Are Nursery Web Spiders Poisonous? Separating Fact from Fiction on Poisonous Claims

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Nursery web spiders are fascinating creatures that can be found near water edges and on shoreline vegetation.

These large spiders may appear intimidating, but many people wonder if they are actually poisonous to humans.

While nursery web spiders do possess venom, it is primarily used to kill their prey – including small fish.

However, the venom is not potent enough to pose a significant threat to people or pets.

So, despite their somewhat fierce appearance, nursery web spiders are not considered dangerous to most humans.

Are Nursery Web Spiders Poisonous
Male Nursery Web Spider

Are Nursery Web Spiders Poisonous?

Venom and Toxicity

Nursery web spiders belong to the family Pisauridae and do possess venom, which they use to immobilize their prey1.

However, their venom is not considered dangerous or toxic to humans. Compared to other venomous spiders, nursery web spiders pose a minimal threat.

Bite Effects on Humans

Bites from nursery web spiders are rare occurrences. When bites do happen, they are usually the result of the spider feeling threatened or disturbed2.

The effects of a nursery web spider bite on humans are typically mild and may include:

  • Temporary pain or discomfort
  • Slight redness or swelling at the bite site

Generally, these symptoms subside within a short period without any long-lasting complications3.

Comparison Table

CharacteristicNursery Web SpidersOther Venomous Spiders
VenomousYesYes
Dangerous to HumansNoDepends on the species
Bite SymptomsMildVarying degrees of severity

Bite Effects – Key Points

  • Nursery web spiders have venom
  • Their venom is not considered dangerous to humans
  • Bites are rare and typically result from disturbance or threat
  • Bite symptoms include temporary pain, redness, or swelling
  • Symptoms usually resolve quickly without complications

or more generally a Nursery Web Spider

Nursery Web Spider Biology and Behavior

Physical Characteristics

Nursery web spiders belong to the family Pisauridae. They have slender bodies and long legs, which help them blend in with plants or grass stalks.

Their size varies depending on the species, but they are generally medium to large-sized spiders.

Their bodies often have lengthwise striping in colors including shades of brown, black, gray, and white. Their carapace and chelicerae display various shades of brown or gray.

Habitat and Distribution

These spiders can be found in a variety of habitats, including:

  • Grasslands
  • Woods
  • Climbing on plants near water

Nursery web spiders are mainly distributed in North America. They are adaptable to different environments, which allows them to occupy diverse habitats.

Diet and Hunting Strategies

Nursery web spiders’ primary diet consists of insects. They employ different hunting strategies, such as:

  • Ambushing: They wait for their prey on plants or grass stalks.
  • Jumping: They can jump to catch flying insects like flies.

These spiders don’t spin webs to catch prey, which distinguishes them from other species like funnel web spiders and orb weavers.

Nursery Web Spider with Egg Sac

Comparison between Nursery Web Spider and Wolf Spider

FeatureNursery Web SpiderWolf Spider
Web constructionMinimal, nursery web onlyMinimal, no elaborate web
Active atDaytimeDaytime and primarily nighttime
Body markingsLengthwise stripingVaried, some may have striping
Hunting strategyAmbushing and jumpingStalking, chasing, grabbing prey
Care for offspringBuild protective nursery webCarry young on their back

Nursery web spiders exhibit fascinating behaviors related to reproduction. Female nursery web spiders build a protective nursery web to house their offspring.

The male nursery web spider often presents the female with a gift-wrapped insect as part of their courtship ritual before mating.

This behavior has not been observed in wolf spiders.

Reproduction and Life Cycle

Mating and Courtship Rituals

Nursery web spiders, specifically Pisaurina mira, have quite unique mating rituals.

The male nursery web spider offers the female a “gift” to increase his chances of successful mating.

The gift, typically a captured insect, is wrapped in silk and presented to the female spider.

During courtship, both spiders perform intricate behaviors which may involve:

  • Tapping on each other’s legs
  • Vibrations through the web
  • Confined movement around each other

Egg Sac and Parental Care

Female nursery web spiders exhibit exceptional parental care. After mating, the female will lay her eggs and create a protective egg sac.

