Hourglass Trapdoor Spider: Quick Facts & Essential Info

folder_openArachnida, Araneae
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The Hourglass Trapdoor Spider is a fascinating creature, known for its intriguing behavior and unique appearance. This arachnid belongs to the family Ctenizidae and predominantly lives in silk-lined, underground burrows across the United States. One of the most striking features of this spider is its ability to construct well-camouflaged trapdoors that blend seamlessly with the surrounding environment.

Unlike other spiders, Hourglass Trapdoor Spiders spend most of their lives in these burrows, waiting patiently for prey to pass by. Their diet mainly consists of insects and small arthropods, and they use their powerful jaws to capture and crush their prey. With around 50 species in the Ummidia genus, these spiders exhibit a remarkable level of diversity in size, color, and behavior.

Their fascinating lifestyle and captivating appearance make the Hourglass Trapdoor Spider a truly intriguing subject. As you learn more about these unique creatures, you’ll discover their incredible adaptations and the role they play in the ecosystem. Stay tuned for all you need to know about the Hourglass Trapdoor Spider.

Understanding the Hourglass Trapdoor Spider

Scientific Classification

The Hourglass Trapdoor Spider belongs to the family Cyclocosmiinae, specifically the genus Cyclocosmia1. These spiders are related to other trapdoor spiders and are sometimes called Chinese Hourglass Spiders because they are native to China.

Physical Characteristics

Hourglass Trapdoor Spiders are known for their unique appearance. They have flat, round abdomens, often with an hourglass-shaped pattern.

  • Size: These spiders range between 0.5 to 1.5 inches in length2.
  • Colors: They display darker brown shades on their abdomen and lighter colors on their legs1.

Their physical adaptations help them survive, some of these include:

  • Trapdoor construction: Similar to other trapdoor spiders, they create silk-lined burrows with a trapdoor made of soil and silk for hunting and protection3.
  • Flat abdomens: Their abdomens have a hardened exoskeleton, which helps them quickly seal themselves in their burrows when threatened4.
Features Hourglass Trapdoor Spider Other Trapdoor Spiders
Size 0.5 – 1.5 inches Varies
Colors Dark brown & light colors Brown or black
Trapdoor Construction Yes Yes
Hiding Strategy Seals in burrow Stays in burrow

While Hourglass Trapdoor Spiders share characteristics with other trapdoor spiders, their unique flat and round abdomens set them apart.

Life Cycle & Reproduction

Males vs. Females

Hourglass trapdoor spiders exhibit some differences between males and females. Males tend to be smaller and more slender. Females are larger and more robust.

Comparison Table:

  Males Females
Size Smaller Larger
Body Shape Slender Robust

Eggs & Spiderlings

  • Females lay eggs in silk-lined burrows
  • Spiderlings hatch from eggs after a specific incubation period

Females produce egg sacs that are off-white in color. The sacs are typically hidden in dark, sheltered areas. Spiderlings emerge from the egg sacs after a certain period (for example, 24 to 36 days in some spider species).

Habitat & Distribution

Global Presence

The habitat of the hourglass trapdoor spider primarily spans across the southeastern United States. This spider genus is yet to be discovered in other regions such as China, Africa, Canada, or Southeast Asia.

Environmental Factors

Hourglass trapdoor spiders thrive in environments with ample vegetation. They reside in:

  • Silk-lined, underground burrows
  • Gardens and areas with dense plant cover

These spiders have a preference for:

  • Warm, humid conditions
  • Soil that’s easy to dig and maintain burrows in
Region Presence of Hourglass Trapdoor Spider Typical Habitat
United States Yes (southeastern states) Gardens, wooded areas, and areas with plant cover
China No N/A
Africa No N/A
Canada No N/A
Southeast Asia No N/A

Burrow & Trapdoor Construction

Burrow Structure

Hourglass trapdoor spiders are known for their unique burrows, which they construct in the soil. Some key features of their burrows include:

  • Lined with silk threads
  • Underground tunnels
  • Customized for each spider

The spiders use their silk in combination with soil to create a stable and comfortable living environment. The burrow structure typically consists of a single entrance, with the tunnel leading down to a small chamber where the spider resides.

