Orb weaver spiders are a diverse group of arachnids known for their intricate webs and fascinating behavior.
Many people wonder if these spiders are poisonous, which is a common concern when encountering spiders in general.
In reality, orb weaver spiders do possess venom, but it is not harmful to humans. Their venom is primarily used to immobilize their prey, such as insects.
When it comes to human safety, the bite of an orb weaver spider is usually considered mild and rarely requires medical attention.
Orb Weaver Spiders: An Overview
Orb Weaver spiders belong to the family Araneidae and are a diverse group of arachnids.
They are known for their intricate webs and can be found across North America, Mexico, and Canada.
These spiders vary in size, with female adult Marbled Orbweavers measuring between 9 to 20 millimeters in length.
The orb web is a distinctive feature of this group, though some vary greatly in appearance.
Some examples of orb weaver spiders include:
- Marbled Orbweaver
- Basilica Orbweaver
- Garden Orbweaver
Orb weaver spiders are not considered dangerous to humans. They may bite if threatened or handled, but their venom is not harmful to people.
Features of orb weaver spiders are:
- Large, rounded abdomens
- Intricate, wheel-like webs
- Presence in various habitats
An interesting fact: Orb Weaver spiders can detect sound by using their webs as an acoustic antenna, amplifying the sound-sensitive surface area up to 10,000 times their size.
This table illustrates key characteristics of the orb weaver family:
Characteristic | Description |
---|---|
Size | 9-20 mm in length |
Distribution | North America, Mexico, Canada |
Webs | Wheel-like, intricate |
Venom | Not harmful to humans |
Are Orb Weaver Spiders Poisonous or Venomous?
Effects on Humans
Orb weaver spiders are not poisonous and generally pose little threat to humans. Their bites may cause some discomfort like:
- Temporary pain
- Swelling
However, the effects are usually mild and no serious medical issues arise from their bites.
People with allergies could experience a stronger reaction, but it’s still not life-threatening.
Comparisons to Other Spiders
Orb weaver spiders are much less dangerous than other spiders like the black widow and brown recluse. A comparison table regarding key venom-related features:
Spider | Venomous | Chelicera & Fangs | Bite Effects on Humans |
---|---|---|---|
Orb Weaver | No | Small/Medium | Mild pain, swelling |
Black Widow | Yes | Medium/Large | Severe pain, cramping |
Brown Recluse | Yes | Medium/Large | Necrosis, severe reaction |
Orb weavers are usually:
- Non-aggressive
- Docile
- Harmless to humans
In comparison to more dangerous spiders, orb weavers are the safer option for humans to encounter, given their lack of venom and mild effects upon biting.
Physical Characteristics and Behavior
Size and Color Variations
Orb weaver spiders exhibit a range of colors, including:
- Yellow
- Brown
- Orange
- Gray
The size of orb weavers may vary, but typically female spiders are larger than males.
For example, the black and yellow orb weaver spider has females that grow up to an inch in size, while the males are much smaller.
Web Construction
Orb weaver spiders are known for their intricate web designs, which they use to trap prey.
They construct their webs primarily using silk produced from their abdomen. Key features of orb weaver webs:
- Orb-like structures
- Anchored by strong outer threads
- Densely spun spiral pattern
These spiders are able to recognize the vibrations produced when prey interacts with their web, allowing them to quickly respond and capture their next meal.
Mating and Reproduction
The mating process for orb weavers involves a unique approach from male spiders.
They approach the female’s web carefully, often sending signals through the web to avoid being mistaken as prey.
After mating, the female produces egg sacs, which can contain hundreds of spiderlings.
Here’s a brief comparison table of male and female orb weavers:
Characteristic | Males | Females |
---|---|---|
Size | Smaller than females | Larger than males |
Role | Mating | Web construction & mating |
Lifespan | Shorter | Longer |
In conclusion, orb weaver spiders display a variety of physical characteristics and behaviors that make them easily recognizable.
They are not considered poisonous, and though their appearance may be intimidating to some, they play an important role in controlling insect populations in their environment.
