What Do Spider Eggs Look Like? A Quick Visual Guide

As you venture into the realm of spider eggs, knowing what to look for is essential. Spider eggs come in various shapes, sizes, and colors depending on the species. You may find these tiny orbs of life clustered together in egg sacs, which are usually covered with silk to protect the developing spiderlings.

For instance, some egg sacs may resemble cotton balls, while others could look like small, delicate pouches. Most spider eggs are cream-colored or white, but there could be instances when they take on a brown or even faintly green hue. These unique characteristics differ from one species to another, making it important to observe them closely.

Remember, spiders play a crucial role in balancing ecosystems by controlling pest populations. By understanding their reproduction process through identifying their eggs, you not only contribute to preserving these fascinating creatures, but also deepen your knowledge of the intricate and diverse spider world.

Identifying Spider Eggs

Color and Texture

When identifying spider eggs, one of the first things to observe is the color and texture. Spider eggs can have various colors, but they are typically white, beige, or even a light brown. The texture of the eggs can also vary; some may appear smooth, while others might have a slightly rough or bumpy surface. For example, yellow garden spider eggs are placed in white, multilayered, teardrop-shaped egg sacs, suspended within the spider’s web.

Shape and Size

Another factor to consider when identifying spider eggs is their shape and size. Spider eggs are usually round or oval-shaped and can come in different sizes, depending on the species. The size of a spider egg can range from very tiny, like a pinhead, to larger, like a small marble. The shape and size of the egg sacs can also vary, as some spiders create elaborate sacs for their eggs.

Spider Species Egg Sac Shape Size
Yellow Garden Teardrop Small
Black-and-Yellow Argiope Round Medium to Large

Location

Lastly, considering the location of the eggs can help you identify which spider species they belong to. Spiders lay their eggs in different places, such as:

  • Inside a web, hanging from a tree or bush
  • Hidden in crevices or cracks of rocks or walls
  • Under leaves or logs

To identify spider eggs, you should pay close attention to the location where you discovered them. For instance, the black-and-yellow Argiope spider lays its eggs surrounded by a unique zig-zag pattern, usually found in the center of its orb-shaped web.

By taking note of these characteristics, you’ll be better equipped to identify spider eggs and the species they belong to.

Different Spider Species and Their Eggs

Wolf Spider

Wolf spiders carry their eggs using a sac attached to their abdomen. The sac is round and appears silk-like, containing multiple eggs within. When these eggs hatch, the spiderlings climb onto their mother’s back for protection.

Brown Recluse

The brown recluse spider lays 1-2 egg masses per year in dark, sheltered areas. Their egg cases are round, about 5/8 inch (1.6 cm) in diameter, flat on the bottom, and convex on top. Spiderlings emerge after 24 to 36 days.

Black Widow

Black widow spiders lay their eggs in a sturdy, round silk sac. These sacs are typically off-white, beige, or gray, and they may hold up to 250 eggs. The eggs hatch in about 14 days, and the spiderlings venture away from the sac not long after.

Garden Spider

Garden spiders, such as the Black-and-Yellow Argiope, lay their eggs in a cocoon-like sac. The sacs are usually found on the underside of leaves or hidden within vegetation. They can be flat or round, and often have a papery texture.

Jumping Spider

Jumping spiders create small, ovular silk sacs for their eggs. The sacs have a yellowish-brown or white color. The female spider usually guards the sac until the spiderlings hatch, ensuring their safety.

Hobo Spider

Hobo spiders build egg sacs using their unique funnel-webs. The sacs are typically brown, teardrop-shaped, and about the size of a dime. The female spider lays her eggs inside the sac and guards it until the spiderlings emerge.

