Dome Web Spider: Essential Facts and Tips for Enthusiasts

folder_openArachnida, Araneae
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The Dome Web Spider, scientifically known as Mecynogea lemniscata, is a fascinating species known for its distinct web-building abilities. Their webs, whose structures resemble those of basilica buildings, give them their name basilica orbweaver spider. With a body about half an inch long, these spiders sport a brown color, but their abdomen features white wavy lines, narrow red bands, and black and yellow markings.

When it comes to the dome web spider’s habitat, they can often be found in gardens and other vegetative environments where their unique webs can be spotted among shrubs or small trees. These spiders are not notorious for being dangerous to humans; instead, they are primarily beneficial as they play a vital role in controlling insect populations.

Some characteristics of the Dome Web Spider include:

  • Unique dome-shaped web
  • Brown body with distinct markings
  • Half-inch body length
  • Found in gardens and vegetative environments

Dome Web Spider Overview

Arachnid Classification

Dome Web Spiders belong to the arachnid class, specifically the Araneae order. Arachnids are a class of joint-legged, invertebrate animals that also includes scorpions and ticks. The Araneae order is comprised of spiders, which are further grouped into families like Linyphiidae and Araneida. Araneomorphae, also known as true spiders, account for most of the spider diversity, including Dome Web Spiders.

Spiders vs Insects

Spiders and insects are both part of the arthropod phylum, but they have differences. Some distinctions include:

  • Number of legs: Spiders have 8, while insects have 6
  • Number of body segments: Spiders have 2, but insects have 3

Physical Characteristics

Dome Web Spiders are typically green with mottled brown markings. Key features include:

  • Small body size
  • Long legs

Distribution and Habitat

Dome Web Spiders can be found in various regions like Australia and India. They prefer woodlands and woodland edges. These spiders thrive in green, natural environments where they can blend in and find prey more easily.

Web and Hunting Strategies

Silk Bowl and Filmy Dome Structure

Dome web spiders create unique webs, known as silk bowls. These webs have a:

  • Filmy dome structure
  • Composed of several layers of silk

The silk bowl is positioned above a horizontal sheet called a horizontal trap.

Horizontal Trap

The horizontal trap:

  • Functions like an orb web or cobweb
  • Detects vibrations from caught prey
  • Helps spider locate and capture prey

Prey Capture

When it comes to prey capture, dome web spiders:

  • Rely on their webs to detect movements
  • Quickly move down the silk threads
  • Intricately wrap their prey in spider silk

To better understand the difference between dome web spiders and other spiders, take a look at this comparison table:

Feature Dome Web Spider Other Spiders
Web Silk bowl Orb web or cobweb
Structure Filmy dome with a horizontal trap No horizontal trap
Prey Detection Vibrations on horizontal trap Direct contact with a web or active hunting

Reproduction and Lifecycle

Mating Behavior

The mating process of the Dome Web Spider, also known as the Basilica Orbweaver Spider, begins with elaborate courtship rituals. The male approaches the female cautiously and then vibrates its abdomen to signal its intention. This behavior helps the male avoid being mistaken as prey by the female.

Egg Sacs

The female Dome Web Spider creates egg sacs after mating. These sacs serve as a protective enclosure for the eggs, which are placed inside. Here are some features of the egg sacs:

  • Made of silk
  • Typically positioned in a hidden or protected area
  • Can hold hundreds of eggs inside

Spiderlings

Upon hatching, the spiderlings emerge from their egg sacs as small and underdeveloped versions of their adult counterparts. These young spiders will undergo a series of molts as they grow, shedding their exoskeleton to accommodate their growing bodies.

Comparison of Female and Spiderlings:

Feature Female Spiderlings
Size Approximately half an inch long Significantly smaller, growing as they molt
Color/markings on abdomen White wavy lines with narrow red bands Similar markings, but less distinct
Role in reproduction Creates egg sacs and lays eggs inside Emerge from the egg sac and grow through molting

In summary, the Dome Web Spider’s reproduction and life cycle begins with a cautious mating ritual, followed by the female producing egg sacs to house her eggs. The spiderlings emerge from these egg sacs and develop through molting, eventually reaching adulthood with a distinct abdomen pattern.

Predators and Defense Mechanisms

Common Predators

Dome web spiders belong to the family Araneidae and, like other spiders, face a range of predators in the wild. Some common predators of Dome web spiders include:

  • Centipedes: Fast and venomous, centipedes can catch and overwhelm Dome web spiders.
  • Trapdoor spiders: These spiders are known for ambushing their prey, including other spiders such as the Dome web spider.
  • Birds: Various bird species feed on spiders, including those from the Araneidae family.