They carry the egg sac with their fangs until it’s about to hatch. Key features of egg sac and parental care:

  • Female spiders create a cocoon-like structure called a “nursery” by weaving silk around leaves or shrubs
  • The nursery protects spiderlings from predators and harsh environmental conditions
  • Spiderlings stay in the nursery for a short period after hatching, then disperse to find their own territories

Nursery web spider bites are generally not dangerous to humans. However, they may cause localized pain and swelling.

Nursery Web Spider with Egg Sac

Comparison between Pisaurina mira and Dolomedes (raft spiders):

FeaturePisaurina miraDolomedes
Parental CareHighModerate
Active HuntersYesYes
HabitatLand, shrubsNear water
Courtship giftYesNo
SunbathingYesNo

Overall, nursery web spiders are fascinating creatures with unique courtship rituals and a strong parental instinct. Although their bites can be painful, they are generally harmless to humans.

Surviving and Avoiding an Unwanted Encounter

Do’s and Don’ts Around Nursery Web Spiders

Nursery web spiders belong to the family Pisauridae and are commonly found in the woods or near their habitat.

These spiders are not toxic to humans, but it’s still best to practice caution when you come across them. Here are some do’s and don’ts:

  • Do observe them from a safe distance, as they might feel threatened if you come too close.
  • Don’t disturb their habitat or try to handle the spiders directly.
  • Do keep your outdoor areas well-maintained to minimize spider encounters.
  • Don’t panic if you come across a nursery web spider. Remember, they pose no significant threat to humans.

First Aid for Nursery Web Spider Bites

Although nursery web spiders are not toxic, their bites can be painful and might cause an allergic reaction in some individuals. If you are bitten, follow these steps:

  1. Clean the bite area with soap and water.
  2. Apply a cold compress to reduce swelling.
  3. Avoid scratching or rubbing the area, to prevent infection.
  4. Take over-the-counter pain relievers and antihistamines for relief.

Here is a comparison table of some features of nursery web spiders versus other common spider species:

FeatureNursery Web SpiderBrown RecluseOrb Weaver
Toxic to humansNoYesNo
HabitatWoods, near waterDark, secluded areasGardens, near plants
MoltingYesYesYes

Remember, nursery web spiders are a part of our ecosystem and play an essential role in controlling the population of other insects. Treat them with care, and maintain a safe distance to avoid any unwanted encounters.

Footnotes

  1. Nursery Web Spider (Family Pisauridae) – Field Station

  2. Spiders in and Around Homes | NC State Extension Publications

  3. Spider Management Guidelines–UC IPM

Conclusion

To wrap things up, when it comes to nursery web spiders, they do have a kind of poison they use to catch their food.

But this poison isn’t dangerous to people.

These spiders have fascinating maternal instincts that are seldom found in the animal kingdom.

Knowing about their lack of poison and their role in nature can help keep them from harm and you safe.

Just remember, like with any spider, it’s good to give them their space and not bother them.

Authors

  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

    View all posts
  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

    View all posts
Tags: Nursery Web Spider

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5 Comments. Leave new

  • Looks a lot like some of our Argiope species.

    Reply
    • Thanks Trevor,
      We are pretty certain this is a Nursery Web Spider, and probably a White Banded Fishing Spider.

      Reply
  • Awww! I think there’s a brown nursery webber who likes to hang around outside my front door, I say hi to her every night 🙂

    Reply
  • Also, it might be helpful to post a link to what a Brown Recluse ACTUALLY looks like, as the misconception that any small to mid-sized spider that happens to be brown is a Recluse causes a lot of unnecessary carnage to beneficial spiders like that one.

    Here’s one of the best ID photos (I think) that you’ve posted:
    http://www.whatsthatbug.com/2008/02/25/brown-recluse-2/

    The key, as my outdoorsman father taught me, is to look for hair on the legs. If it has a noticeable growth of hair, you *know* it’s not a Recluse. Just scoop it up and take it outside.

    Reply

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