Life Science Environment Australia’s fireflies among those in trouble amid global extinction threat
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Australia’s fireflies among those in trouble amid global extinction threat

Fireflies
Japan was lit up in 2016 by a swarm of fireflies. This stunning display is unlikely to be seen in Australia, however. Photo: Getty
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Australia’s firefly species might be relatively unknown but they’re still at risk of being decimated, as the global population feels the threat of extinction.

The world’s 2000 species of firefly are fighting the growing weight of habitat destruction, light pollution and the continued use of pesticides, which, combined and separately, could wipe out colonies and entire species.

Global experts in the insect (which are actually beetles, not flies) were surveyed by a team of researchers about how their particular country’s firefly populations were thriving (or barely surviving).

The results revealed the world’s population was at a high risk of extinction, mostly because of three key factors – and Australia’s 25 species aren’t immune.

Habitat loss was the main impactor on firefly population – and it’s been recently replicated here with the summer of bushfires, Australia’s leading firefly expert says.

Lesley Ballantyne has been studying the critters since 1961, and said the country recently lost a population to the New South Wales bushfires.

When fire ripped through Kangaroo Valley, it took out a substantial number of Blue Mountain fire flies, Dr Ballantyne told The New Daily.

Now that population is gone and the area will have to be “re-invaded” by the species, Dr Ballantyne said, but there’s no guarantees that will work.

This particular population was only discovered a couple of years ago, and was in a bushy corner on someone’s private property. That’s where you’ll find most fireflies dwelling in Australia, Dr Ballantyne said.

Not a lot of people are aware the country has fireflies, let alone two dozen different species, because they’re not in places commonly seen by the public.

“They only live in areas where there’s moist undergrowth,” Dr Ballantyne said. And most of those areas – dense scrubland, rainforests, mangroves and national parks – tend to be inaccessible by the everyday person.

Male firefly
Fireflies aren’t actually flies, they’re beetles. They only emit light for about three weeks of their two-year life cycle, and it’s the males that do so, as part of a mating ritual. Photo: Getty

Mostly, you’ll find them in Australia’s top end and down the east coastline, she said. Occasionally, you’ll be lucky to spot a couple in a suburban backyard in Brisbane’s outer pockets.

Because of their inaccessibility, it’s relatively hard to measure Australia’s firefly population.

In other countries, such as parts of Asia and the US, there are tourism promotions built around firefly season, Dr Ballantyne said. Ironically, some of these ventures are contributing to habitat loss, which is decimating populations.

Whereas in the US, scientists can use a range of factors to pinpoint exactly when the beetles will be firing, Australia’s unpredictable seasons mean that’s just not possible.

The life cycle of a firefly spans about two years, the majority of that spent as a caterpillar. There’s only about three weeks of a firefly’s life when they’re actually a ‘fire’ fly. It’s usually in summer, but just when that is will depend on the previous two years of rainfall, Dr Ballantyne said.

While our fireflies’ lives depend precariously on our climate and environment, we don’t have the added two factors that plague other countries’ populations, at least not to the same degree.

In East Asia and Southern America, artificial light at night  – illuminated billboards, street lights and the general glow from ever-expanding cities – is competing with and suppressing male fireflies’ natural instinct to glow and attract females.

An increased use of pesticides on agricultural land was the third identified global factor pushing down the population.

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