Kwinana Rockingham Mandurah Branch, 20 July 2026
The July General Meeting was a Members’ Night. The first presenter was Daniel Heald, who gave a short presentation on Glow Worms of New Zealand. Daniel provided the following summary of his talk.
There are a wide variety of bioluminescent microorganisms and animals in the sea, but only a handful that live on land. It may have originally evolved as a way for cells to mop up free radicals, but these days bioluminescent invertebrates use it to signal for mates (e.g. Fireflies and related beetles), advertise their poisonous nature to nocturnal predators (e.g. California’s glowing millipedes) for reasons that remain mysterious (at least 40 species of earthworm, including NZ’s largest Anisochaeta gigantea – 150cm long), or lure flying insects to their doom – most famously, the Glow Worms of New Zealand.
Arachnocampa luminosa – ‘luminous spider-worm’ – is a Keroplatid fungus gnat whose worm-like larvae have brightly blue-glowing Malpighian tubules. These are the insect equivalent of kidneys, and since they don’t change much with each moult, both the pupa and the short-lived adults are faintly luminous.
But the larvae live on damp overhangs, underneath fallen trees, on riverbanks, and in caves, and spin slimy silk traps to catch any insects that mistake them for stars. They will also eat any neighbouring larvae that try to move into their patch of cave roof. Large colonies will synchronise the brightness of their glow to attract prey better.
One of the first people to rear the Glow Worms to adulthood was George V. Hudson (1867 – 1946), an amateur entomologist most famous for proposing daylight saving time – so he’d have more time for insect collecting after work.
New Zealand has a single species of Arachnocampa, but Australia has eight, all in the Eastern States, mostly near the coast. One is known from a single cave in Victoria, but others have occupied disused train tunnels in the Blue Mountains and find them quite to their liking.
Other Keroplatids are also known to glow – the ‘Dismalites’ (Orfelia fultoni) of North America emerges from crevices in the ground to spin traps strong enough to catch cockroaches, but also feeds on fungal spores. And Keroplatus nipponicus of Japan spins webs underneath shelf fungi, but appears to be entirely fungivorous, making their glow something of a mystery,
The next presenter was Chris Punter, who shared some images taken during the KRMB excursion to Dryandra NP in spring, 2025.
Colin Prickett