Venom

Although Dome web spiders possess venom, their bite is usually not harmful to humans. However, spider venom can have different effects on their prey. When it comes to venom potency and effects, there is a noticeable difference between Dome web spiders and some other spider species. A comparison table is provided below to demonstrate these differences:

Spider Species Venom Potency Effects on Humans
Dome Web Spider Low Mild pain, itching
Black Widow Spider High Severe pain, muscle cramps, nausea

As an arachnology enthusiast, it’s essential to understand the various venom characteristics and behavior of spiders. Dome web spiders, along with the entirety of the Araneidae family, have venom that serves primarily as a defense mechanism against predators and as a means to subdue and digest their prey.

Tips for Spider Identification

Physical Features

Identifying spiders is easier when looking at certain physical features. Some key features to observe are:

  • Color: Some spiders have specific colors, like the yellow garden spider with its bright yellow and black markings.
  • Carapace: Look at the pattern on the spider’s cephalothorax (head and thorax combined). For example, the brown recluse has a dark brown violin shape on its carapace.
  • Body length: Individual spiders might vary in body length, like the basilica orbweaver spider with a body about half an inch long.

Web Styles

Spiders also differ in their web styles, with some unique webs belonging to specific species:

Here’s a comparison table of some spider species with their unique features:

Spider Species Key Color Difference Unique Carapace Markings Body Length Web Style
Yellow Garden Spider Yellow and Black 1 – 2.8 cm Orb Web
Brown Recluse Dark Brown Violin Shape 0.6 – 1.9 cm Irregular Web
Basilica Orbweaver Mottled Brown Black and White Stripes ~1.3 cm Dome Web

Keep these tips in mind, and remember that venomous spiders can often be identified by their unique appearance. For example, the brown recluse is easily recognized by its violin-shaped marking and unique eye pattern. Meanwhile, woodland spiders like the fishing spider are usually shy and live in forested habitats.

Human Interaction and Spider Bite Treatment

Dome Web Spider Bites

The Dome Web Spider (Neriene radiata), also known as the Filmy Dome Spider, is a type of orb-weaver spider. Its bites are usually harmless to humans, causing mild irritation and discomfort.

First Aid Measures

In case of a bite from a Dome Web spider or a more venomous species like the Sydney Funnel Web Spider (Atrax or Hadronyche species), follow these first aid measures:

  • Clean: Wash the bite area with soap and water to reduce the risk of infection.
  • Cold compress: Apply an ice pack to reduce pain and swelling.

Compare Dome Web Spider with Sydney Funnel Web Spider:

Features Dome Web Spider Sydney Funnel Web Spider
Habitat Wood piles, brush Burrows
Risks to Humans Low, minimal harm High, potentially fatal
Bite Treatment Ice, OTC pain meds Antivenom, seek help

Places you are likely to find each spider species:

  • Dome Web Spider: wood piles and brush areas.
  • Sydney Funnel Web Spider: in burrows around Sydney, Australia.

Possible outcomes of a spider bite:

  • Dome Web Spider: Itching, mild pain.
  • Sydney Funnel Web Spider: Severe pain, muscle cramping.

Important first aid steps:

  • Clean the bite area.
  • Apply an ice pack to the bite site.

Pros and cons of Dome Web Spider bites:

  • Pros: Usually harmless, mild discomfort.
  • Cons: Painful, can cause skin irritation.

Remember to always exercise caution when interacting with spiders, even if they appear harmless. Be mindful of their habitats like wood piles, brush, and burrows, and watch out for spider-related structures like egg cases and webs.

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 – Dome Web Spider

 

Spider identity?
There were numerous webs similar to this one in a shed we have here in Wasilla, Alaska. The webs were all complete domes with a hole in the underside. The spiders were tiny brown, maybe 1/4 to 1/2" total body size. The spider resided in the very peak of the orb, upside down. After looking at the webs I think you’ll forgive our layman’s term for them (boobie spiders – VBG). The close ups show that the web has hundreds of support "wires" going off in all directions. I’ve never seen anything like this here in 39 years in Alaska. I also had a pure white what I would call a crab spider (because they are built like a dungeness crab, move sideways like one and have a very grumpy disposition) I will send along when I find it. I don’t know what they are either. Usually they are plain brown so the white one (especially "hiding" on a black pot) was a surprise. Great site! I am going to put a link to it on the website for our greenhouse. So many people (even me on occasion) kill a lot of bugs that turn out to be beneficial. I try to educate our customers on what is good and bad, but I still can’t identify some. Ladybird beetle larva send customers off in a tizzy until I explain what they are. We are very lucky here as we have few real pests, nothing poisonous or terribly harmful to people.
Thanks for a great site!
C. Herrin
Wasilla, Alaska

Hi C. Herrin,
We are trying to get a more conclusive answer on your spider species. Sadly, the spider is out of focus and only the web can be used for identification. We are leaning towards the Filmy Dome Spider, Neriene radiata. Eric Eaton wrote in: ” I would agree with the genus of dome spiders, Neriene. I don’ know if N. radiata reaches Alaska.”