Here’s a comparison table for easy reference:

Spider Species Egg Sac Shape Egg Sac Color Guarding Behavior
Wolf Spider Round Silk-like Carries on abdomen
Brown Recluse Round Off-white Guards in shelter
Black Widow Round Beige/gray None
Garden Spider Cocoon-like Papery None
Jumping Spider Ovular Yellowish Guards
Hobo Spider Teardrop Brown Guards in web

Understanding Spider Egg Sacs

Material of Egg Sacs

Spider egg sacs are made from silk that is produced by the spiders themselves. The silk is used to create a protective casing for their eggs and it varies in thickness and texture depending on the species. In general, egg sacs are lightweight, and you might find them in various shapes such as round, teardrop, or even flat, depending on the type of spider.

For example, the broad-faced sac spider constructs its egg sac with a thin layer of silk, making it delicate and easily torn. On the other hand, some other spider species like the black widow, create stronger and more durable egg sacs, tough enough to keep the eggs safe.

Identifying Different Egg Sacs

When it comes to identifying specific spider egg sacs, knowing their characteristic features can be quite helpful. Here are a few examples:

  • Black Widow: These spiders create smooth, round egg sacs that are off-white or beige in color. They can contain up to 400 eggs each.
  • Brown Recluse: These sacs are small, off-white, and flat, often found in dark, sheltered areas, such as the corners of your garage or basement.
  • Jumping Spider: Jumping spider sacs are small and spherical with a papery texture, and are usually well-hidden.

To give you a clearer picture, here’s a comparison table of different spider egg sacs:

Spider Species Shape Color Texture
Black Widow Round Off-white/beige Smooth
Brown Recluse Flat Off-white Smooth
Jumping Spider Spherical Varies Papery

Remember, it’s always best to observe spider egg sacs from a safe distance – some spiders may be defensive of their eggs and can become aggressive if they feel threatened.

Lifecycle of Spider Eggs

Spider eggs play a crucial role in the reproduction process of these fascinating creatures. When it’s time to reproduce, spiders lay eggs, typically in a safe and hidden location. The timeframe for when spiders lay eggs varies depending on the species, but it often occurs during warmer months when there is an abundance of food.

The eggs are enclosed in protective silk sacs that keep them safe from predators and environmental factors. In these sacs, the spiderlings, or baby spiders, begin their life journey. During this period, the spiderlings are vulnerable, and many factors can influence their survival. For instance:

  • Temperature fluctuations
  • Limited access to food resources
  • Predation from other animals

These small spiderlings undergo multiple molting stages before reaching adulthood. Molting is essential for their growth, as it allows them to shed their exoskeleton and develop a new one. The process of molting continues until they reach their full size and sexual maturity.

Spiders are known for their diverse behaviors and appearances. Here are a few fascinating facts about their eggs and spiderlings:

  • Some spider species carry their egg sacs with them to protect them from harm.
  • In certain species, the mother spider guards the egg sac until the spiderlings have hatched.
  • Female spiders can lay hundreds or even thousands of eggs at a time, depending on the species.

Throughout their lifecycle, spiders face many challenges to survive and thrive. As you encounter these fascinating creatures in nature, remember the intricate journey that begins with their humble egg sacs and leads to the skilled predators that play an essential role in our ecosystem.

Preventing and Treating Spider Infestations

Environment and Seasons

Spider infestations are more likely to occur in certain environments and seasons. In humid areas like basements and attics, spiders are more likely to build their webs. Additionally, spring and summer are the seasons when spiders are most active. To prevent infestations, consider the following:

  • Keep your environment dry and well-ventilated.
  • Seal cracks and gaps around windows and doors.
  • Regularly clean and declutter your space.

Getting Rid of Spider Eggs

If you discover spider eggs, it’s essential to act quickly to prevent a more significant infestation. Here are a few tips on how to get rid of spider eggs:

  • Vacuum the area where you found the eggs, including any nearby webs.
  • Dispose of the vacuum bag or contents securely to prevent the eggs from hatching indoors.
  • For a more thorough option, you can use a bleach solution to gently scrub the area where the eggs were found.

Pros:

  • Fast and efficient removal of eggs
  • Prevents the development of a larger infestation

Cons:

  • Requires regular vigilance to spot and remove eggs
  • Bleach can be harmful if not handled with care.