Trapdoor Mechanism

Trapdoor spiders build a hidden door to conceal the entrance to their burrow. This door is cleverly constructed using:

  • Layers of silk
  • Soil and debris
  • Camouflage patterns

The trapdoor is attached to the burrow by silk threads, which also help the spider sense potential prey, as they vibrate when disturbed. Here is a comparison between hourglass trapdoor spiders and other trapdoor spiders:

Feature Hourglass Trapdoor Spider Other Trapdoor Spiders
Burrow Structure Silk-lined tunnels in soil Similar, but may vary by species
Trapdoor Material Silk, soil, debris Similar, but may vary by species
Camouflage Blends with surrounding environment May vary in effectiveness

Overall, the unique burrow and trapdoor construction of hourglass trapdoor spiders reflects their adaptation to their environment, allowing them to remain hidden while waiting for their prey.

Behavior & Diet

Prey and Hunting Techniques

The Hourglass Trapdoor Spider primarily preys on insects like grasshoppers, crickets, and flies. They have a unique hunting technique:

  • They live in silk-lined, underground burrows
  • They use a trapdoor to ambush their prey

The spider detects vibrations from insects walking nearby and quickly leaps out to capture them1.

Predators

Hourglass Trapdoor Spiders have several predators, including:

  • Birds
  • Rodents
  • Larger arachnids

These predators are usually attracted to the spiders due to their large size and the existence of their burrows2.

Comparison table of Prey and Hunting Techniques vs Predators:

Prey and Hunting Techniques Predators
Grasshoppers, crickets, flies Birds, rodents, larger arachnids
Underground burrows with trapdoors Attracted by large size and burrows

Venom & Defense

Venomous or Not?

The Hourglass Trapdoor Spider’s venom is not well documented, but typically, trapdoor spiders are not considered dangerous to humans. Though their bite could cause some discomfort, there is no need for alarm. Some similar non-dangerous spiders include:

  • Barn Funnel Weaver Spider
  • Jumping Spider

On the other hand, a dangerous venomous spider to be aware of is the Brown Widow Spider1.

Phragmosis & Severed Abdomen Spider

Phragmosis is a common defense mechanism employed by trapdoor spiders, including the Hourglass Trapdoor Spider2. It involves using their body, specifically the rigid disk on their abdomen, to block the entrance of the burrow. This tactic is effective against predators, like wasps and scorpions. Advantages of using phragmosis:

  • Prevents predator entry
  • Protects eggs and spiderlings in the burrow

One noteworthy phenomenon is the Severed Abdomen Spider, an occurrence where the spider’s abdomen is entirely severed from its body. They can survive this extreme form of self-defense, as their nervous system is not centralized and is distributed throughout their body3.

Conservation & Human Interaction

Importance in Ecosystem

Hourglass trapdoor spiders, like other arachnids, are part of the arthropod family and play a crucial role in their ecosystems. These subterranean hunters help regulate insect populations, serving as natural pest control. Additionally, they provide a food source for larger predators such as birds and reptiles.

Threats & Conservation Efforts

Unfortunately, these spiders face numerous threats, particularly habitat destruction due to human activities. Expansion of urban areas, deforestation, and agricultural practices can lead to the loss of their sandy burrows. Moreover, the presence of invasive species and climate change intensifies their risks.

To protect hourglass trapdoor spiders, it’s essential to emphasize conservation efforts. Some examples include:

  • Establishing protected areas for native habitats
  • Encouraging responsible land management practices, such as Habitat Conservation Plans

Here’s a quick comparison of the hourglass trapdoor spider with its distant relative, the tarantula:

Feature Hourglass Trapdoor Spider Tarantula
Habitat Subterranean, sandy burrows Various terrestrial habitats
Size Small to medium Generally larger
Burrow Construction Trapdoor, silk-lined Silk-lined, not always with trapdoor
Hunting Technique Ambush predator Ambush or active hunting

In summary, hourglass trapdoor spiders demonstrate the interconnected nature of arthropods in their ecosystems. By understanding their importance and addressing the threats they face, we can help conserve these unique creatures and maintain healthy ecological balance.

