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Being a wasp parent may be the key to your ‘spidey’ troubles.
Imagine being in a hurry to get to work only to realise that a large, hairy, eight-legged creature has been camping inside your shoes!
Depending on your perspective, spiders are either one of Australia’s great delights or a total menace. Their resilience makes them particularly suited to survive in the wild, in your cupboard or even sapped between blocks of ice in subzero temperatures.
Fortunately, an unexpected soldier might be willing to save the day.
Enter: the spider wasp, with shimmery, bronze wings and a metallic-blue tint.
It comes equipped with two golden antennae on its head which help it find spiders to feast on for lunch. As the old proverb goes, ‘the enemy of my enemy is my friend’.
The orange spider wasp (Cryptocheilus bicolor) is the most commonly seen Pompilid wasp in Australia and is a voracious predators of huntsman spiders. Image: Jean and Fred Hort/Flickr, CC BY 2.0.
'The spider wasp rarely stings humans unless provoked,' says Dr Chris Freelance, an ecologist and science communicator at Austral Ecology, who presented at this year’s Pint of Science Australia festival in Bendigo.
'The sting of the spider wasp is the second most painful of any insect,' he says. We know this because of the daredevil entomologist Justin Schmidt who took upon himself to document various stings in the Schmidt pain index in the 1980s. According to Dr Freelance, he described this pain as 'blinding, fierce and shockingly electric'.
Working stealthily, spider wasps hunt for arachnids using a combination of their acute sense of smell and vision, along with the ability to pick up on faint, acoustic signals.
Spiders mainly use their feet to send vibrations through the ground which can be picked by other spiders using special sensory features called sensilla located on the bottom of the feet.
The wasp can eavesdrop on these signals using extremely sensitive receptors before scurrying off to hunt for its prey. The complexity of these receptors varies according to the type of spider a particular sub-species of the wasp hunts. The ones that prey on nocturnal spiders usually rely on acoustical hints and, as a result, have smaller eyes and more audio receptors on their antenna.
Often, the odour of the spiders is a giveaway which the wasps utilise fully. Using tiny hairs present in the sensilla – which are no bigger than few thousandths of a millimetre – the wasps locate spiders by sniffing out their pheromones.
Spider wasps can easily carry and drag paralysed spiders many times their own bodyweight. Image: Bill & Mark Bell/Flickr, CC BY-NC-SA 2.0.
Interestingly, it is the female spider wasp that does all the hunting and is responsible for bringing food home. Not only will the female fatally paralyze a spider (which might be twice its size) but will drag, lift and do everything in its power to get the dead spider across to a burrow, which it has dug beforehand, only to lay eggs on it.
However, a rapidly changing world is causing problems to our silent soldier. 'The biggest of all being loss of habitat, followed by chemical and light pollution which masks subtle odours and vibrations and make it difficult for the wasps to hunt for food,' says Dr Freelance.
These wasps can hunt spiders in or near cityscapes, but will need a soft, permeable surface to dig their burrows, where they can keep their loot. With an increasing number of concrete structures popping up, they are finding it difficult to break new ground – quite literally.
That is where each one of us can help by planting native plants which act as fodder for the wasps. This can ensure that they find plants to pollinate and survive.
If being a ‘wasp momma’ is not reason enough for you, Dr Freelance adds that venom in the sting contains certain compounds which, according to some studies, might help fight conditions like Parkinson's disease and Alzheimer’s disease one day.
So, there you have it, an almost perfect wasp buddy who is part detective and part soldier, willing to do an important job for you.
'Looking, but no touching is the mantra, if you ever happen to be near one,' adds Dr Freelance.
Dr Chris Freelance (Ecologist and Science Communicator at Austral Ecology, and Pint AU 2025 Festival Speaker)