Wednesday, April 17, 2024

The 2024 Cicadapocalypse

a cicada brood map showing in which year cicada broods will emerge in the USA

2024 is set to see the emergence of two large periodical cicada broods. Both Brood XIX (13-year cicada) and Brood XIII (17-year cicada), are expected to emerge together in 2024 for the first time since 1803. This double emergence has been nicknamed a "cicada-geddon" by some.

Periodical cicadas are native to eastern North America. They spend most of their lives underground as nymphs, feeding on tree root fluids. Depending on the species, they live either 13 or 17 years underground before emerging as adults. As adults periodical cicadas emerge in massive groups called broods. Nearly all the individuals in a brood emerge above ground within a few weeks of each other.

Axios has created a mapped timeline to visualize in which year and where in the USA each of the 13-year cicada and 17-year will emerge and in which year there will be a double emergence. In this visualization a map of the eastern USA is encompassed by two time wheels (a 13-year and 17-year time wheel). Select a year on this map and the two time wheels rotate to show you which broods (if any) will emerge that year.

The Axios article Is 2024 the Cicadapocalypse or a Cicadapalooza? also includes an interactive map which allows you to enter a city in the eastern USA to see in which years the city will experience a cicada brood emergence. 

map showing past sightings of cicada broods
According to the University Of Connecticut's overview of the 2024 Periodical Cicada Emergence, although both Brood XIX and Brood XIII will emerge in 2024 they will "not overlap to any significant extent." 

The university has mapped out past positive presence records of both Brood XIX and Brood XIII. On this map positive presence records of Brood XIII are represented by images of upwards facing cicadas and positive presence records of Brood XIX are represented by images of downwards facing cicadas. The map allows you to see where the two broods have emerged in previous years.

The university also says that even if both broods do emerge in the same area there probably won't be a higher density of cicadas than if only one brood emerged, because "Competition for resources (e.g., food, space, or ovipisition sites) is expected to impose an upper limit on cicada densities".

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