Habitat and Distribution
Orb weaver spiders can be found in various environments, including:
- Gardens: They are commonly seen in gardens, providing natural pest control by capturing insects.
- Bushes: Orb weavers build their intricate webs in bushes for camouflage and better access to prey.
- Trees: They also inhabit trees as they offer a great structural support for their webs.
- Tall grass: In tall grass, orb weavers can build expansive webs to catch a variety of insects.
The distribution of orb weaver spiders is vast.
They reside in every continent except for Antarctica, but are not found in extreme environments like Alaska or Hawaii.
There are many genera and species of orb weaver spiders with unique characteristics, such as:
- Marbled orbweaver: Mostly orange with brown to purple markings, and found in North America.
- Barn spider: This spider has a wide range of colors, and its web consists of concentric circles and radiating lines, as seen in the Araneidae family.
- Cross orbweaver: Displaying a yellow to brown background color, these spiders have wavy lines and elongated spots.
Below is a comparison table of the species mentioned above:
Species | Colors | Web Pattern | Size | Region |
---|---|---|---|---|
Marbled orbweaver | Orange, brown, purple | Orb | 9-20mm | North America |
Barn spider | Various | Circles, lines | 1/8-1 inch | Global |
Cross orbweaver | Yellow, brown | Orb | Small | Global |
Feeding Habits and Prey
Orb weaver spiders are hunters known for feeding on various types of small insects. Their diet includes:
- Insects
- Flies
- Mosquitoes
- Moths
- Beetles
These spiders build intricate webs to capture their prey. Once an insect is trapped, the orb weaver quickly moves in to subdue it.
An interesting aspect of their hunting technique involves paralyzing their prey with a toxic bite before wrapping it in silk.
Orb weavers take down even larger prey if it gets caught in their webs source.
A comparison of orb weaver spiders’ prey preferences:
Insect Type | Frequency in Diet | Attraction to Web |
---|---|---|
Flies | High | Strong |
Mosquitoes | Medium | Moderate |
Moths | Medium | Moderate |
Beetles | Low | Light |
Orb weaver spiders do not pose a threat to humans. Their venom is not considered harmful to people source.
Creating a welcoming environment for orb weavers can actually benefit humans, as they help reduce the number of pesky insects around homes and gardens.
Beneficial Roles and Pest Control
Orb weaver spiders play important roles in gardens and ecosystems. They help control pests by feeding on insects that harm plants.
Some common garden pests that orb weavers eat are flies, mosquitoes, and beetles1.
Beneficial garden spiders like the orb weaver are not dangerous to humans. They are not poisonous and do not pose a significant threat to people or pets.
Instead, orb weavers provide natural pest control and can keep your garden thriving2.
Pros and Cons of Orb Weavers in Gardens:
- Pros:
- No need for harmful pesticides
- Help maintain a balanced ecosystem
- Naturally control pests
- Cons:
- Might scare some people
- Can create webs in inconvenient locations
- Not as effective as a professional pest control company
If pest issues persist or become overwhelming, it may be wise to contact a professional pest control company.
They have the expertise to manage pests more efficiently, using targeted methods3.
In conclusion, orb weaver spiders are beneficial creatures that provide natural pest control in gardens.
They are not poisonous and can help maintain a balanced ecosystem.
Prevention and Control Measures
Orb weaver spiders are generally not considered poisonous or dangerous to humans.
However, as with any spider species, if they become a nuisance, you may want to take some preventive measures to control their populations.
Prevention is key to managing orb weaver spiders. Some helpful tips include:
- Regularly clean your indoor and outdoor spaces, especially hidden corners and crevices.
- Make sure window and door screens are tight-fitting to prevent spiders from entering your home.
- Trim back vegetation near the exterior of your building to discourage spiders from building webs.
It’s important to keep in mind that orb weaver spiders can be beneficial, as they help control populations of other, more harmful pests.
For example, banana spiders are a type of orb weaver known for their large, intricate webs that can help reduce insect populations.