Footnotes

  1. Cyclocosmia 2 3 4
  2. Cyclocosmia ricketti 2 3
  3. Trapdoor Spiders 2
  4. Cyclocosmia trivia

 

 

 

 

 

 

Female California Trapdoor Spider

 

Almost as big as a dog: Female California Trapdoor Spider

 

 

 

 

 

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: Trapdoor Spiders

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13 Comments. Leave new

  • This spider looks incredible, look at the detail on it, amazing. It looks rather mean, I’m glad we don’t come across these in our home Curt – heh.

    Reply
  • These ugly spiders are now in Ketchikan, Alaska.

    Reply
    • We just found this spider in our garage tonight and we live in Ketchikan, too! Go back to Oregon, Folding Trapdoor Spider!!

      Reply
  • I just saw one of these on our house on Palomar Mtn. It has been raining most of the past 24 hours.

    Reply
  • Sabien wright-william
    October 26, 2017 1:58 am

    These guys are pretty docile! I’ve had no problems handling the males.
    They come into the house looking for… well, probably hormonal traces from a reticent household female, or a drink of water from our bathroom or kitchen.

    They are not at all aggressive with responsible handling. I guide them gently into my palm and put them outside.

    I don’t feel like I need a jar or anything when I hold these relatively slow, poorly-sighted and hardy arachnids. My first meeting with one, however, was a scream! It crawled onto my big toe while I was sitting on my couch. I’d never seen one before. I jumped up so fast, I actually saw it come down back onto the couch from how high up I kicked my foot.

    Then I took some pictures of him and took him outside.

    Reply
    • Thanks for letting us know of your humorous introduction to the Folding Door Spider. We are happy to learn you have grown to appreciate them.

      Reply
  • Sabien wright-william
    October 26, 2017 1:58 am

    These guys are pretty docile! I’ve had no problems handling the males.
    They come into the house looking for… well, probably hormonal traces from a reticent household female, or a drink of water from our bathroom or kitchen.

    They are not at all aggressive with responsible handling. I guide them gently into my palm and put them outside.

    I don’t feel like I need a jar or anything when I hold these relatively slow, poorly-sighted and hardy arachnids. My first meeting with one, however, was a scream! It crawled onto my big toe while I was sitting on my couch. I’d never seen one before. I jumped up so fast, I actually saw it come down back onto the couch from how high up I kicked my foot.

    Then I took some pictures of him and took him outside.

    Reply
  • Just saw this in my flower bed was about less then a foot from my foot I’m freaked out i ran back inside I didn’t kill it since I didn’t have shoes on ?? (Keizer, OR)

    Reply
  • Nathan Tamplen
    June 23, 2019 4:02 pm

    I think I just saw one in Silverton, OR killing a wasp. Not sure though.

    Reply
  • I have seen these on the underside of our home in Seattle Wa. There was about 4-5 when I sprayed around the base of the house when I moved here last year. They are VERY big and aggressive. I continue to monitor these spiders in the trees next to our house. They are extremely predatory and eat smaller spiders and insects directly. Most of the ones I saw were all black with minimal black fur around the abdomen and rear of the spider. Very big and fast. Actually remind me of big funnel web spiders because of the black color and stance.

    Reply
  • I think it’s Linothele uniformis, a new species, or close to it. They are funnel weavers.
    https://sciencepress.mnhn.fr/en/periodiques/zoosystema/43/10

    Reply
  • Just seen 2 trapdoor spiders in Ga. Didn’t know what it was till now. I sprayed it with a disinfect I had on me at work. It rolled over, played dead and tried to run but a friend layedvhis size 12 boots on it a killed it

    Reply

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