Our area is hosting one of the great spectacles of nature…the return of “Brood X”, the cicadas. It’s a phenomenon that, depending on the species, only occurs every 13-17 years, but, for most, is memorable. Do you remember their last appearance in 2004? Magicicada, the genus including seven species of periodical cicadas, emerge from the ground after spending 12-16 years as juveniles sucking nutrients from tree roots and growing from the size of a small ant to their adult size. The purpose of this emergence is to mate, create a new generation and, sadly, die…all within a few weeks’ time.
The ‘song’ that is music to some and annoying noise to others (most?) is primarily a mating call that male cicadas emit after burrowing from the ground and climbing a nearby tree. For their short life above ground, the tree will provide a source of food for the adult cicadas as well as a place for the females to carve out little ‘cradles’ in which to lay their nearly 600 eggs…assuming they are not eaten before they get a chance to do so.
Why does this happen only every 13-17 years? Likely it is a survival strategy. In areas where the broods emerge, they can number tens to hundreds of thousands per acre. Their numbers are their greatest defense mechanism as they are not great flyers and don’t bite or sting. Many will be eaten by a variety of other animals including: insects, reptiles, birds, and mammals, including squirrels, fox and…yes!…your dog. At some point though, even those critters will have had their fill and the predation will lessen precipitously. Clever strategy!
After about 4-6 weeks, the cicada nymphs will emerge from the eggs and drop to the ground in order to burrow underground to find a tree root to feed from for the next 12-16 years, beginning the cycle again. So, you might ask, why? What ecosystem services do the Magicicada provide? The most obvious might be the tremendous boost to food supplies, which leads to increased populations and healthier young for many animals, including many bird species in the year(s) following an emergence. The bodies of the dead adults also create a significant boost to nutrient levels in the soil, benefiting plant life. Are you interested in helping scientists analyze the activities of Brood X, 2021? Where are they emerging? Are there locations where they are no longer appearing (local extinction)? The Cicada Safari, an app, can be downloaded to your smartphone in order for you to upload photos of cicadas you find. Check out CicadaMania.com for more amazing facts about these fascinating insects!
Written by Lisa Herman, FCW Board Member