We had our first firefly of the season in the house last night. They are rare visitors at any time of year and we don’t get any at all through the Dry season; we are just on the brink of the Wet now so it was unexpected as well as magical. They are always magical even for local people, I think, but I grew up in Victoria where they are completely unknown so they are even more magical for me than for people who have grown up in the tropics.

But this is (mainly) a natural history blog so let’s look at the science. They are beetles – technically a family, Lampyridae, in the order Coleoptera. There are about 2000 species worldwide, in temperate and tropical climates, and Australia has 25 species in four genera. Most of them are small (about 6 – 10mm) and dark coloured. Wikipedia says:

Many are in marshes or in wet, wooded areas where their larvae have abundant sources of food.

Fireflies hibernate over winter during the larval stage, some species for several years. Some do this by burrowing underground, while others find places on or under the bark of trees. They emerge in the spring. After several weeks of feeding, they pupate for 1.0 to 2.5 weeks and emerge as adults. The larvae of most species are specialized predators and feed on other larvae, terrestrial snails, and slugs.

… all of which accounts for why we rarely see them around the garden and never see them in the Dry.

I managed to catch one on my kitchen floor at exactly this time of year in 2011 for long enough to take photos:

Orange and black beetle on vinyl flooring
Firefly, about 8mm long, on vinyl flooring

It flew into a room with no lights on, so it was in a dark enough spot for me to notice it by its flashing. Graeme Cocks (Insects of Townsville) has identified three species around Townsville, all in the same genus, and mine seems to be Luciola nigra.

Firefly wings spread
Firefly taking off – mid-flash, given how bright the tail looks.

The timing of this shot was entirely a matter of luck. They are so small that you don’t notice them except in very dim light and they never settle for very long so getting any shot at all is quite difficult. In this case, I had it lined up and was simply taking as many shots as I could before I lost it again.

Wikipedia tells us that, “All fireflies glow as larvae. Bioluminescence serves a different function in lampyrid larvae than it does in adults. It appears to be a warning signal to predators, since many firefly larvae contain chemicals that are distasteful or toxic.
Light in adult beetles was originally thought to be used for similar warning purposes, but now its primary purpose is thought to be used in mate selection.”
Atlas of Living Australia adds: “Males fly just after dusk and emit a series of controlled flashes from the light organs as part of the mating sequence; females also flash but have not been observed to fly with the males. Synchronised flashing, well known in some New Guinea species, has been observed in North Qld. Adults are not known to feed, but larvae prey on small land snails.”

They are pretty to see along the river bank in the early evening – often ten or more slowly blinking as they move around. The nearest location I know I’m likely to see them is along the bank of Ross River. It must be time for an evening walk or ride along the bike path between Bowen Road and the Nathan Street bridge, looking down into the scrub.

More information

(The second reference is far more technical than the first.)

  • Australian museum: Blue Mountains Firefly (but note that it really only talks about one species – don’t be misled by the fact that it mentions “25 species”)
  • Lampyridae of Australia (Coleoptera: Lampyridae: Luciolinae: Luciolini). Authors: Ballantyne, L. A.; Lambkin, C. in Journal: Memoirs of the Queensland Museum 2000 Vol. 46 No. 1 pp. 15-93

15 thoughts on “Fireflies”

  1. They seem to start in the first week of September on one particular night – but I can’t work out if it is lunar, daylight (lengthening), darkness (shortening) or temperature related.
    In early September, if you walk on the Mundingburra section of the path along Ross River, between Aplin’s Weir and about Water St, they will be most prominent moving between the mangroves and the grass for just one or two nights before they are seen elsewhere.

    1. If they were glowing, they may well have been fireflies at whatever stage of their life cycle. The larvae look a bit like slaters – segmented – and I suppose they must start off very small. I have never seen one and photos are so rare I think hardly anyone else has seen one either, but I found a couple of photos from around the world. I will try to post them soon.

  2. I live at currumbin qld on the goldcoast and tonight we saw our first firefly it was slowly hovering over our roof out the front while I was taking the trash out at 6.30pm.
    So amazing never seen anything like it.
    And it’s 8th of August.

  3. In Paradise Palms area of Cairns, we saw a firefly on the 25th of January 2016 about 9pm.
    It was lovely to watch. (Coincidently there was a lot of rain the following night!?) I am not sure what conditions spark their appearance in an area. We have a lot of bush directly out the back.

  4. I have 2 in my bedroom right now & for the past week, blinking like a starry night in Kuranda! Pretty sure it was early Demcember last year when I woke up & there was one on my finger!

  5. I am at Atkinson dam out of Brisbane. The one fire fly at my window flashes repeatedly in response to my mobile phone screen being turned quickly in its direction. The timing of the flash is surprisingly very regular – at first I thought it was an electric device LED

    1. I remember hundreds of them on the point at the end of Campwin Beach [near Sarina, just South of Mackay] when I was a kid – so magical. Just low ?heath up there. No-one I’ve talked to now remembers them or says they’ve seen them recently.

  6. I saw my first one a week ago. Now there’s one on my roof flying around walking mostly. Blinking on and off green to yellow. It’s raining out side. This is so cool – we don’t get them down south. Up here I have seen two.
    We’re in Cairns region, there’s a creek just behind the house that’s where there coming from. My little girl just woke up she had never seen one either. How awesome fireflies are!!!

  7. Im in goldsborough valley south of cairns and it’s May. I was just down in a creek and watched a whole tree twinkling with them. Would have been at least 40. Also found larvae everywhere on the ground. Was amazing.

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