When compared to other spider species, orb weavers are generally less of a concern:
Spider Type | Level of Concern | Poisonous | Diurnal | Nusiance Pest |
---|---|---|---|---|
Orb weaver Spider | Low | No | Yes | No |
Black Widow | High | Yes | No | Yes |
Brown Recluse | High | Yes | No | Yes |
Remember that not all orb weaver spiders are the same. Some, like the trashline orbweavers, are diurnal and more likely to be seen during the day. They exhibit unique behaviors:
- Camouflaging their web with debris, creates the appearance of a “trash line.”
- Vibrating or jiggling their web in response to disturbances.
In conclusion, while orb weaver spiders may be unwanted guests in some homes, they rarely pose a threat and can even be beneficial in controlling other pests.
Notable Examples and Identification
Golden Orb Weaver
- Common name: Golden Orb Weaver
- Scientific name: Nephila
- Habitat: Tropical and subtropical regions
- Web: Large, golden, orb-shaped
The Golden Orb Weaver is a large, colorful spider in the family Nephilidae. It is known for its golden, orb-shaped web and unique appearance.
These spiders are not considered dangerous to humans, as their venom is relatively mild.
Black Widow
- Common name: Black Widow
- Scientific name: Latrodectus
- Habitat: Temperate regions worldwide
- Distinctive mark: Red hourglass on abdomen
The Black Widow is a small, black spider with a distinctive red hourglass shape on the underside of its abdomen. It is a member of the family Theridiidae. While their venom is dangerous, bites are rare and fatalities are extremely uncommon.
Golden Orb Weaver | Black Widow | |
---|---|---|
Venom potency | Mild | Dangerous |
Bite frequency | Rare | Rare |
Fatalities | Uncommon | Extremely rare |
Brown Recluse
- Common name: Brown Recluse
- Scientific name: Loxosceles reclusa
- Habitat: United States, primarily in the Southeast
- Distinctive mark: Violin-shaped mark on cephalothorax
The Brown Recluse has a violin-shaped mark on its cephalothorax and is native to the southeastern United States. Its venom can cause serious tissue damage, but bites are rare.
Wolf Spider
- Common name: Wolf Spider
- Scientific name: Lycosidae
- Habitat: Worldwide, in various habitats
- Distinctive features: Large, hairy, good vision
The Wolf Spider is a large, hairy spider in the family Lycosidae. They are found worldwide in a variety of habitats. While they may appear intimidating, their venom is not dangerous to humans.
Brown Recluse | Wolf Spider | |
---|---|---|
Venom potency | Dangerous | Mild |
Bite frequency | Rare | Rare |
Fatalities | Uncommon | Uncommon |
In summary, although some orb-weaver spiders like the black widow and brown recluse can have dangerous venom, others like the golden orb weaver and wolf spider pose minimal threat to humans.
Interesting Facts and Trivia
Orb-weaver spiders are fascinating creatures. Here are some interesting facts about them:
- They have 180 species worldwide, making them diverse and widespread.
- Their webs can span up to 3 feet in diameter, resembling a wagon wheel.
- They build their webs using concentric circular strands, creating a unique pattern.
- They’re mostly active in late summer, when their prey, like insects, is most abundant.
Orb-weaver spiders are not considered dangerous to humans.
Their venom is similar to a bee sting, which can cause mild pain and swelling but is rarely harmful.
Some examples of orb-weaver spiders include:
- The Darwin’s Bark Spider, known for its incredible web-spinning abilities.
- Garden orb-weavers, commonly found on tree branches, fences, walls, and weeds.
These spiders have natural predators, like wasps, which can prey on them.
When comparing orb-weaver spiders to other spiders, here are the main differences:
Feature | Orb-Weaver Spiders | Other Spiders |
---|---|---|
Web Shape | Circular | Varies |
Activity Period | Late Summer | Varies |
Web Size | Up to 3 ft | Smaller or Larger |
To sum it up, orb-weaver spiders are amazing arachnids, recognized by their large, circular webs and their impressive diversity. They’re mostly harmless to humans, with a venom similar to a bee sting.
Footnotes
Conclusion
While these spiders do possess venom to immobilize their prey, the majority of orb weaver species are not considered harmful to humans.
Their delicate and intricate webs contribute to ecosystem balance by controlling insect populations.
