Have you noticed the Cicadas Cacophony slowly growing in our beautiful Blue Mountains region of late? Well brace yourself cicada enthusiasts, this summer’s emergence is tipped to be a big one in the blue mountains! Spring has already offered a glimpse of what’s in store, and it’s been wild: Tree trunks covered in empty shells and the deafening roar of thousands of the world’s loudest insect. For many, cicadas are the quintessential soundtrack of an Australian summer, and conjure sunny days spent seeking a rare Blue Moon, or the common Green Grocers. Even their names are a hangover of the 1970s and ‘80s, including the oversized Double Drummer, ear-piercing Razor Grinder, handsome Black Prince, tipsy Red Nose, musical Golden Twanger, playful Beach Squeaker, and dreaded Alarm Clock Squawker!
Cicadas are found across the globe, but Australia is their unofficial headquarters. With over 350 species identified (but likely over 1000 species domestically), we have the richest diversity of anywhere on the planet. However, they are not well understood. They spend the majority of their lives underground and out of sight, following cycles far longer than the traditional 3-year timeframe for a PhD, so most research is performed by amateur enthusiasts. In the US, Magicicadas are famed for their periodical emergence. Some burst from the ground every 13 years, others every 17 years. They emerge so reliably ecologists have mapped and split the groups into different “broods” and know which year each one will materialise.
Our most common variety, the Green Grocer, lives a 7 year cycle, with adulthood only lasting a few weeks. Females are silent (and possibly hard of hearing!), laying their eggs using a special spike that neatly penetrates slits made in a plant stem. The eggs hatch as small, wingless nymphs that fall to the ground and burrow into the soil. Armed with sucking mouthparts, they harvest sap from the tree roots, shedding their skin as they grow. The nymphs eventually use their large front legs to dig their way out of the soil and up onto tree trunks. Like a scene out of Alien, the final moult occurs as the topside of the skin splits open to reveal the adult, winged cicada.
Cicadas don’t sting, bite, or have many defensive tactics, however their cacophony of sound is thought to confuse predatory birds. Their boom and bust breeding strategy tips the numbers in their favour. Plenty get eaten by birds, insectivorous mammals and tree climbing reptiles, but by overwhelming even their most voracious predators, they ensure plenty of fertile cicadas survive long enough to breed.
According to cicada expert Professor David Emery as quoted in the Sydney Morning Herald, the blue mountains brood of Masked Devils, a colour variant of Green Grocers, started their emergence exactly 7 years to the day of their last mass appearance in September 2017. The exact triggers for emergence are unknown, so if you would like to contribute to our knowledge base of cicadas you can sign into the Great Cicada Blitz, where people record calls and upload sightings to generate data about when mass emergences occur. The numbers collected will be used to model weather data to see if there are climatic triggers that affect the time and location of their appearance. Apart from a cacophony of cicadas, you will be serenaded by birds, frogs, gliders and possums when you come and stay at Wildside Sanctuary. Choose from The Bower eco cottage or Frog Hollow nature escape for your magical weekend. Explore local trails, ride our complimentary bikes, try fruit picking, gin tasting or cider sampling at local Bilpin orchards. Book direct through our website and save.