Professional Pest Control Options

If you have a persistent spider infestation or a large number of eggs to deal with, consider hiring a professional pest control service. They can offer:

  • Expert advice on the best methods for treating your specific infestation
  • Access to specialized equipment and chemicals to remove spiders and their eggs effectively

Remember, it’s essential to address spider infestations early, so be sure to monitor areas like your basement or attic regularly. Following these tips should help you keep your home spider-free and avoid more significant issues down the line.

Special Spiders’ Traits and Behaviors

Female Spiders and Egg Laying

Female spiders are known for their unique aspects when it comes to egg-laying. They often create secure egg sacs to protect their offspring. These sacs can be made of silk and can vary in shape, size, and color depending on the spider species. For example, the common house spider’s egg sac is round and beige, while the black widow’s egg sac appears more like a spiky ball.

When you come across spider eggs, you’ll typically notice the following characteristics:

  • Spherical or oval shapes
  • Neutral colors like white, beige, or brown
  • Covered in silk for protection
  • Found in concealed, safe locations

Ballooning Spiders

Ballooning is an incredible behavior exhibited by certain spiders, especially by young spiderlings or small species. They use their silk like a parachute to be carried by the wind and disperse to new locations.

In order to balloon, a spider will do the following:

  1. Climb to a high point like a tall grass blade or a branch
  2. Release a thin strand of silk from its spinnerets
  3. Let the silk catch the wind and lift the spider off the ground

Ballooning is both fascinating and beneficial. Here’s a quick comparison of its pros and cons:

Pros Cons
Allows spiders to find new habitats Can be risky and unpredictable
Helps spiders escape predators Not suitable for larger species
Allows for gene flow and genetic diversity Wind conditions must be optimal

Remember to look out for these amazing traits and behaviors when you’re observing spiders in your environment. Their unique abilities make them fascinating creatures to study!

Interactions with Humans and Predators

When you encounter spider eggs, it’s important to know how they might affect you and their predators in the environment. Spider eggs are usually small, white or yellowish, and found in silk sacs. Not all spiders are poisonous, but some species, like the black widow, can cause harmful lesions if they bite you.

In most cases, spiders and their eggs don’t pose a risk to humans. However, when you come across spider eggs, it’s good to be cautious and avoid touching them. Some spiders can be aggressive when they feel their eggs are threatened.

Knowing more about predators that feed on spider eggs may also help:

  • Some insects, such as parasitic wasps and mantids, are known to prey on spider eggs.
  • Birds and small mammals like shrews and mice may feed on spider eggs as well.

Here’s a quick comparison of relevant information:

Entity Interaction
Predators Insects, birds, and small mammals
Lesions Only some spider species, like the black widow, cause lesions through their bite
Poison Not all spiders are poisonous; if unsure, exercise caution when encountering spider eggs or when dealing with spiders in general

In summary,

  • Always be cautious when you encounter spider eggs
  • Understand the role of predators in controlling the spider population
  • Don’t touch spider eggs if you’re unsure whether they belong to a poisonous species or not

By being aware of these interactions, you can make informed decisions when dealing with spiders and their eggs in your environment.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Magnificent Spider Egg Sacs from Australia and adult Spider

 

Subject: Australian Inquiry
Location: Dorrigo, New South Wales, Australia
January 28, 2016 7:43 pm
Hello Bugman!
Im writing to you from Australia, the East Coast NSW. I have found this nest on my fathers property and its got us all puzzled. (Obviously, otherwise I wouldn’t be writing to you for help!)
Its a group of small nests/cocoons (?) suspended in an olive tree. you can see by the photo that there are seven sub-dwellings dangling down, each approximately 5-7cm (2-3″) and what you can’t quite see from the picture is that there is a egg/sphere-shaped object tucked up in the mass of leaves that are all swathed in that goldy-orange web. there has been no movement noticed to or from the nests, but over the 4 weeks we have noticed that a pinprick hole appeared overnight in only one of the seven nests top…(perhaps a visiting parasite, it didn’t look like an obvious entry/exit hole for the resident in question.) Other details are the 7 nests are hollow/hard paper sounding constructions. the web has carcasses of beetles and flies stranded in it – seemingly in a certain area above which indicates they have been eaten by a resident… thats about all the information I have… I do hope you can help out, curiosity is peaked as we wait and watch!
Signature: Kind Regards, Naomi Drage

