False Black Widow spider - Steatoda grossa - found in the Canary Islands
Also known as the Cupboard Spider
The spider known to science as Steatoda grossa is otherwise known as the False Black Widow and the Cupboard Spider. I have two here living predictably in a cupboard in my apartment here in Tenerife in the Canary Islands.
The female has been living there for some years now and I tend to regard her as part of my household but I have been wondering how she will ever find a partner, not having seen any more of her type around. Recently a much spindlier and smaller spider has arrived and is clearly a male. How did he find the lady of his kind? Where did he arrive from? How long has he been travelling?
A lot of people hate spiders and there is the fear of them known as arachnophobia but I am a person who is fascinated by these little animals and tend to leave them be. I currently have a large Garden Spider female here too and she has been living out on my balcony for the past couple of months in a most precarious position. I have no idea how she created her web that has had a line going over 6 ft over to a wall. Like I said, fascinating creatures!
Female False Black Widow
Like the Black Widow
The Cupboard Spider resembles the real Black Widow (Latrodectus spp) in shape and size but I knew the female I had here was not one because Black Widows have a red mark on their abdomens. The spider in my cupboard has yellow ones.
Incidentally a real Black Widow does live in Tenerife but I have not heard of one report of this spider in the six years I have been on the island so it is presumably very rarely seen and very rarely causes any problems anyway.
Nevertheless my copy of David and Zoe L. Bramwell's excellent La Historia Natural de las Islas Canarias ("The Natural History of the Canary Islands") has the Black Widow ("Viuda Negra") species L. mactans listed and it says it lives in dry and sandy areas amongst short vegetation. My book also says it is found on Lanzarote, Gran Canaria, La Gomera and El Hierro.
Concerning the False Black Widow the same book states that it is a cosmopolitan species and usually encountered in houses and buildings where it feeds on insects and other spiders. It lives on the same islands as the true Black Widow, and Wikipedia says it comes from Australasia, North America and Europe. It clearly gets around and causes hardly any problems at all.
Apparently the females of the False Black Widow can live up to six years but the males only get one to one and a half and die shortly after mating. In the real Black Widows the females kill and eat the males at this time and that is how they got named.
I think this female still has a couple more years to go so she can stay safe in my cupboard here. If she mates with the male that has found her I suppose we can be expecting a lot of babies at some point later. Not sure what I`ll do about that and I will deal with that when and if it happens. I usually find that spider nests disperse themselves after the mother abandons looking after her little ones and most are never seen again. They go off into the world to survive or perish along the way, beset as they are by all sorts of predators, and having to beware of many a human too!
False Black Widows make a scruffy and tangled web and the female in my cupboard often gets hers broken a bit by me, although I try to be careful when moving stuff around and leave her space alone. Of course repairing her web is something for her to do in her long and lonely hours in the dark spent hanging around, literally! I wonder what goes on in a spider's mind. How do they measure time? They seem very content creatures that set up home and make do with whatever life brings!
A mating pair of Steatoda grossa
Wikipedia describing the False Black Widow says: "They are not aggressive, and most injuries to humans are due to defensive bites delivered when a spider gets unintentionally squeezed or pinched."
However, it notes that the bite of this species can cause blistering and a feeling of "malaise" for a few days afterwards. There are no long-term effects though and it very rarely bites anyone.
Female spider with babies
Well, many months have gone by since I first published this and now I am very pleased to say that in the cupboard here the female spider's eggs have all hatched out today and she is surrounded by her babies.
So I have been able to watch the whole incredible life cycle take place in my cupboard. The female I left living there and eventually a male of her species arrived. The pair must have mated because he disappeared and she went on to spin an egg cocoon.
Now several months later the little spiders have hatched. I am leaving them to wander away. Each one now has to take its chances in the world and will find its own home where it can spin a web in some dark corner.
Copyright © 2012 Steve Andrews. All Rights Reserved.
Link for Steatoda grossa
- The truth about false widow spiders - Natural History Museum
What's the likelihood of being bitten by a false widow spider? Extremely low. No one has ever died of a spider bite in the UK and the number of reported bites from spiders in general is minimal. The Natural History Museum's Insect Information Service
- Steatoda grossa - Wikipedia, the free encyclopedia