The 13 MOST Common SPIDERS Found in Ireland! (2023)
“What kinds of spiders can you find in Ireland?“
Many people are terrified of spiders and find them extremely creepy. This is unfortunate because not only are most spiders completely harmless, they are crucial to our environment by controlling the insect population. In fact, without spiders, our food supply would be in serious jeopardy.
Before we begin, I want you to know that the list below is just a fraction of the spider species found in Ireland. Because of the sheer number of these arachnids, it would be impossible to cover them all. For example, some estimates claim there are over 50,000 kinds of spiders on the planet (and the list is still growing)!
With that being said, I did my best to develop a list of spiders that are MOST often seen and easily identified.
Here are the 13 MOST common SPIDERS found in Ireland!
#1. Cross Orbweaver
- Araneus diadematus
Also known as the European Garden Spider, Cross Spider, Orangie, or Pumpkin Spider.
- Colors range from extremely light yellow to very dark grey.
- All individuals have white markings across the top of the abdomen, with four or more segments forming a cross (LOOK AT THE PICTURE ABOVE).
- Females range in length from 6.5 to 20 mm, while males range from 5.5 to 13 mm.
Cross Orbweavers are one of the most well-known spiders in Ireland.
These spiders are common in many habitats, including forest clearings, hedgerows, meadows, and gardens. They are also seen near humans, such as near buildings or lighted stairwells. Cross Orbweavers typically hang upside down at the center of their spiral webs.
Cross Orbweaver Range Map
Interestingly, when approached, they start shaking and vibrating their web in hopes of startling the perceived intruder. If this fails, then the spider will typically drop straight down out of sight. Luckily, Cross Orbweavers are not aggressive and typically only bite when accidentally grabbed. Bite symptoms include mild pain, redness, and swelling that lasts for a few days.
Believe it or not, these common spiders build a new web EVERY DAY. Yes, they eat the entire web every night and then begin construction on a new one. And lastly, if you are a male Cross Orbweaver, you must be careful with females, as you will often be eaten directly after mating!
#2. European Nursery Web Spider
- Pisaura mirabilis
- Slender abdomen with LONG legs (the fourth one is the longest).
- Colors range from light to reddish brown and from gray to black. A lighter stripe is visible down the middle of the back.
- The male is between 10 and 13 mm, while the female is 12 to 15 mm.
These spiders are commonly found in Ireland in tall grass, shrubs, or along the edges of woodlands.
Looking similar to wolf spiders, European Nursery Web Spiders get their name for how females protect their egg sacs. After carrying the egg sac in her mouth for a bit, she hides it under a leaf and spins a protective silk enclosure around the egg sac. From there, she sticks around to protect the babies until after their first molt. 🙂
European Nursery Web Spiders have a fascinating mating ritual! First, males find a gift, such as a dead insect, to offer to a prospective female. Then, after presenting the gift, the female will bite onto the gift if she is interested. From there, the male will move to deposit sperm with his pedipalps. WATCH THIS BEHAVIOR BELOW (and to see if the male survives)!
Interestingly, during copulation, the male almost ALWAYS keeps a leg on the gift, just in case the female decides to run away with it or attack him. If the female does change her mind about mating and starts to show aggression, the male typically will pretend to play dead until she calms down, at which point he may try mating again. The things spiders will do for love!
#3. Long-bodied Cellar Spider
- Pholcus phalangioides
- The cephalothorax (head) and abdomen are different shades of brown.
- Females have a body length of around 8 mm, with males slightly smaller.
- Legs are long and about 5 to 6 times the length of the body.
Do you know the spider that always seems to be in the corner of your basement? Well, it’s most likely the Long-bodied Cellar Spider! These long, thin, and delicate spiders are commonly found in Ireland in homes and buildings as they prefer warm habitats (they originate from subtropical climates in Asia). I know that every time I clean my basement with a vacuum, a few of these spiders end up getting sucked inside.
Long-bodied Cellar Spider Range Map
Some people find cellar spiders beneficial because they are known to hunt down and kill other types of spiders. But unfortunately, they will also eradicate native spider species. Interestingly, these spiders will leave their webs to hunt for other spiders! Once they find one, they subdue their victim, using their long legs to avoid being bitten in retaliation.
Despite their proximity to people, they are not dangerous and are not known to bite humans.
#4. Goldenrod Crab Spider
- Misumena vatia
Also called the Flower Spider or Crab Spider.
- Females can grow up to 10 mm (0.39 in) while males are quite small, reaching only up to 5 mm (0.20 in).
- They are usually yellow or white or a combination of these two colors. Shades of pale green and pink also exist.
- This species has a wide, flat body.
Crab spiders get their name from the unique way they can walk sideways, forwards, and backward, similar to a crab.