Egg Sacs of the Magnificent Spider
Egg Sacs of the Magnificent Spider

Dear Naomi,
We are really enjoying researching your request.  Our initial impression that these resembled the Egg Sacs of Orbweaver Spiders proved to be correct when we discovered the Australian Museum page on the Magnificent Spider,
Ordgarius magnificus.  According to the Australian Museum site:  “Very little is known about the courtship and mating of Magnificent Spiders, but once egg development starts, the female’s abdomen swells up quite remarkably. She constructs a series of spindle-shaped egg sacs over several nights, and each one is filled with about 600 eggs. The egg sacs are attached to a branch, and may number up to seven. They are often parasitised by wasps and flies.  The mother spider usually dies off over winter. The baby spiders emerge in late winter to early spring and disperse by ballooning.”  The site also notes:  “During the day, the Magnificent Spider hides in a retreat made by binding leaves together with silk. Preferred trees include natives such as eucalypts in dry or wet sclerophyll forests, but these spiders are also found in suburban gardens. Often the spider’s characteristic spindle-shaped egg sacs are hanging near the retreat.”  The retreat is evident in the upper right hand corner of your excellent image.  Butterfly House also has some wonderful images and notes:  “These spiders are quite amazing. They catch their prey by creating a line of silk with a sticky blob on the end, then swinging it round and round. They emit the pheromones of some female moths to attract the male moths within range of their bolas, catching the moths rather like the Incas hunted game and the gauchos of Argentina catch their cattle.”  The Find a Spider Guide has a marvelous image of the Magnificent Spider and notes:  “The two yellow cones and red marbling on the dorsal surface of the abdomen of this spider are distinctive. Also very useful for identification purposes are the egg sacs. These are very large (about 5 cm long) and spindle-shaped, and hang in groups of about five.”  Your especially fecund female has produced seven egg sacs.  Thanks so much for providing our site with this wonderful posting for our archives.  Perhaps you will be able to get an image of the Spider herself.  She is undoubtedly the “egg/sphere-shaped object tucked up in the mass of leaves that are all swathed in that goldy-orange web” you mentioned.  The information provided on Arachne.Org may help you get that image which may require a flash on your camera.  Here is that information:  “These spiders are active at night, with a simple web in trees or tall shrubs, rarely less than 2 metres above the ground. Their presence is usually indicated by a cluster of large, brown egg sacs hanging among foliage. The egg sacs are conspicuous, up to 5 cm long – many are targeted by flies and wasps that parasitise spiders’ eggs. Up to 9 sacs may be made by a spider in a season, each with several hundred eggs. The male spiders mature within the egg sac, emerging with fully functional mating organs. At night the female spins a trapeze line from twigs above an open space in the branch or foliage. She hangs from this trapeze and spins into the space a short, single line of silk with a large droplet of very sticky silk, the bolas, at its end. The upper end of the line is held by the female’s second leg. The spider emits an airborne pheromone attractive to male moths of the family Noctuidae. Vibration sensitive hairs on the spider’s outstretched legs can sense the wing beats of an approaching moth. The spider begins to swing the bolas around in a circle beneath the moth until it is hit by the sticky bolas. It flutters in tethered flight while the spider hauls it in. The moth is then bitten, wrapped and either eaten or hung. Several moths may be caught in a night.”

