They are the unmistakable sound of summer and this year one of Australia's foremost cicada experts wants you to photograph the noisy creatures as he continues to document their broad diversity in Australia.

Key points: Members of the public are being encouraged to submit their cicada photos for an updated book profiling different species

Members of the public are being encouraged to submit their cicada photos for an updated book profiling different species Citizen science can help discover new species or show their distribution across the country

Citizen science can help discover new species or show their distribution across the country Australia has the largest number of cicada species in the word

You could forgive a cicada for not being up to date with current affairs — they quite literally might have been living under a rock for the last 10 years.

Each summer, cicadas emerge from a very long period underground spent feasting on grass and tree roots and make their piercing cry heard.

Cicada expert Nathan Emery said there were about 800 cicada species we know about, but that number could easily be higher if people get behind a project to photograph the species they see.

"That number could top 1,000 if we could survey more remote, arid regions in Australia," Dr Emery said.

"We only have 400 scientifically-described, so there's a lot we don't know.

Dr Emery has photographed this golden twanger cicada for his research. ( Supplied: Cicadarama/Dr Nathan Emery )

"There's a need to promote this diversity we have in Australia compared to the rest of the world."

The photographs will be used to update his book A Photo Guide to Common Cicadas of the Greater Sydney Region.

It was originally created to fill a hole in cicada resources so people could identify the insects they found by sound and appearance, but such is the sheer number of species out there, it needed updating.

In fact, Australia has the highest number of cicada species in the world and Dr Emery wants to see people's encounters with them.

"Any cicada species you come across, or if you've taken photos in previous years, from common species to less common species, I want to represent them all in the next iteration of the book," he said.

Citizen science helps track cicadas' spread

Dr Emery said photos from the public could not only lead to the identification of new species, it could also show the spread of cicadas across the country.

Last year, a photo of a rare red eyed fairy cicada in Nowra on the NSW South Coast was posted to an amateur entomologists Facebook page that caught his attention.

The species — Samaecicada subolivacae — is named after his sister, Samantha, who discovered the cicada in 2005.

Dr Nathan Emery is updating his guide to identifying cicadas. ( Supplied: Dr Nathan Emery )

"We hadn't seen or heard it in five or six years and then it came up on a social feed and I recognised it from its bright red eyes," he said.

"We had no idea it occurred down in Nowra — we knew it occurred in the Blue Mountains and Royal National Park.

"It shows how useful citizen science can be in expanding cicada distribution."

Photos from the public will also reflect the environment the cicadas live in, with many of Dr Emery's photos taken in a studio with artificial light to bring out the detail of the insect.

Love for cicadas in the blood

Dr Emery's day job is a science officer at the Australian Botanic Garden in Sydney and his father David is a Professor of Veterinary Parasitology at the University of Sydney.

While both men have pursued careers in science, their love for cicadas has often been a passion on the side which has spread through his family.

"Growing up, we'd all go out to the national parks and bushland reserves armed with butterfly nets to catch as many cicadas as we could to impress dad," Dr Emery said.

Cicadas are often named for their characteristics, such is the case with this cherry nose variety. ( Supplied: Cicadarama/Dr Nathan Emery )

"I look back on that time fondly because those occasions being out in the bush, enjoying the surrounds and witnessing the diversity of cicadas and the diversity of plants and animals got me enthusiastic about the environment and ecology."

As a child, he was especially captivated by the red-eyed cicada, which shares the same genus as the better known black prince.

He said it has a call like a quacking duck and a yodelling sequence.