Acknowledging the venomous nature of orb weavers within the context of their ecological significance allows us to foster a deeper respect for these remarkable weavers of nature’s tapestry.
Remember, appreciating these spiders from a distance and letting them continue their vital work undisturbed is the key to peaceful coexistence.
Reader Emails
Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about Orb Weaver spiders. Scroll down to have a look at some of them.
Letter 1 – Asian Spiny Backed Spider from Hawaii
Spider, I think
February 10, 2010
Saw another one just like this about twenty yards away. Both in spider webs. So I think it’s a spider. Date was Friday, February 5, 2010. Weather clear. WHAT IS THIS???
Robert Lutman
Heritage Gardens, Wailuku, Maui, HI.
Hi Robert,
This is a spider, and more particularly, it is an Orbweaver, though we are not certain of the species. We will continue to research this unusual find. Additional research on the Hawaiian Bugs page of BugGuide revealed that this is a species we receive with great frequency, Gasteracantha cancriformis, the Crablike Spiny Orbweaver, though we have never seen this color variation.
Perhaps it is specific to Hawaii, where an isolated population may have diverged noticeably from its closest relatives on the mainland. The more commonly seen color variations are posted to BugGuide, which indicates additional common names for this species: “Spinybacked Orbweaver, Crab Spider, Spiny Orbweaver Spider, Crab-like Orbweaver Spider, Crab-like Spiny Orbweaver Spider, Jewel Spider, Spiny-bellied Orbweaver, Jewel Box Spider, Smiley Face Spider.”
We rarely doubt BugGuide, but in this case we were having problems, so we decided to continue to research this spider by searching for the species in Hawaii. We found an Organisms of Hawaii website that included another member of the genus, Gasteracantha mammosa, and those photos posted online are a direct match to your spider.
The Insects of Hawaii website lists this species as the Asian Spiny Backed Spider. The Guide to Common Singapore Spiders refers to this species as the Double Spotted Spiny Spider. The Hawaiian Biological Surveys section of the Bishop Museum Website also calls Gasteracantha mammosa the Asian Spinyback Spider, and indicates it is native to India and Sri Lanka, and that it was introduced to Hawaii in 1985.
The museum gives it a “bad guy” frown face because of its non-native status, and indicates: “This spider is more harmless than it looks. It builds a typical spider web but can cause some annoyance to those who accidentally walk into their webs that are strung up across trails and in between trees. It is uncommon on O`ahu because of the introduced red-vented bulbul (also from India), which is its natural predator. In Hawai`i, the bulbul (see card no. 26) is found only on O`ahu.”
Letter 2 – Basilica Orbweaver Egg Sac, not Cyclosa bifurca
third and final unknown for the day
This is the third unknown object found on a japanese maple today in Memphis, Tennessee. Is this an egg sac? It’s about an inch long and is suspended by a thin thread that spanned at least a foot between 2 branches.
Thanks,
Tim
Hi Tim,
This is a Spider Egg Sac. We have an old text that identifies eggs of this type as belonging to Cyclosa bifurca, but we believe that name may have been changed.
Correction
November 28, 2010
Today we received a new identification request which led us on an identification search on BugGuide that ended with a new identification for this egg sac configuration: the Basilica Spider, Mecynogea lemniscata.
Letter 3 – Golden Orbweaver
Yellow and Black, Scarry looking bug in friend’s backyard
August 20, 2009
My friend sent me the attached picture of a black/Yellow sorta striped bug from her back yard. 2 questions….1. Is it poisonous or does it “bite”. (she has 3 children and watches my 3 when I’m at work.) 2. What is it?
Christina J. Kuckie
lockport, IL
Dear Christina,
You aren’t worried about this beautiful Golden Orb Weaver being a thief? It is also called a Black and Yellow Garden Spider, Argiope aurantia, the spider from Charlotte’s Web. All spiders have venom, but very few will bite people and even fewer are dangerous. The Garden Spider minds its own business and stays in it web. It is not aggressive.
