Trapdoor Spider and Funnel Web Spider
APPEARANCE & IDENTIFICATION
Trapdoor and funnel web spiders both live in burrows and display some of the same types of behavior, so the two are often mistaken for one another.
Funnel web spiders appear dark brown or black in color and can be up to 1-1/2 inches.
Due to the fifty varying species of trapdoor spiders in the United States, there are some differences in the appearance of the respective species. Trapdoor spiders are similar in appearance to tarantulas, but trapdoor spiders are smaller since their bodies are between ⅓ to 1½ inch long (not including the length of their legs). Trapdoor spiders are brown and black, although some species are yellow-gray colored. A distinct characteristic of trap door spiders is their fangs, which have “rake-like” barbs that are used to move soil.
Funnel web spiders are nocturnal, which means they are active at night. The females create funnel-shaped webs, which are narrower at one end, and connect them to their burrow. The spider hides in the narrow end of the funnel, and when it feels a vibration from the web, it hurries to grab the invading prey.
Trapdoor spiders live in silk-lined underground burrows. Since they spend much of their time below ground, they are very secretive. On rare occasions, they can be seen after heavy rain or if the males roam indoors. Trapdoor spiders are not aggressive and are very unlikely to bite unless disturbed or handled. Even if a trapdoor spider should bite, their venom is very mild and the bite results in very little pain. Trapdoor spiders live anywhere between five and twenty years before they die.
Their hunting behavior is quite different than other groups of spiders. Rather than being active hunters, they wait for prey to come to them. They construct ground burrows surrounded by silk strands that function as “tripwires” to alert the spider of the prey’s presence. The spiders also construct a lid (trapdoor), which is hinged on one side with silk and covers the entrance to the ground burrow. When alerted by prey vibrating the tripwire strands, the trapdoor spider leaves the burrow and rushes out to capture the prey. Afterwards, the spider returns back inside the burrow and allows the trapdoor to close. It is important to note that not all species of trapdoor spiders build a lid that fits over its burrow entrance.
Many species of trapdoor spiders protect themselves from predators by holding down the burrow lid and making it hard for predators to get inside. Trapdoor spiders in the genus Cyclocosmia have developed an intriguing way of keeping predators out of their burrow. When alerted to the presence of a predator, this genus of trapdoor spiders rushes down into its burrow headfirst and pushes its hardened, rib-like tip of the abdomen into the burrow entrance, thus plugging the entrance.
Funnel web and trapdoor spiders feed on small insects and spiders that they capture in their burrows.
Funnel web spiders tend to inhabit moist environments, such as forests or wetlands. The preferred habitat of trapdoor spiders is soil located in areas of warmer environmental conditions.
REPRODUCTION & LIFECYCLE
Among both the trapdoor and funnel web spiders, the males will leave the burrow in search of mates, while the females rarely venture out, but stay behind to await prey. The females of both species also can lay hundreds of eggs at one time.
Trapdoor spider males leave their burrows in the summer months to set out to find a female mate. When a male finds a female’s burrow, he lets her know he’s interested by tapping on her burrow lid with his front legs. If she is receptive, they mate inside the burrow and afterwards the male leaves to go search for another female. A few months after mating, the female lays her eggs inside the burrow. When the eggs hatch, the small spiderlings stay inside the burrow where they continue to grow for up to several months. Before the spiderlings mature into adults, they will leave the burrow and make their own smaller versions of their mother’s burrow.
SIGNS OF THEIR PRESENCE
Funnel web and trapdoor spiders are very difficult to locate since vegetation and soil become natural camouflage for these spiders. Homeowners usually do not realize they have trapdoor spiders on their property.
PREVENTION & CONTROL TIPS
Control and preventive efforts are not practical or overly effective against these spiders. However, should a homeowner need to ask any questions or seek out advice for control of funnel web or trapdoor spiders, it is best to contact a pest management professional.