The Australian house spider (Badumna is far away) originates from Australia. This eight-legged creature often lives close to humans: high up in bushes or behind the bark of trees in urban areas and in and against buildings or other human constructions. It is easily dragged and has long established itself in North America and New Zealand and it also has populations in Argentina, Mexico, Brazil, Uruguay, Japan and South Africa. Observations have been made in Europe since 2010: initially these were imported specimens in Germany and England. In the meantime, extensive settlements have been reported in England, often associated with garden centres and gardens.
Dutch observations
In the Netherlands there are now also photos of this species on the website Waarneming.nl. In October 2021, the first specimen was captured on photo in Zevenhoven. Then in June 2022 a photo of the spider in Almere followed.
In November 2022, Martijn Wiersma found a specimen on an industrial estate in Uithoorn, on the outside of a building that houses a furniture wholesaler. There are many companies in the immediate vicinity that import goods, especially plants. It soon became apparent that there was a good population there, because the species could be found on the facade of the company almost every week, sometimes with as many as ten specimens at a time. To this day, the spiders or their webs are regularly found there. In the summer of 2024, Martijn also found an Australian house spider in its web on the outside of a plant trading company in Ede. A web of the Australian house spider was also found in a garden centre in Almere this summer.
Literature also shows that mainly plants and trees provide the supply of spiders. In the spring of this year, however, the Knowledge and Advice Centre for Animal Pests received Australian house spiders that had been collected in a container from Australia with animal feed ingredients on pallets. So there are also other supply routes than plants.
Recognition
The Australian house spider is easily recognizable by the characteristic pattern on the upper side of its body. They usually live hidden in a hole at the back of their web. This web is very different from spiders that make ‘orb webs’, and is a messy whole of criss-crossing threads on a flat surface and facing forward. In order to see the spider, it has to come out of its hole and enter its web. This requires some patience – or an insect thrown into the web – from the observer.
Expansion?
It is possible that the Australian house spider will establish itself extensively in our country. If the spread occurs via plants, as has been shown for some countries, then it can go quickly, because in the Netherlands the trade in this is extensive. The species may become a competitor for other spiders around buildings, such as night-cracker spiders.
If there is an advance, we hope to be able to document it. The request is therefore to look for this species in your own garden and possibly in garden centres or other places where plants are sold. Photos can be entered on Waarneming.nl.
Text: Jinze Noordijk, EIS Insect Knowledge Center
Photos: Martijn Wiersma