Letter 4 – Argentine Ants eat dead Orbweaver
Subject: Invasive Argentine Ants
Location: Mount Washington, Los Angeles, California
August 27, 2016
Dating back to our relocation to Los Angeles in 1980, the editorial staff of What’s That Bug? has been plagued by colonies of invasive Argentine Ants, Iridomyrmex humilis. If we had the time to devote ourselves to the elimination of one invasive species in California, it would be the Argentine Ant.
They are a pervasive pest species that we have always believed are the same Ants that play such an important role in the magnificent 20th Century novel “One Hundred Years of Solitude” by Gabriel García Márquez when they carry off a newborn baby.
Argentine Ants are most troublesome in the summer, during the hottest days when they enter homes to find water, but swarm around cat food, any sweets or fatty foods left out, or any dead bugs that ended their lives as cat toys. We believe they are one of the biggest threats to native species wherever they proliferate. According to Clemson University: “Argentine ants are not native to the United States.
They were introduced to the US probably on coffee ships from Brazil and Argentina through the port of New Orleans sometime before 1891. They spread rapidly on commercial shipments of plants and other materials. Now Argentine ants are found throughout most of the southern states and California, with isolated infestations in a few other areas.
Argentine ants have been very successful. They are common in urban areas and can nest in diverse types of habitats. They can produce large numbers of offspring and survive on a wide variety of food. They often live on friendly terms with other neighboring colonies of the same species, but may eliminate some other ant species.”
Argentine Ants farm Aphids and move them from plant to plant. We have also found Argentine Ants associated with other pestiferous Hemipterans that secrete honeydew. We would love to hear any control methods our readers can provide. Wayne’s Word also has some interesting information, including: “Best Method Of Argentine Ant Eradication Place outdoor ant bait stations such as Terro® along major ant trails in your yard.
This is probably better than using insecticidal sprays. Smaller, indoor bait stations are also effective placed along ant trails in your home (out of the reach of children and pets). The active ingredients of Terro® is 5.40 percent sodium tetraborate decahydrate (Borax) which is lethal to ants. This salt upsets their digestive system and causes death due to dehydration and starvation.
According to Jonathan Hatch (“How to Get Rid of Argentine Ants” ), dehydration and recrystallization of the ‘boric acic’ (borax?) lacerates the digestive system of ants and their larvae. There are many recipes on the Internet that include mixing borax with a sugary solution. Terro bait stations contain this mixture in convenient disposable plastic trays.
It is important for the ants to carry the liquid back to their nest. Borax recipes only contain about 5 percent borax so that ants are not killed immediately. One tablespoon of borax in a cup of water is approximately a 5% solution. You must be patient–this treatment may take several days to a week. In fact, you may need to replenish you bait stations!
Some websites state that boric acid is a more effective ant insecticide, but this is debatable. Boric acid is made by reacting borax (sodium tetraborate decahydrate) with an inorganic acid, such as hydrochloric acid (HCl).”
WE cannot say for certain if the Argentine Ants played a role in the death of this Orbweaver, but since Orbweavers are somewhat helpless when they are not in their webs, it is possible that this large spider was overcome by marauding Argentine Ants and killed.
Letter 5 – Banded Orbweaver
Subject: Siver-ish Giant Spider?
Geographic location of the bug: Eastern Ohio
Date: 09/29/2021
Time: 03:44 PM EDT
Your letter to the bugman: There’s this very big scary spider outside my house, what is it?
How you want your letter signed: Cidrew
Dear Cidrew,
This is a Banded Orbweaver, Argiope trifasciata, which is pictured on BugGuide. Like other Orbweavers, they are not considered dangerous to humans. Most Spiders have venom, and the venom is used to subdue prey, but very few Spiders have venom that is strong enough to adversely affect people. Orbweavers rarely bite, but in the rare occasions when a bite occurs, it will only produce a localized soreness near the bite area.
Letter 6 – Classic Orb
Returning Spider
Hi Bugman!
I learned about your site from a friend and have really enjoyed all of the great pictures. Now, I find that I have a question of my own. For the past two weeks, a spider has found a home in our backyard. It builds a web every night and it is gone the next morning.
