Surviving Cicada Season – Nice Ecology

September sixth, 2024

Surviving Cicada Season

Writer: Liz Hartel, MS

Let’s speak about cicadas. With over 3,000 species, cicadas are a typical summertime prevalence for a lot of the world. Most cicada species are annual cicadas, which means they emerge at numerous instances all through the summer season yearly. Within the US, there are additionally seven species of periodical cicadas who’ve developed the distinctive evolutionary trait of rising unexpectedly each 13 or 17 years.

As you’ll have heard, 2024 was particular for cicadas – the US noticed a double emergence of adjoining broods of periodical cicadas. Brood XIX (aka the Nice Southern Brood) is a 13-year brood stretching throughout the Midwest and Southern US (from Missouri by means of the Carolinas). Its neighbor, Brood XIII (aka the Northern Illinois Brood) is a 17-year brood spanning northern Illinois and japanese Iowa. These explicit broods sync up as soon as each 221 years – making this really a as soon as in a lifetime expertise.

Now, expensive reader, you may be questioning why I’m invested in cicadas. In spite of everything, I’m not a typical cicada predator (though some individuals do eat cicadas). So let me let you know a bit extra about my private expertise with the 2024 emergence, and why cicadas are so fascinating.

Final yr, I moved to St Louis, MO – which is throughout the vary of Brood XIX. That is my first time witnessing a periodical emergence, and I can truthfully say I’ve by no means skilled something prefer it.

Periodical emergence is a vital ecological occasion – each for cicada species and for predators. Cicadas are clumsy fliers with no energetic protection mechanisms (camouflage, flying away, and screeching are about it). Predators embody birds, bears, fish, raccoons – mainly something that eats bugs will eat cicadas. Even considered one of my indoor cats (appropriately named Gremlin) thinks they’re scrumptious. By rising unexpectedly, periodical cicadas flood the realm with so many tasty cicadas that it’s inconceivable for predators to eat all of them – thereby making certain the survival of many of the brood. In flip, predators get an all you possibly can eat buffet. Lovely child raccoons (or ABRs as my husband calls them) returned to our yard a number of instances to feast on this buffet.

There’s no ecological unfavourable to cicada emergence. Not like many different bugs, they don’t trigger harm to crops or property. Small timber and shrubs can face slight impacts if too many feed on their sap or lay eggs in them, however bigger timber are fully unfazed. Small timber might be simply protected by putting a nice mesh web over them throughout emergence. Cicadas additionally don’t chunk or sting (though their grippy ft really feel just a little uncomfortable on the pores and skin) and are non-toxic so that you don’t have to fret an excessive amount of about pets. Nevertheless, pets with no self-control (like my cat Gremlin) may eat too many and provides themselves a tummy ache if left unsupervised.

The lifecycle of periodical cicadas is an attention-grabbing one. They spend most of their lives underground, within the nymph stage, feeding on root sap. After 13 or 17 years (relying on species), they emerge in April-Could when soil temperatures attain roughly 64°F. In St Louis, in early Could we began to see a number of cicadas right here and there. Inside 5 days, they had been out of the blue in all places – masking tree trunks, the edges of homes, and swarming by means of treetops.

However how do cicadas know when to emerge? Scientists imagine they use the basis sap to trace the expansion cycle of the timber they feed on. When timber bud within the spring, the sap briefly incorporates extra amino acids; cicadas use this alteration to rely the variety of springs which have handed. Then, when its time, cicada nymphs emerge from the bottom and crawl up the closest vertical floor to molt. The winged adults then clumsily fly round, drink sap from woody shrubs or timber, and search for mates. The males screech out their mating name, typically banding along with different males to kind a refrain. In St Louis, by Could 18^th the cicadas bought so loud we wore listening to safety after we walked our cats outdoors (sure, we stroll our cats on leash).

One other distinguished factor the adults do is urinate – as much as 10 ft per second! The sap cicadas feed on is low in vitamins, however excessive in water content material – which means they devour A LOT of fluid. Due to their digestive system, cicadas course of fluid at 300 instances their physique weight and urinate in a jet stream. It’s so frequent, it has a nickname – “cicada rain.” Between the noise, cicadas flying into my hair, and getting peed on by cicadas, being outdoors was fairly disagreeable by late Could.

After mating, a feminine lay her eggs in a groove she makes in a tree limb. Then the adults die en masse, leaving the faint stench of dying lingering within the air (in St Louis, this began to occur round June 1^st). Fortunately, the odor wasn’t overwhelming like decomposing mammals, however extra harking back to fertilizer utilized in crop fields – probably as a result of useless cicadas are chock stuffed with nitrogen (the principle ingredient in most fertilizers). That is simply one other instance of how cicadas are a boon for the setting – ending their lives as nutrient-rich plant meals for forest soil, gardens, timber, lawns, and wildflowers. Later, when the eggs hatch, nymphs will feed on the uncovered sap after which finally drop to the bottom and burrow close to the bottom of the tree – and the cycle begins once more. All-in-all, periodical cicadas are above floor for roughly one month of their lives. And should you had only one month to reside above floor, would you actually reside it any in another way?