Goldenrod Crab Spiders primarily prey on insects much larger than themselves. To accomplish this feat, they rely on venom, which immobilizes their victims. But have no fear, as the venom is not dangerous to humans and their fangs are not powerful enough to penetrate our skin.
These spiders have the unique ability to change their color depending on the flower they are resting on, which helps them stay camouflaged as they hunt! Their color can also change depending on their diet, as colorful prey can show through their thin, transparent epidermis. For example, eating red-eyed fruit flies can make the abdomen turn pink. 🙂
#5. Zebra Jumping Spider
- Salticus scenicus
- Their anterior median eyes are large, which gives them excellent binocular vision.
- The coloration looks like a zebra; black with white stripes.
- Female spiders are 5–9 mm long, while males are 5–6 mm.
Zebra Jumping Spiders are primarily found in Ireland in open, vertical habitats. Rock faces and tree trunks provide good habitat, but they are also found in close proximity to humans on the walls of buildings and garden fences. You should also check the corner of the windowsills in your house, as they are sometimes found there too. 🙂
Jumping spiders don’t use webs to capture prey but instead use their incredible eyesight to hunt smaller spiders and other invertebrates. Once their victim is sighted, they move slowly towards it until they are close enough to jump on and make the kill, similar to how a cat hunts. Then, just in case they miss the target, they attach a silk thread to a surface so they can climb back up and try again!
Zebra Jumping Spider Range Map
To try and impress a potential mate, male Zebra Jumping Spiders will conduct a courtship dance by waving their front legs and pedipalps while also moving their abdomen up and down. A better dance increases the likelihood that the females will want to mate with the male. Males must be VERY careful when approaching the female; if the dance isn’t good enough, they risk being eaten.
#6. Walnut Orbweaver
- Nuctenea umbratica
- Wide and flattened with leathery skin. Females grow up to 15mm, males only 8 mm.
- Color ranges from red-brown and grey-brown to black.
- A dark, yellowish, leaf-like marking covers its back, where small dents are visible.
The best time to see this common garden spider in Ireland is at night.
During the day, Walnut Orbweavers, which are also called “Evening Spiders,” hide in all sorts of small crevices and cracks. Their flat body allows them to fit into some very confined spaces! They are often found in close proximity to people near garden sheds, fences, walls, or under bark.
Walnut Orbweaver Range Map
Once the sun goes down, these timid spiders build an orb-shaped web that can reach up to 70mm across. If you find one of these webs at night, you should be able to see the Walnut Orbweaver sitting in the center.
#7. Giant House Spider
- Eratigena atrica
- Mainly brown, but they have a lighter marking towards the front of their back with three light spots on each side that form an arrow-like shape pointing toward the head.
- Towards the back is a lighter middle line with six spots on each side.
- Their legs and body are hairy.
This species is one of the LARGEST spiders in Ireland!
The bodies of females can reach 18.5 mm in length, with males slightly smaller at around 12 to 15 mm long. Their long legs make them appear even larger, as the leg span of females can measure up to 45 mm!
Giant House Spider Range Map
Naturally, Giant House Spiders are found in caves or forests under rocks. But they have adapted well to humans and now are commonly found in peoples’ homes in corners or other rarely disturbed places. Like most spiders, they possess venom to subdue their prey, and if you are bitten, the effects of the toxins may be felt. Luckily, they rarely bite unless provoked.
You may be surprised at how FAST Giant House Spiders are! In fact, they held a Guinness Book World Record for the fastest spider species until 1987, when it was dethroned by solifugids, which I don’t think should count since they aren’t even true spiders!
#8. Cucumber Green Spider
- Araniella cucurbitina
- Females can grow up to 4.5–9.5 mm, while males only up to 3.5–4.5 mm.
- Adults have a distinctive yellowish-green abdomen with small black dots.
- The rest of the body is light yellow to red-brown.
Cucumber Green Spiders in Ireland blend in well with their surroundings.
Look for their orb-webs weaved between leaves and flowers along the edges of woodlands, hedgerows, and other wooded areas. These spiders should be a welcome addition to your garden, as their favorite foods include flies, aphids, mosquitoes, and midges!
Cucumber Green Spider Range Map
Another species, Araniella opisthographa, is almost identical to the Cucumber Green Spider. The only way to tell them apart is by using a microscope.
#9. Raft Spider
- Dolomedes fimbriatus
- Adults are dark brown with a white, cream, or yellow stripe along both sides of their bodies.
To find this spider in Ireland, you will need to find freshwater!
Raft Spider Range Map
Raft Spiders are incredibly unique and are considered semi-aquatic. Therefore, the best places to find them will be hunting on the water’s surface of freshwater wetlands. To find prey, they detect small vibrations by using their stretched-out front legs. Their typical victims include water beetles, pond striders, and dragonfly larvae, but large individuals have even been known to eat small frogs!
