This Week, Be Kind to the Itsy Bitsy Spider

This week is Be Kind to Spiders Week! With over 50,000 species of spiders balancing our ecosystems across every continent except Antarctica, they are crucial to maintaining global biodiversity. To celebrate, Nilo Mason discusses the anatomy and importance of spiders, and delves into spider conservation - both large and small scale. Read on to work towards overcoming your eight-legged fears and start appreciating spiders instead!

What Makes a Spider?

Spiders are in the same animal class as scorpions, mites, and ticks- the Arachnida. Arachnids are defined by having eight legs, a hard exoskeleton, and a body segmented into two main parts: the cephalothorax (a fused head and thorax) and the abdomen. Although having eight legs might look creepy to some, I invite you to discover spider paws! Known as tarsi, spider feet are fluffy and can resemble dog or cat paws.

An up-close image of a pinktoe tarantula (Avicularia avicularia) tarsi. Image Credit: Jenn on Flickr.

Matching their number of legs, most spiders also have eight eyes, with only a few species sporting six or fewer. Despite this, spider vision is lacklustre because each eye consists of a single lens instead of a compound structure like other insects. However, jumping spiders are on the other end of the spectrum, with their sight rivalling human vision: these species are capable of seeing in both UVA and UVB, as well as sometimes in extraordinary colour.

Another well-known feature of the spider is their ability to spin webs. Web-spinning spiders keep liquid silk inside internal silk glands before transporting it to their spinnerets, where it gradually hardens enough to form fibres. They manipulate this thread with their hind-most legs to create webs, egg sacs, and even bridges.

A garden spider (Araneus diadematus) in its web. Image Credit: Enri on Flickr.

Why Celebrate Spiders?

So why do spiders matter? Not only do they play an essential role in our woodland ecosystems, but they also protect our crops, benefit us in our homes, and contribute to scientific advances.

In the wild, it is estimated that one spider can eat up to 2000 insects a year! They regulate the density of multiple lower trophic levels, keeping our ecosystems balanced and ensuring they don’t get overrun by insects. Furthermore, spiders eat pests that prey on crops such as aphids, grasshoppers, leafhoppers, beetles, and caterpillars. Reducing these pests directly decreases crop damage, which can increase yield for farmers and improve efficiency.

Spinning webs in our homes' corners, they catch and eat insect pests such as house flies, cockroaches, fleas, moths, ants, and even mosquitoes. Consequently, a spider roommate might reduce your chance of being bitten and contracting a disease.

Finally, spiders are incredible animals that have helped to advance science through their amazing silk and unique bodies. From research into spider brains (which have larger and easier-to-study neurons than we do), scientists were guided into discovering a new “waste canal system” in which the human brain internalises waste from healthy brain cells. This canal system can become swollen and has a role to play in humans with Alzheimer’s disease, so the more research we can do now, the better preventative measures we can employ.

Another example of spiders in biomedicine is the use of spider silk in regrowing nerve fibres, indicating that a spider silk nerve conduit could be just as efficient as current nerve implants. Hopefully, spider silk will provide a new way to treat people with long-term nerve defects!

Lastly, spider silk is being used to create bulletproof armour. Researchers at Utah State University have genetically modified silkworms to produce spider proteins in their silk, combining the high silk production of silkworms with the double strength and higher elasticity of spider silk. Current vests require 33 layers of aramid (a kind of synthetic fibre) to stop a slow-moving .22 bullet, whereas only four layers of this new silk were needed to do the same.

Demonstrator of bullet-proof silk vest, an early example from 1923 of regular silk being tested. Image Credit: National Photo Company Collection on Wikimedia Commons.

Conserve our UK Spiders by Being Kind…

Unfortunately, of the 654 different species of spider dwelling in the UK, 16% are considered threatened. Like other terrestrial invertebrates, spiders face challenges such as being affected by pollution (pesticides), habitat fragmentation, and urbanisation.

Although some farmers opt for insecticides over general pesticides, it was found that these chemicals can alter the behaviour of bronze jumping spiders - although the spider is not killed, this type of pesticide still affects their ability to capture prey, thus causing an unnatural change to the ecosystem. Moreover, insects such as moths can develop resistance to pesticides. Instead, farmers should be encouraged to value and promote spiders as biological controllers to let them protect the crops naturally.

Habitat fragmentation caused by deforestation and urbanisation gravely threatens spiders that thrive in woodland habitats, like the UK buzzing spider. Without proper connections between habitats, species become localised and the gene pool reduces, leading to reduced prey options, inbreeding, and an increased risk of being wiped out by a natural disaster. Luckily, organisations (including the RSPB, Suffolk and Sussex Wildlife Trusts, Natural England, the Broads Authority, and the British Arachnological Society) can step in to save spiders affected by habitat loss and fragmentation. One example of a successful conservation effort by these groups is the reintroduction of Fen Faft spiders, a semi-aquatic species which hunt prey on the water’s surface, to the Norfolk and Suffolk broads. This action helped to recover a species on the brink of extinction, bringing their numbers up into the thousands. In the long term, legislation should be put in place to protect target land areas housing threatened spiders.

Deforestation by burning to make way for agriculture, displaying an example of habitat loss and fragmentation. Credit: Jami on Wikimedia Commons.

A Fen Raft spider on the water. Credit: Holger on Wikimedia Commons.

But how can we help? A really good start is not squishing them! If you find an unwanted spider in your home, choose kindness and gently relocate it outside. To go the extra mile, consider participating in the spider recording scheme, where you record and send data to the British Arachnological Society to help them focus conservation efforts where needed. There are also steps you can take to encourage spiders to your garden, try including log piles, more leaf litter, a cluster of rocks, or a loose layer of mulch.

Hopefully, learning about the wondrous world of spiders has increased your respect for, and interest in, these amazing creatures. If you are still scared of spiders, remember that they are more scared of you than you are of them! If you live near London, consider signing up for the Friendly Spider Programme, a course run at the Zoological Society of London that is designed to help people overcome arachnophobia. Happy Be Kind to Spiders Week!

Macro-shot of a cute zebra jumping spider (Salticus scenicus). Credit: Erik on Pexels.

About the Author:

Nilo Mason is a passionate Zoology student on placement as a Research Assistant at Dartmoor Zoological Society with a deep commitment to wildlife conservation and educating the public about biodiversity. Through his work, they strive to bridge the gap between people and nature, promoting the preservation of our planet's incredible wildlife. You can follow them on LinkedIn: www.linkedin.com/in/nilo-mason