The web consists of a single strand that stretches across the entire yard, a span of about 25 feet! The web, as shown in the photo, is then built off of this strand, and sits in the center of the yard and is attached to the ground. The spider, also shown below, hangs in the center of the web, and seems to be very nervous around people; he once crawled out of sight when one of us got too close.
We also found smaller spiders of the same kind building webs in nearby plants, there were a total of six spiders. We have enjoyed seeing our spider each night and would really like to know what kind it is. Thank you for your consideration.
Signed,
Curious Spider Watcher
Southern California
Dear Curious,
There isn’t much detail in the spider, but that is a gorgeous classic Orb Web. This Orb Weaver is probably an Araneus, like a Jeweled Araneus, Araneus gemmus.
Letter 7 – European Orbweaver
Argiope bruennichi
I saw you already have one Argiope bruennichi onsite, but this one was beauty. It took up residence in our garden last summer (Slovenia), stopping harvest for a while, then got bored and moved over the the side of the house where I got the underside shot. It was easily 3 times larger than any other spider I have ever seen.
James
Hi James,
Thanks for contributing another photo of this European Orbweaver, Argiope bruennichi, to our site. We have 10 archived spider pages and this will improve our readership’s chances of identification should they happen to encounter this large harmless species.
Letter 8 – Alaskan Orb Weaver
Help ID’ing spider?
I think this may be some type of Orb Weaver spider, but I am not sure. The markings are different from every picture I’ve seen, and I’ve gone through enough pics to give myself nightmares for a year. She lives under the eaves of my mom and dad’s house, hides during the day and is out on a web at night. I’d say about an inch and a half in size. Any information you could give me would be greatly appreciated. Thanks,
Jennifer
Kenai, Alaska
Hi Jennifer,
Yes, an Araneas Orb Weaver. Nice coloration. There is often much variation within individual species. This coloration looks like it mimics bird droppings which probably contributes to longevity.
Letter 9 – Courting Orbweavers
Spider Couple in the dew
Location: Southernmost Ohio
September 16, 2011 7:52 am
I took a visit to Southern Ohio, and while my goal was to look for snakes that we do not have in Northern Ohio where I hail from, my camping buddy and I ended up getting terribly sick and did not leave the campsite.
This did allow me plenty of time to laze around and look for spiders though, and this must have been Orb Weaver city; Found so many! Most of them were easy to identify, but this guy and gal (I suppose I don’t know for sure that they are of the same species…) I am not so sure of.
Probably didn’t help that I didn’t think to get a photo from the front! As always, love your website. Not only informational, but highly entertaining 🙂
Signature: Katy
Hi Katy,
WE are sorry to hear that your camping trip did not turn out as planned, but we are very happy to post your fascinating photo. We agree that this is most likely a pair of Orbweavers, with the female on the left. She has a very distinctive profile, and we have identified similarly shaped spiders in the past, but we are not having any luck identifying your species on BugGuide. Perhaps our readership will have better luck at an identification than we have had.
Letter 10 – Basilica Orbweaver, not Cyclosa bifurca
bugs!
First, let me say that I stumbled upon you site today, searching for buggy information, and found it fascinating. I am an amateur photographer, and ‘bugs’ are often my main subject.
You mentioned that you could not find any photos of Cyclosa bifurca. I have three photos that I thought you may enjoy seeing. You are welcome to use these photos if you wish.
I am still working on my photos project, but my collection (so far) can be found at http://www.rediware.com/pictures/pictures.htm in the ‘backyard life’ section. At present I have not identified my bugs, but you will find the quality pretty good.
Steve
Hi Steve,
Thanks for sending your awesome images our way.
Correction
November 28, 2010
Today we received a new identification request which led us on an identification search on BugGuide that ended with a new identification for this egg sac configuration: the Basilica Orbweaver, Mecynogea lemniscata. This incorrectly identified spider appears to also be the Basilica Orbweaver. The dome shaped web is quite noticeable in these images.
Letter 11 – Gasteracantha elipsoides: “Come Into My Parlor”
Spiny-back orb weaver
Hi – just wanted to add to your spiny-back orb weaver collection. Wish I had known about this site last year when I first found this guy and didn’t know what he was! Decided to feed him anyway and got some pics. Enjoy!
