Tennessee is home to a diverse array of spider species, most of which are harmless and play an important role in controlling insect populations. These arachnids can be found in various habitats, from dense forests to urban backyards and inside homes. Understanding the types of spiders present helps in appreciating their natural behavior and recognizing that many are not a threat to humans.
Common Spiders Across Tennessee
Many common spiders construct intricate webs to capture prey. Orb weaver spiders, such as the garden spider (Argiope aurantia), build large, circular webs in gardens, fields, and between structures. These spiders have stout bodies, often brightly colored with distinct patterns on their abdomens. Funnel weavers, often called grass spiders (Agelenopsis species), create sheet-like webs with a funnel-shaped retreat where they wait for insects. Their webs are commonly seen on lawns, shrubs, and low vegetation, especially when covered in dew.
Wolf spiders (family Lycosidae) are active hunters that do not build webs for prey capture. These robust, hairy spiders are often found on the ground in grassy areas, leaf litter, or under rocks and logs. They are known for their excellent eyesight and rapid movements as they pursue insects. Jumping spiders (family Salticidae) are also active hunters, recognized by their large, forward-facing eyes and jerky movements. These small, often colorful spiders are frequently seen on walls, fences, and plants, using keen vision to stalk and pounce on prey.
Cellar spiders (Pholcidae family), commonly known as “daddy long-legs,” are often found in damp, dark areas like basements, crawl spaces, or corners of rooms. These spiders have very long, thin legs and small bodies, building loose, irregular webs. Despite their appearance, they are harmless to humans. The American house spider (Parasteatoda tepidariorum) builds messy, irregular webs in corners of homes and other structures.
Spiders Requiring Caution in Tennessee
While most spiders in Tennessee are not dangerous, two species warrant caution due to their venom: the brown recluse spider and the black widow spider. These spiders are not aggressive and typically only bite when they feel threatened or accidentally pressed against skin. Understanding their characteristics and habitats can help residents avoid unintentional encounters.
The brown recluse spider (Loxosceles reclusa) is native to Tennessee and is recognized by a violin-shaped marking on its cephalothorax. This marking points towards the abdomen, though its clarity can vary among individuals. The spider’s color ranges from light tan to dark brown, measuring about 0.24 to 0.79 inches (6 to 20 mm) in body length. Brown recluses prefer secluded, undisturbed areas such as closets, attics, basements, and sheds, often hiding under furniture, boxes, or debris. They are most active during warmer months, from approximately March to October.
Both southern (Latrodectus mactans) and northern (Latrodectus variolus) black widow spiders are found in Tennessee. Female black widows are glossy black with a distinct red hourglass marking on the underside of their abdomen. The southern black widow usually has a complete hourglass, while the northern black widow may have a broken or separated marking. They measure about 0.5 inches (1.27 cm) in body length, with males being smaller and lighter. Black widow spiders construct irregular, strong, tangled webs in dark, sheltered locations, including woodpiles, sheds, garages, and under outdoor furniture.
Identifying Tennessee Spiders
Accurate identification of spider species in Tennessee involves observing physical features and web characteristics. Focusing on these comparative traits helps in accurate identification, aiding in understanding harmless versus cautious species.
Distinguishing a brown recluse from other brown spiders is a common identification challenge. The brown recluse has six eyes arranged in three pairs, a unique feature compared to the eight eyes most other spiders possess. While the violin marking is a helpful indicator, its clarity can vary, and some other spiders may have similar patterns.
Wolf spiders are often confused with brown recluses due to their brown coloration. However, wolf spiders are typically much hairier, have more robust bodies, and possess eight eyes, often with two very prominent ones. They also lack the distinct violin marking. Brown recluse legs are uniformly colored without stripes or bands, unlike many wolf spiders.
Web structure provides a clue for identification. Black widow spiders create strong, irregular, three-dimensional webs often described as “tangled.” These webs are not neatly organized like classic orb webs. Orb weavers construct large, symmetrical, circular webs with spokes radiating from a central hub. This web type indicates an orb weaver, not a spider of caution.
Spider behavior also offers insights. Jumping spiders actively stalk and pounce on their prey during the day, using their excellent vision. They do not build webs to catch food but may create small silken retreats. In contrast, cellar spiders hang upside down in their loose, irregular webs. Learning these features enhances identification.
Common Spiders Across Tennessee
These common spiders are often identified by their typical locations and behaviors. Orb weavers are frequently seen hanging head-down in their large, circular webs in gardens and fields. Wolf spiders, often mistaken for other species due to their brown and gray coloration, are robust hunters found on the ground in grassy areas or under rocks.
Jumping spiders are small, agile predators often encountered on vertical surfaces like walls and fences. Funnel weavers’ sheet-like webs are commonly seen on lawns and shrubs, especially when covered in morning dew. Cellar spiders, or “daddy long-legs,” build loose, irregular webs in damp, dark areas like basements. The common house spider is known for its messy, irregular webs in home corners.
Spiders Requiring Caution in Tennessee
To minimize encounters, residents should be aware of their preferred hiding spots. Brown recluse spiders favor secluded, undisturbed areas such as closets, attics, basements, and sheds, often hiding under stored items or debris. They are most active during warmer months. Black widow spiders construct strong, irregular, tangled webs in dark, sheltered locations, including woodpiles, sheds, garages, and crawl spaces. Recognizing the brown recluse’s violin marking and the female black widow’s red hourglass is key for identification and caution.
Identifying Tennessee Spiders
Accurate spider identification often comes down to a few key distinctions. For brown recluses, focus on the six-eye arrangement and the absence of leg banding, as the violin marking can vary. Remember that many harmless brown spiders, like wolf spiders, are larger, hairier, and have eight eyes.
For black widows, the glossy black body and red hourglass are primary indicators, along with their messy, irregular web structure. In contrast, orb weavers create highly organized, circular webs. Observing a spider’s behavior, such as active hunting versus web-dwelling, also provides valuable clues.
Tennessee’s ecosystems support many harmless spider species that play an important ecological role. They contribute to natural pest control, helping maintain balance in outdoor and indoor environments. Understanding their characteristics and behaviors can help alleviate undue concern.