from work over the past couple of weeks. One way cicadas avoid predators is by being active in the sweltering heat when nothing wants to hunt. Cicadas cope with the heat by drinking tree sap nearly constantly, and releasing excess moisture through pores in their thoraxes, much like how we humans sweat to cool down.

Our cicadas here have life cycles maxing out in the 3-year range. As such, these species can be pretty reliable hosts for certain predators, like the cicada killer wasp… but our cicadas lead a charmed life. The Western Cicada Killer Wasp only goes as far east as Idaho, and the Eastern Cicada Killer Wasp only really goes as far west as the Dakotas.

Our local cicadas are convinced that this truly is God’s country.