Gregory
Hi Gregory,
What a nice photo of the Crablike Spiny Orb Weaver.
Ed. Note: August 16, 2011
This spider is more commonly classified as Gasteracantha cancriformis. See bugguide.
Letter 12 – How to Help Kids get over their fear of Bugs
September 25, 2013 3:49 am
Hi Daniel,
We at Summernanny.com recently came across your blog and were excited to share with you an article “HOW TO HELP KIDS GET OVER THEIR FEAR OF BUGS” was recently published on our blog at (http://www.summernanny.com/blog/how-to-help-kids-get-over-their-fear-of-bugs/), and we hoped that you would be interested in featuring or mentioning it in one of your posts.
Either way, I hope you continue putting out great content through your blog. It has been a sincere pleasure to read.
Thanks for your time,
Emma Roberts
Signature: Emma Roberts
Hi Emma,
We are happy to link to your article, but it has been our experience that kids are often naturally curious about bugs and it is frightened parents that need to be educated. This little lady appears to be enthralled with the Golden Orbweaver.
Hi Daniel,
It’s really my pleasure sharing article with you, Thanks for posting & for your valuable thoughts.
Thanks again,
Emma
Letter 13 – Bird Dropping Mimic Spider from Indonesia
Subject: smooth and fluffy abdomen
Location: Situ Cileunca, Warnasari, Pangalengan, West Java, Indonesia
December 6, 2012 5:18 am
I took this photo on 11/27/2010.
This spider have a heart shaped abdomen with two equal circle pattern on each sides, and when you touch it it’s really smooth and fluffy feel like :).
I wonder what spider is it.
Signature: Mohamad Idham Iskandar
Hi Mohamad,
This also looks to us like an Orbweaver. Perhaps one of our readers will have better luck with a species identification of your two spiders. Since Orbweavers do not hunt, they do not have the keen eyesight that hunting spiders like Jumping Spiders have. The eye pattern on this individual also resembles the eye pattern of Orbweavers.
Thanks again Daniel, after reading some web materials especially from it’s eye arrangement I agree that this is an orb weaver although I didn’t see their orb when I took the photo’s.
I really Love your site.
Thanks for the compliment Mohamad. You have some amazing looking “bugs” in Indonesia.
Identification courtesy of Karl
Hi Daniel and Mohamad:
I believe the genus of your orbweaver is Cyrtarachne, a group that is usually described as bird dropping mimics, or sometimes snail mimics. Looking at several checklists for spiders of Indonesia it appears that there is only one species of Cyrtarachne reported from java, that is, C. perspicillata. Unfortunately, I could find no online photos. Regards. Karl
Wow, good job of sleuthing Karl. Thanks much.
Mohamad writes back
December 10, 2012
Thank you so much for the ID Karl, after searching about Cyrtarachne in Indonesia I only came up with only one pic of it 🙂
Cyrtarachne-bufo_Kadugede
At last I found this interesting site on flickr that have some photo of Cyrtarachne
cyrtarachne_Interesting
Letter 14 – Humpbacked Orbweaver
Subject: Weird spider!
Location: Dawsonville, GA
April 30, 2017 6:47 pm
Who is this dude? Dawsonville, Ga.
Thanks!!
Signature: Heather Tierney
Dear Heather,
This is one of the Orbweavers in the family Araneidae, and it has rather distinctive markings, so we decidedc to try to make a species identification.
That is sometimes a challenge with Orbweavers because sometimes several species look very similar, but even more challenging is that sometimes one species will have multiple color and marking variations.
We found a very close match on BugGuide that is identified as a Humpbacked Orbweaver, Austala anastera, and BugGuide does indicate: “anastera has 6 basic patterns” and most of the submitted images look nothing like your spider.
Letter 15 – Golden Silk Orbweaver from Guinea
Subject: spider in Equatorial Guinea
Location: Equatorial Guinea
June 2, 2014 7:39 am
Found spinning huge webs on a fence in the rainforest in May was wondering if it was a golden web orb spider maybe?
