Spotlight on... Green-fanged Tube Web Spider

The Green-fanged Tube Web Spider 

A while back, botanist Brian Laney contacted TVERC asking us whether we had any records of this spider, the Green-fanged Tube Web Spider (Segestria florentina)  as he wanted to see one. When I did a bit of research, I definitely could understand why.

It’s the UK’s biggest segestrid spider. The female is black and can have a body as long as 22mm. As their name suggests, they spin a cylindrical web, usually in a crevice in a wall or tree, or perhaps in a gap between stones or planks. The exit to the tube is covered by a circular section of web with extending “trip wires” and looks a bit like a bicycle wheel. The spider sits near the entrance of the tube with its forward pointing legs (an adaptation to tube living) in contact with the “spokes” and will dash out and bite any unfortunate creature (or nosey naturalist) by injecting it with venom through its fangs. Its most common prey are apparently moths, cockroaches, bees and wasps. The female has metallic green fangs (hence its common name). She lays eggs from September onwards in her tube, normally located in a south facing crevice.  These hatch in the spring and the spiderlings will often devour her as their first act, something known as matriphagy and not uncommon with spiders.

Where are Green-fanged Tube Web Spiders 

This species used to be confined to the UK’s south coast, but like many species, it has recently moved in land and is now found throughout the south-east. It’s difficult to say how common it is because it’s very under-recorded. TVERC only had 2 records, one from the south of Oxfordshire and a rather vague one from Cowley in Oxford (only a 1km grid reference, not very useful when hunting a spider!). Despite what might seem like the spider equivalent of a needle in a haystack, we can report that Brian has now found a green-fanged tube web spider in central Oxford in a south-facing hole in one of the college walls. So, keep a look out on your travels and see if we can add any more records of this species to the three we now have.

Have you seen any Green-fanged Tube Web Spiders?

If you spot any wildlife when you’re out and about, share your records and photos with TVERC. By letting TVERC know what you have seen you will help protect and improve your local environment by increasing the quality and quantity of data we hold. Photographs are always helpful too, as we keep an image gallery of species found in Oxfordshire and Berkshire.

Absence records are also very useful, so also let us know if you’ve been out and haven’t seen anything!

Your records can inform a variety of exciting biodiversity projects and help people make informed decisions about how to develop and manage land sustainably. We are a ‘not for profit’ organisation so rely on valuable help from skilled volunteers to improve our database.