Interestingly, Raft Spiders can fully submerge themselves underwater! To avoid getting eaten by a bird, they often dive underwater for several minutes until the danger has passed. They also hunt underwater! WATCH BELOW.
Lastly, females are one of the few spider species known to attack nearly ALL males that try to mate with her. Evolutionarily speaking, biologists are perplexed by their extreme aggression because it can be hard for successful copulation to take place. 🙂
#10. Silver-sided Sector Spider
- Zygiella x-notata
Also called the Missing Sector Orb Weaver.
- Females have a body size of 5-11 mm in length, while adult males have a body size up to 7 mm.
- The head and legs are yellow-brown.
- The abdomen has a silvery sheen and a wavy leaf-like mark.
Silver-sided Sector Spiders are common in Ireland in areas inhabited by humans.
Their orb-webs are often found on walls, fences, window frames, and even on boats and docks. Naturally, these locations are incredibly sought after by these spiders, so don’t be surprised if you find multiple individuals living extremely close together, with each one residing in its own web.
It’s possible to identify one of these spiders just by looking at its web! You will notice a missing section at the top of the web, but if you look closely, you should see a “signal thread” that connects the center of the web to where the spider is hiding.
The signal thread is like a safety line. The spider attaches it to the surface it is jumping from so that if it misses its target, it can climb back up and try again. This spider often sits away from its web in a “retreat” but is still connected by the signal thread. That way, it will know immediately when anything makes contact with the web, such as its next meal.
#11. False Black Widow
- Steatoda grossa
Also known as the False Widow, Cupboard Spider, or Dark Comb-footed Spider.
- Females measure 6-10.5 mm in length. Males are similar in size but thinner.
- Dark colored with a round, bulbous abdomen.
- The female abdomen is more rounded than the male.
As the name suggests, many people commonly confuse this spider with the venomous Black Widow. But luckily, Steatoda grossa is not dangerous, and it’s easy to differentiate because they don’t have the ominous red shapes on the abdomen.
False Black Widow Range Map
False Black Widows are considered cosmopolitan species, which means they are common to find in and around homes. They prefer dark areas, such as under furniture or basement corners. These spiders normally don’t bite unless they are accidentally pinched or squeezed. But if you are bitten, they may potentially cause you some harm, unlike most spiders. Common symptoms include blistering, muscle spasms, pain, fever, sweating, and a general feeling of discomfort lasting for several days.
Here are two facts about False Black Widows that I found fascinating!
- Females can live up to six years! Males live shorter but still up to 1.5 years.
- As long as they have access to water, they can live several MONTHS without food.
#12. Noble False Widow
- Steatoda nobilis
- Their brown bulbous abdomen has cream-colored markings that resemble the shape of a skull.
- Females are 9.5 to 14 mm in size, while males are 7 to 11 mm.
- Individuals vary considerably in color and size.
This spider is an invasive species in Ireland, as it originates from Madeira and the Canary Islands.
Unfortunately, its population is still spreading, and it is considered one of the most invasive spiders in the world. Look for them both in and around your house. When the weather turns cold, these long-lived spiders (up to five years) retreat to the warm climate your home provides.
Noble False Widow Range Map
Noble False Widows get their name because of their resemblance to Black Widows and other venomous spiders. While they are not as dangerous to humans as Black Widows, their bite can be problematic. First, while the bite is painless, the release of venom into you causes intense pain and has been compared to receiving a bee sting, along with subsequent symptoms.
Second, these spiders carry pathogenic bacteria, which can cause an infection that is resistant to antibiotics. General symptoms from a bite include fever, general discomfort, and swelling. But luckily, bites are incredibly rare!
#13. European Harvestman
- Phalangium opilio
Also called Daddy-long Legs.
- Females have a body length of 6–9 mm. Males are slightly smaller at 4–7 mm. Legs are long and thin.
- The body has a three-lobed darker “saddle,” usually with spots or dashes.
- Single body region, only two eyes that do not see well.
Harvestman might be the most recognizable spiders in Ireland!
They are found in a wide range of habitats, including gardens, fields, hedgerows, lawns, green places in built-up areas, or even hiding underneath kids’ playground equipment. They are also very social, and it’s common to find them in large groups.
But here’s the crazy thing:
Even though harvestmen look like spiders, these arachnids are technically NOT spiders! They are in the Order Opiliones and have no venom, lack fangs, and do not bite.
In addition, they can swallow solid food, which allows them to eat small insects, fungi, dead organisms, bird dung, and other fecal matter. This trait differs from spiders that only eat their prey after turning them into a liquid.
Check out these other guides about animals found in Ireland!
Which of these spiders have you seen before in Ireland?
Leave a comment below!