Thanks
Signature: susan
Dear Susan,
We tried to identify this Orbweaver in the family Araneidae, and we did not have any luck. So it is an Orbweaver, but we cannot provide a species name at this time.
Thank you, it is a beauty but glad it was outside and not in my cabin!
Karl provides an identification
Hi Daniel and Susan:
This is a Golden Orbweaver or Golden Silk Orbweaver in the genus Nephila (family Nephilidae, probably N. turneri, which occurs throughout west and central Africa. Regards. Karl
Letter 16 – “Blind Eyed” Orbweaver from Virginia
Subject: Name That Nope!
Location: Chesapeake, Virginia
May 20, 2016 2:26 pm
I found this neat little guy running around my smoker 2 days ago (May 18, 2016). I live in Chesapeake, VA. I’ve reached out to the internet via Facebook and Imgur as well as searched through a spider database i found with no matches. Suggestions were a Juvenile Orb Weaver (which we’ve had a few of over the years) or theridion grallator.
Signature: -Anthony T.
Dear Anthony,
Orbweaver is a general name for a Spider from the family Araneidae and according to BugGuide: “There are approximately 3,500 species worldwide, with 180 occurring north of Mexico.”
But for the eerie pair of blind eyespots on your individual, we thought it resembled, especially in the true eye arrangement, Araneus alboventris pictured on BugGuide and described on BugGuide as “Carapace, sternum, legs greenish yellow. Bright yellow rings around posterior median eyes.
Abdomen dorsum with black patch bordered by crimson red border on golden yellow background.” Then on BugGuide we found a male, recognizable because of the enlarged pedipalps, the first pair of appendages that are used to transfer sperm to the female.
A comment compares this individual to Araneus alboventris. We suspect this is a white spotted color variation of Araneus alboventris and we propose the common name Blind Eyed Orbweaver.
We love the many views you provided, including the lateral view that reveals the spinnerets.
I think I have a picture of this spider too. I saw it on my garden fence while I was mowing.
So this post prompts me to ask a question…
I think on Crowley’s Ridge in north east Arkansas we must have absolutely mutant Argiope Aurantia. Everything I’ve ever read on them indicates that the adult body size is only about 2 inches, and I see here that this little guy (legs and all) is only 2 inches.
Here’s my quandry… the average body size around here is about 3 inches in the rural areas closest to the city (unfortunately we have very few within city limits in Jonesboro, AR). But out on the ridge near the rice fields, holy CRAP!!! Their bodies and legs get as big as your face!
I’ve seen pictures friends have taken over the years of these ‘dinner plate’ spiders, but never seen them myself. I see the 3 inch ones all the time though, and they lay between 2-4 egg sacs each! I wouldn’t have believed they were from the same spider except I saw her in the process of spinning her 3rd the day after she spun #2.
This fall I will make a concerted effort to document some of these monsters, as I can’t find any technical information that these spiders reach more than 2 inches in body size. Anyone else ever seen these reach gargantuan size?
Dear all, I also spott a similar specimen in Bali, possibly Cyrtaachne inaequalis: http://www.projectnoah.org/spottings/583415317?utm_content=buffer683cc&utm_medium=social&utm_source=facebook.com&utm_campaign=buffer
I found one in illinois
This was really useful as I had run into this spider (its web!) on the Big Island in HI and couldn’t find someone who could tell me its name, species, etc. The ones I found on large orb webs outside the entrance of where I was staying are darker in color — more black — but otherwise exactly the same. As my sister commented, they look like Balinese masks. Thanks!
We have plenty of them in Maui. They leave an incredibly itchy bite. I have been bitten Many times landscaping my yard.
Far as I can tell, the name G. mammosa was synonomized with G. cancriformis, and this spider is still called that on a number of sites. However, it appears that that is incorrect, because this species has been separated and elevated to its own genus. The correct name, now used by the reputable scientific websites, is Thelacantha brevispina.
thanks for the correction on this ten year old posting.
I had a orange one about 1/2 inch in size and caught it and let it go in the woods in Palmer, Alaska
Found one at our new home on Oahu I couldn’t believe it was a spider because it stayed in the middle of its web curled up. I wish I could post a picture because the spines on this spider is cool