Antrodiaetidae

Antrodiaetidae: The Folding Trapdoor Spiders

Antrodiaetidae, commonly referred to as folding trapdoor spiders or folding-door spiders, represent a small but distinctive family within the spider order Mygalomorphae. These spiders are recognized for their close evolutionary relationship to tarantulas and for their unique burrow construction. Their common name directly describes a key characteristic: the specialized door they create to seal the entrance of their underground homes, which they can both fold and unfold.

Geographic Distribution and Habitat

The vast majority of Antrodiaetidae spiders are found within the United States, with their range predominantly covering the western and midwestern regions. Their presence extends from the Pacific coast of California northward to Washington, and they can also be found eastward into the Appalachian Mountains. Notably, two species, Antrodiaetus roretzi and Antrodiaetus yesoensis, are endemic to Japan. These Japanese populations are considered relict species, suggesting a much older and wider distribution for the family's ancestors, with their presence in Japan likely resulting from ancient vicariance events.

Biology and Behavior

Details regarding the specific biology and behavior of Antrodiaetidae, such as their diet, hunting strategies, and lifespan, are not extensively documented in the available information. However, their classification as trapdoor spiders implies a lifestyle centered around subterranean burrows. The defining feature of their behavior is the construction and operation of a hinged or folded door at the entrance of their burrow, which they use for protection and possibly to ambush prey. While venomous, as is characteristic of most spiders, the medical significance of their venom to humans is not specified. They are not generally considered web-building spiders in the typical sense, relying instead on their burrow and trapping mechanisms.