You may not be a fan of spiders but they do play a valuable role in the ecosystem: pest exterminator. Georgia’s mygalomorph spiders are divided into trapdoor and purseweb spiders. Here’s a quick look at both. Want more in-depth information about Georgia’s magnificent mygalomorphs? Check out this blog and this column by naturalist Dirk J. Stevenson.

 

Did you know?

  • Purseweb and trapdoor spiders belong to a group called “Mygalomorphs” which also includes tarantulas.
  • These spiders reach sexual maturity at 3 to 6 years and can live between 10 and 25 years
  • Female trapdoor spiders in the species Ummidia can be up to 2 inches long
  • There are potentially dozens of undescribed species in the U.S.
  • Trapdoor spiders in the U.S. don’t have strong venom and are docile
  • Mygalomorphs can produce silk but they cannot fashion webs.

 

Purseweb spiders

  1. Their spider senses tingle when it comes to food.

When its prey walks over the exposed part of the tube, the spider senses vibrations. It then attacks by impaling its prey with enormous fangs thrust through the tube wall. Once the prey is subdued, the spider cuts a slit in the tube and pulls the creature inside to eat when its ready. The attentive spider then stitches up the hole.

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Adult red-legged purseweb spider on its tube (Daniel D. Dye II)

 

  1. Spiders spend most of their lives in their tubular homes.

Purseweb spiders build tough silken tubes disguised with bits of lichen and moss. The tubes serve as shelter and hunting stations. The tubes extend up the sides of tree trunks but the bottoms end a few inches underground into damp soil. A recent survey found tubes up to a foot long built by mature female red-legged pursewebs.

 

  1. They’re surprisingly beautiful.

Sexually mature males are striking in color. Male red-legged pursewebs have tomato-red legs and a jet-black body. Blue pursewebs are metallic blue-black. This coloration likely wards off predators. Spider biologists consider them to mimic wasps.

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Male blue purseweb spider (Daniel D. Dye II)

 

  1. Affable arachnids.

Like all mygalomorphs, purseweb spiders are docile. Unless harassed, they have little interest in biting humans. They can be safely handled. Although when holding one, particularly a large female, try not to focus on the enormous fangs!

 

Trapdoor Spiders

  1. Their silk-lined burrows are built underground with a trapdoor at the surface.

For some species, the trapdoors to their burrows are impressive. Solid, cork-like, well-camouflaged and only about an inch wide. As described by researchers, “The burrow is only about 4-6 inches deep, and the spider depends on brute strength for protection. When disturbed, they insert their fangs into holes in the door and hold on to the sides with all eight legs.” For other species, the trapdoors are smaller, thinner and wafer-like. These species are tricksters and have side tunnels which are blocked with doors, that branch off the main stem.

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An adult female trapdoor spider at Griffin Ridge WMA (Dirk J. Stevenson)

 

  1. Georgia is also home to ravine trapdoor spiders. 

These compact, tank-like spiders are a favorite of arachnologists. It’s easy to understand why. Their bizarre, manhole cover-like abdomens are short and end in a hardened disc. The disc fits tight against the wall of their burrows and are serve as false trapdoors. This helps keep predators and flooding rains from their homes.

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Torreya trapdoor spiders fit their odd-ended abdomens against the walls of their burrows to protect against predators and rain. (Daniel D. Dye II)