Spiders: our eight legged allies

Sun jumping spider (Heliophanus cupreus) © Josh Phangurha 

Some of the most fascinating inhabitants of gardens are greatly overlooked and rather unpopular. In today's blog Josh Phangurha, one of our Trainee Ecologists, talks about creating a spider-friendly garden and some fascinating finds from his own.

Lockdown has been difficult for all of us, but for many people it has put a focus on the wildlife that call our gardens home. Popular species that visit gardens include various birds and mammals, and although I greatly welcome both, some of the most fascinating inhabitants of gardens are greatly overlooked and are rather unpopular. I’m talking about the spiders!  

According to the World Spider Catalogue, there are approximately 48, 559 spider species worldwide with around 670 species living in the UK at the time of writing this blog. Hampshire is blessed with good spider diversity due to the county’s array of special habitats. Some of these species are localised or nationally scarce and can sometimes turn up in gardens. The aim of this blog is to raise awareness about the importance of these seldom-mentioned animals, the myths that come with their reputation and how you can explore the weird and wonderful world of spiders in your garden. 

Why care about spiders? 

Well, a relatively recent study managed to statistically estimate that spiders worldwide eat 400-800 metric tonnes in insect flesh every year. For context, humans consume around 400 metric tonnes in meat and fish every year1. A staggering statistic! Without spiders we would be absolutely overrun with insects, including disease-spreading and crop-destroying species.

Furthermore, research is beginning to reveal how the presence of spiders in ecosystems influences the behaviour of insects in a way that prevents particular plant species being over-eaten. This results in greater plant diversity, which promotes improved biodiversity across all species2

Flower crab spider (Misumena vatia) male

Flower crab spider (Misumena vatia) male © Josh Phangurha 

How do you find spiders in your back garden? 

Explore at night - Many British spiders are active during the hours of darkness and it is this time of day when some of the most fascinating behaviours are observed. For example, going out into my garden with a torch has revealed mating woodlouse spiders (Dysdera crocata) on the garden wall and spider-on-spider predation, including a large house spider (Eratigena sp.) eating a male Black Lace Web spider (Amaurobius ferox) and a Noble False Widow (Steatoda nobilis) wrapping up two woodlouse spiders at once! It’s a spider-eat-spider world out there. I also once observed a Sac Spider (Clubiona) tackling a fly that was bigger than itself.

Tickling webs - Mimicking the movement of prey on a spider’s web can sometimes reveal the occupant. This can be achieved by gently applying the vibrations of a tuning fork or an electric toothbrush to the silk, or simply wiggling a fine piece of grass. This is a great way to become familiar with the different types of web that different spider species build. For example, some species build webs that are structured in the form of a sheet, such as House Spiders (Eratigena sp.), whereas some build the more typical orb web, such as Garden Cross Spiders (Araneus diadematus). An example of a less familiar web structure is the tube web, which has ‘trip lines’ radiating around a hole in a wall/tree. These are built by spiders in the Segestria genus (Commonly known as ‘Tubeweb Spiders’).

A tube web spider at the entrance of the web. Silken -trip-lines’ radiate around the entrance.

A tube web spider at the entrance of the web. Silken -trip-lines’ radiate around the entrance. © Josh Phangurha 

Lifting stones and logs - This is a good method that often reveals various invertebrates. I have found Stone Spiders (in the genus Drassodes) in this way, as well as ground-dwelling crab spiders in the Xysticus genus, which are very charismatic!

A crab spider in the genus Xysticus

A crab spider in the genus Xysticus © Josh Phangurha

Creating a range of habitats - A greater diversity of wild plant species in the garden often results in a wider range of spider species. Although there are many spiders like artificial environments, there are also many others that prefer to live in open grasslands and woodland/scrub. Leaving a patch of rough grass/scrub in the garden will attract many spiders species, as well as the insects that they hunt. If you can implement Ox-Eye daisies into this it can be particularly good for one of our most spectacular species, the Flower Crab Spider (Misumena vatia). There are species that like to live higher above the ground too, which is where having shrubs, scrub and perhaps even a mature tree or two becomes important. Species that like this sort of habitat include the gorgeous orb-weaving spider Araneus triguttatus, the exquisite green crab spider (Diaea dorsata) and the uniquely patterned Laceweb Spider Nigma puella. If you’re really lucky, you may attract the seldom seen and remarkable Triangle Web Spider (Hyptiotes paradoxus).

You may be wondering how spiders colonise these habitats as they can’t fly like many other invertebrates…or can they? The spiderlings (that’s baby spiders) of many species have the ability to use a special type of silk as a parachute when the wind picks up. The tiny spider, having only recently hatched from the egg, will often climb to the top of a plant and raise its rear end upwards while releasing this silk. When the spiderling feels a strong enough gust of wind, it will let go of the surface it is standing on and will be carried through the air. They can sometimes travel thousands of miles across oceans in this way, but may also land just a few miles or just meters from where they took off. This behaviour is known as ballooning. Have you ever discovered a small spider crawling on your clothing and wondered how it got there? Ballooning is probably the answer! So, if you create the habitats, the spiders have no trouble in finding them.  

During the Covid-19 lockdown, I have captured as many spiders on camera as I can within the walls of my urban garden in Southampton, which has unravelled remarkable diversity in what would appear to be an unlikely place. I encourage you to do the same, as spiders are one of the true marvels of the natural world and there is so much that we don’t know about them. Here are my best finds during lockdown:  

References 

1.    https://www.theguardian.com/environment/2017/mar/14/spiders-insects-foo…
2.    http://www.indefenseofplants.com/blog/2017/5/4/how-spiders-increase-pla…?
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