The spider invasion explained

By Martin Askins
Wiltshire spider expert

You may have seen numerous Araneus diadematus in your garden this Autumn

Summer draws to a close, the days shorten, autumn creeps in... and so do the creatures of the night.

This is particularly concerning for the arachnophobes amongst us.

Because this is the time of the year when you are most likely to be disturbed of an evening by a number of large, hairy, eight-legged visitors to your home.

And according to some reports, this year might be worse than others, as spiders appear to be more numerous than usual.

The reason? According to Matt Shardlow, chief executive of BugLife, the temperate summer which we've had this year should've been kinder to our spiders.

Our spiders are adapted to our climate - so hot summers tend to desiccate them and wet ones put a dampener on their activities.

This is also true of insects - one of the spider's main items of prey (all spiders are predators).

However, though there is anecdotal evidence of a recent boost in numbers, I'm not yet convinced that it's any greater than in other years.

BugLife have initiated a 'Spider hunt' which may produce some quantitative data.

BugLife: Spider hunt

There are, in fact, 650 or so different spider species known to occur in the UK, about 350 of which have been found in Wiltshire.

Some are mature all year around, some in the spring to early summer and some in the late summer into autumn.

The peak in autumn is probably more noticeable to the general public as the species involved are larger and associate more with man than the spring-maturing ones.

Some spiders to look out for:

There are several Tegenaria species in the Wiltshire area

Tegenaria species

The spiders which possibly account for much arachnophobia are the long-legged Tegenaria.

These are the ones that do the scuttling at this time of the year, probably late at night when you're watching Alien on the TV.

During the rest of the year they sit on their sheet-webs, tucked away in quiet corners in and around your home, snacking on the occasional insect that trundles on to their web.

Come autumn and they mature so the males go in search of love, usually after sundown as they're less obvious to the animals that prey on them.

There are several Tegenaria species in the region.

They are not completely black but actually subtly patterned in black on a brown background - though most people probably won't examine them close enough to appreciate this!

Araneus diadematus

This is another web-spinner, known as the garden spider or 'cross-spider' due to the pattern of white spots on its abdomen.

At this time of year the females become gravid with eggs and their rotund forms can be found, head down, sitting in the middle of their orb-webs.

These are built on structures such as bushes which are stiff and open enough to support them. They are widespread, not only occurring in gardens.

Araneus quadratus

Easily recognised by the four white spots on the abdomen, this is another orb-web weaver, less likely to be found in the garden than Araneus diadematus but quite common on the chalk grasslands.

Well-fed females are amongst the heaviest of all British spiders.

Their webs are quite strong and sticky and can be noticeable if you stumble through them in the field.

Metellina segmentata is a smaller orb-weaver

Metellina segmentata

Metellina segmentata is a smaller orb-weaver than Araneus diadematus and hence less noticed but probably more widespread and numerous.

Its web is more loosely woven with fewer radial spokes and a wider spiral than that of Araneus diadematus.

Linyphia triangularis

Linyphia triangularis builds a sheet web slung in interstices in bushes and shrubs.

Unlike Tegenaria species, Linyphia sits underneath her web, waiting for prey to fall on its upper surface.

Another widespread species, you'll probably find her in your garden

Scotophaeus blackwalli

This spider is probably adult throughout the year.

Unlike the other spiders described here, it doesn't build a web to trap its prey but actively hunts them.

It comes out at night and can be found patrolling the walls of buildings, sometimes wandering indoors.

It has relatively short, stout legs in comparison with the Tegenarias.

It is un-patterned but has a glossy grey coat, prompting some to call her the 'mouse spider'.

Steatoda grossa builds its web in undisturbed corners of buildings

Steatoda grossa

This spider is probably adult throughout the year.

Nationally it appears uncommon, but I suspect it's present in many houses in Wiltshire.

It builds its tangled web in undisturbed corners of buildings, especially garages, lofts, conservatories.

It has a glossy, dark purple abdomen which has a lighter chevron pattern in immature animals and males, though the females can be darker overall.

It will quite happily feed on woodlice and their husks, sucked dry by the spider, can often be found below the webs.

Visit Martin's site, The Spiders of Wiltshire, for further information about the many types of spiders that inhabit the county.

The Spiders of Wiltshire