Letter 2 – Sierra Dome Spider

 

Unusual web . . .
Hello from the redwoods!
I live in La Honda, which is in the redwoods south of San Francisco. My neighbor called me over this morning to take pictures of these amazing webs she found on the front of her trailer. The are dome-like and we haven’t seen this type of web before. Sorry about the quality of the pictures. I couldn’t get any closer without breaking the anchoring strands of the web. While I was taking pics a “gentleman caller” came to visit, but Miss ran him off by bobbing up and down in her dome. I did manage to get a shot before he was gone. Again, sorry for the quality. Anyway, can you identify this spider for us? Thank you,
Sharon Carthy

Hi Sharon,
The spider photo does not have enough detail to be certain, but indications are that this might be the Marbled Cellar Spider, Holocnemus pluchei, which is pictured on BugGuide. There is no mention of the distinctive web there, but other sites mention the dome web and one research paper by Elizabeth M. Jakob posted online indicates the species was introduced from the Mediterranean to California in the 1970s. We will contact Eric Eaton for verification. Eric provided this correction: “Hi, Daniel: Neat images! The spider is likely the “Sierra dome spider,” Neriene litigiosa. Something in the genus Neriene at any rate. They seem to be locally common where they occur. Keep up the great work! Eric”

Update(11/07/2007)
Found some info on Sierra dome spider here (as well as many other places, but this seemed the most “accessible” to me, the common lay-person): http://biology.unm.edu/biology /pwatson/public_html/pjw_cv.htm No pictures of the dome webs, though. I wonder if the SDS normally builds out in the open like these two did?
Sharon

Hi Sharon,
While there were no photos of the webs, there were photos of the spiders, and they do resemble the spider in your photo. Interesting that the article discusses the energy used during the elaborate mating ritual and that your original observations included the mating ritual.

Letter 3 – Dome Web Spider from Australia

 

Subject:  Melbourne spiders
Geographic location of the bug:  Backyard
Date: 11/25/2017
Time: 04:49 AM EDT
One black spider.
One big colorful  spider.
How you want your letter signed:  Email

Dome Web Spider

Your colorful spider is a harmless Orbweaver, and we believe we have correctly identified it as a Dome Web Spider or Tent Spider, Cyrtophora moluccensis, thanks to images posted to Brisbane Insects where it states:  “Tent Spiders build tent-shaped webs between plants and bushes. Their tent shaped webs are easily recognized, up to 60cm in diameter” and “Unlike the other spider webs, the webs of  Tent Spiders and Russian Tent Spiders do not have sticky silk. The spiders rest upside down in the middle of the tent from day to night. Sometimes we can see a few of the Tent Spiders build their tent webs joined together and cover an area of a few meters.”  We also found images on Deviant Art and Bush Pea.

Letter 4 – Filmy Dome Spiders Mating: Neriene radiata

 

Subject: Unknown spiders-Male/Female
Location: Southwest, MI, USA
October 18, 2013 4:45 pm
Had seen this black and yellow spider hanging out in my marigold patch. Thought it was an Orchard Orbweaver at first until I saw my photos on my computer. Then a few days later I saw another smaller spider along with the black and yellow striped one (it wasn’t moving) At first I thought the bigger one was dead and the smaller one was in the process of liquifying its dinner. Then I thought maybe this was a male and they were mating. The next day I checked on the same web and the two were still there and I took the second picture. I also took a video when I thought they might be copulating. It was most interesting. Every 20-30 seconds and amber fluid drop would appear between them and then disappear as if reabsorbed or eaten. Can you tell what these spiders are and what they were up to?
Signature: d. k. dodge

Unknown Spider
Female Filmy Dome Spider

Dear D.K. Dodge,
We don’t recognize your spiders, but based on the tangled web, we are guessing they might be Cobweb Spiders in the family Theridiidae.  We searched through BugGuide, and your spiders bear a slight resemblance to this pair of
Phylloneta pictipes, however that appears to be a more southern species.  Perhaps one of our readers will be able to assist in this identification.

Unknown Mating Spiders
Mating Filmy Dome Spiders

Dan,
Because of the link and the update, I googled Neriene radiata and it is definitely the Filmy Dome Spider in my photos. What is even more confirming is that person’s observation that the courtship lasted for days.  I remember being very surprised when I kept seeing the pair for several days straight as I had assumed that all spider mating was a fairly quick proposition. Thanks for being such a great resource.  More to come from this bug-loving naturalist….

Unknown Mating Spiders
Mating Filmy Dome Spiders

Hi D.K.,
Thanks so much for writing back to provide this identification update.  Your photos are stunning, and nearly identical to the image of mating Filmy Dome Spiders,
Neriene radiata, from BugGuide.

 

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: Dome Web Spider

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