Tag: entomology

Spiders: Super, Not Scary!

Related to insects, arachnids are a fascinating group of invertebrates. Several species of spider can be found in and around our home at this time of year, but not everyone welcomes them! Here we take a look at some of these super spiders and why there is no need to be scared.

Most spiders don’t want to come into our homes because they are too warm, too dry and there isn’t enough food (or perhaps they feel the same way about humans as many people do about spiders!). A few species do venture into our dwellings and have probably been associated with us for thousands of years and often perform a useful housekeeping job in reducing the number of flies inside the home.

House Spider (Tegenaria domestica).

The House Spider builds a funnel-like web. It sits inside waiting for prey to land on the web, emerging quickly to trap it. Indoors, this is the spider we are likely to find in the bath! Some people feel alarmed by them, but they are completely harmless and will retreat into the plughole (or their funnel web) if they feel threatened. The males are active in the summer so when you see a house spider indoors it will probably be a male looking for a mate. The females usually eat them after mating, so the House Spiders you may find in your home in the late autumn will probably be females which can live for two years or more.

Giant House Spider (Eratigena atrica).

The Giant House Spider has a similar appearance to the house spider but is larger. Females can grow up to 18mm in body length with a leg span of 45mm. Those long legs enable them to be one of the fastest running spiders: they can move at up to 0.5 m/s (1.2 mph). Their speed of movement can be startling but they are in fact easily outpaced by normal human walking speed (4 mph). They only use their speed for short bursts and the females normally stay within their funnel webs. It’s the males we see out and about in our homes in summer and autumn, looking for mates. Although the mouth parts of these spiders are theoretically capable of piercing human skin, they prefer solitude and to retreat when startled and so only bite rarely when provoked. Their venom cannot harm us.

‘Money Spider’ (Linyphia sp.)

‘Money Spiders’ are not a single species. Hundreds of different small spiders are called ‘Money Spiders’. In the UK they usually belong to the Family Linyphidae. They get their common name from a folk saying that if one lands on you it’s lucky because it will spin you some clothes, meaning you will come into some money. If anyone has ever had a garment spun by a spider we’d love to hear about it! Money Spiders often land on us in the summer because they travel through the air on strands of silk, a method called ‘ballooning’. Money Spiders are completely harmless to humans and most go entirely unnoticed by us because they are so small.

Daddy Long Legs Spider (Pholcus phalagiodes)

The Daddy Long Legs Spider is also known as the ‘Cellar Spider’. It prefers to spin loose strands of web in corners which it uses to capture prey. It is not to be confused with the Crane Fly, also called a ‘Daddly Long Legs’ in the UK, which is a fly, so has a pair of wings. These spiders will often start vibrating if you come close in an effort to scare you off. Alternatively, they may curl up completely and ‘play dead’. They are completely harmless.

Garden Cross Spider (Araneus diadematus).

The Garden Cross Spider is usually found in the garden, but sometimes venture into our homes, as shown in the picture. They are large web-spinning spiders. Their webs are usually very noticeable on autumn mornings, revealed by drops of dew sticking to the strands. They can be recognised by the distinctive cross pattern on their back. The body of females can be up to 15mm long, although the males are a lot smaller and so we rarely notice them. Females can often be found protecting a ball of eggs or young spiderlings. They will be defensive of these, but are completely harmless.