Egg Sacs of a Magnificent Spider
Egg Sacs of a Magnificent Spider

Thats so great, thank you. Its an impressive (or magnificent!) looking creature! I look forward to getting out there at night and seeing if we can sight it! Will send you an update photo if we manage to catch it in action 🙂
There has been a change to the centre egg since I emailed, its sac surroundings have coloured in patches of rusty orange. So perhaps hatching will begin shortly!
Keep up the great work, thanks again!
Naomi Drage

Update:  February 10, 2016
Hello!
So our magnificent spider has been rather productive this week, she seems to have lost two of the spindle egg sacs to parasites (pinhole at top and sunken appearance), so she gone on and made an 8th one! Her markings are stronger now than they were before, and I can imagine being bird, poking your head up the nest hole and getting a terrible fright from her faux ‘serpent head’ abdomen! a great deterrent, even enough for me to keep good distance! hope the photos are a welcome addition for your gallery.
Regards, Naomi

Magnificent Spider in her lair
Magnificent Spider in her lair

Thanks for the update Naomi,
Your Magnificent Spider really does look like a serpent.

Update:  April 9, 2016
Hi!
I thought I’d update you on our “super-mama” magnificent spider that we have been watching – she has now exceeded her previous best and gone and made two new egg sacs!! she has ten in total now (with the australian museum website stating that 7 is normal, I’m cheering for our girl!) although she is still alive and well, the weather is cooling down so we expect her to die off soon. Her young are free-blowing away to neighbouring trees – I have included a picture of one of the offspring. You can see its perched near some orange seed-like balls… are they part of the web lure?
Because of the physical distance form my own home, I still haven’t witnessed the night-time feeding performance, simply being satisfied with day-time sightings!
Cheers, Naomi

Magnificent Spider Egg Sacs
Magnificent Spider Egg Sacs

Thanks for the update Naomi,
We especially enjoyed the image of the Magnificent Spiderling ballooning to a new location.  We are unsure of the identity of the orange features of the web.

Magnificent Spiderling
Magnificent Spiderling

Letter 2 – Egg Sac of Basilica Orbweaver

 

Spider Egg Chain?
Subject: Spider Egg Chain?
Location: baltimore md
November 27, 2010 7:09 pm
Baltimore on Wednesday, November 24. Rubbery strand running between two holly branches with chain of eggs suspended. Spider eggs?
Signature: karan

Basilica Orbweaver Egg Sacs in a row

Dear Karan,
We are very excited to be posting your letter and photo because our research has revealed three misidentifications on our website from many years ago.  In 2004, we received a similar image from Delaware that also pictured the spider.  At that time, there was not as much information on the world wide web, and we found information in text form in a Comstock Spider book that described the egg sacs of
Cyclosa bifurca, and we made our identification based on that information.  Then in 2006, we received a second similar image from Tennessee and again, we believed it to be the work of Cyclosa bifurca.  Today, while preparing to post your photo, we found images on BugGuide of the renamed Allocyclosa bifurca, and though the egg sacs bear a resemblance, they do not seem quite right, and the pictured spider is most obviously different from the spider pictured in our 2004 letter.  Heading back to BugGuide, we browsed through the possible Orbweavers and found the Basilica Orbweaver, Mecynogea lemniscata, that produces egg sacs in a row and looks exactly like the spider in our 2004 posting.  We can now correct our prior mistakes, citing your letter as the source of the journey to the revelation.  According to BugGuide:  “The female attaches eggsacs to each other vertically in her dome shaped web.

Wow, you’re the best!  I’ve just sent your email and link to all the family members who gathered for Thanksgiving. Basilica Orbweaver is a delightful name and we’re thrilled to have the ID. The eggs are right outside my parents’ house and we can look for generations of spiders to come.
Thank you, thank you!
Karan

Letter 3 – Egg Sacs of a Bolas Spider in Mount Washington

 

Egg Sacs of a Bolas Spider
Egg Sacs of a Bolas Spider

Subject:  Egg Sacs of a Bolas Spider
Location:  Mount Washington, Los Angeles, California
November 18, 2014
This weekend while working in the garden, I finally decided to pull out the camera and shoot the Egg Sacs of the Bolas Spider that lived on the pole in the garden all summer.

Egg Sacs of a Bolas Spider
Egg Sacs of a Bolas Spider

 

Letter 4 – Egg Sacs of Bird Dropping Spider in Australia

 

Subject: Cocoon identification
Location: Melbourne
May 10, 2016 10:17 pm
I found this on my Magnolia tree today. I am in Melbourne, Australia. I am interested to know what it is. I have removed it from the tree. It is currently Autumn.
Signature: Regards Sharon

Bird Dropping Spider Egg Sacs
Bird Dropping Spider Egg Sacs

Dear Sharon,
These look like the Egg Sacs of a Spider.  We found a matching image on Museum Victoria where it states:  “Another interesting feature of this spider is its egg sacs. Bird-dropping Spiders can produce up to 13 egg cases. They are dark brown with black markings and, when suspended in the web, look like a bunch of dark grapes. The female keeps watch over the egg cases until the young emerge, usually in late winter to early spring.”  The scientific name of the Bird Dropping Spider is
Celaemia excavata.  The adult Bird Dropping Spider is pictured on the Australian Museum site.

Letter 5 – Egg Sacs of a Bolas Spider

 

Subject: Ominous looking egg sacs
Location: Garden Grove, CA.
August 16, 2015 12:59 pm
Noticed these (11) egg sacs in our Aloe barberae tree, and I have never seen anything like them in my life. I haven’t found the mama yet, but after looking around I am guessing them to be from the Bolas spider. LOL, I was ready to call the State bug authorities and have them terminated, but from what I read, they are harmless moth eaters so I will let them be. They are still a bit scary to look at.
Signature: Gman

Bolas Spider Egg Sacs
Bolas Spider Egg Sacs

Dear Gman,
We agree that these are Egg Sacs of a Bolas Spider, and we concur that the adult Bolas Spider is harmless as well as being difficult to find as they resemble bird droppings.

Bolas Spider Egg Sacs
Bolas Spider Egg Sacs

Reader Emails

95946

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Bolas Spider Egg Sacs

 

Subject:  What is this?
Geographic location of the bug:  El Sereno, Los Angeles
Date: 10/06/2018
Time: 06:30 PM EDT
Your letter to the bugman:  This is hanging from my citrus tree. What is it?
How you want your letter signed:  Emily

Bolas Spider Egg Sacs

Dear Emily,
These are egg sacs of a Bolas Spider,
Mastophora cornigera, a harmless Orbweaver.  Here is a BugGuide image for comparison.  BugGuide also contains this bit of fascinating information:  “When egg sacs hatch they release immature females and *mature* males! Presumably an adaptation to avoid inbreeding. Males are short-lived and much smaller (obviously) than females.”  The eggs will hatch in the spring. 

Authors

    by
  • 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.

  • 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.

7 thoughts on “What Do Spider Eggs Look Like? A Quick Visual Guide”

  1. Thank you for the excellent, very informative response. Nice to know that on the opposite side of the planet (from Vancouver Island, BC Canada) the orb weavers are doing well. And that other people find them as fascinating as I do. Keep up the good work!

    Reply
  2. The amazing BBC documentary “Life in the Undergrowth” featured the Bolas Spider (I don’t know if it’s the same species, but it’s surely closely related) and has some wonderful footage of the spider in action. Here’s a YouTube clip (bolas spider starts at 3:00, though the earlier segment on the redneck spider is also interesting).
    https://youtu.be/bQABY9H1h1Y

    Reply
  3. The amazing BBC documentary “Life in the Undergrowth” featured the Bolas Spider (I don’t know if it’s the same species, but it’s surely closely related) and has some wonderful footage of the spider in action. Here’s a YouTube clip (bolas spider starts at 3:00, though the earlier segment on the redneck spider is also interesting).
    https://youtu.be/bQABY9H1h1Y

    Reply
  4. I found this today laying in our Childcare centre yard in Toormina this morning during yard check. It’s has been annoying me all day as to what may have lived in it. The children and I googled so many different little creatures that may have lived in it never thinking it would be a spider sac.

    Reply
  5. Took a few pictures tonight. I don’t know if they are anything like good enough for you, but they are on my facebook page, publicly, and you are welcome to a look. If any is useful to you, tell me, and I will send you the originals in high resolution form.

    Reply

Leave a Comment