North Carolina’s diverse ecosystems, from coastal plains to the Appalachian Mountains, host many spider species. While many people might feel apprehension towards spiders, the vast majority are harmless to humans and play an important role in controlling insect populations. Understanding the different types of spiders found here can help alleviate concerns and highlight their natural contributions.
Venomous Spiders of Concern
Only a few spider species in North Carolina are medically significant due to their venom. The black widow spider is recognized by its glossy black body and a distinctive red or orange hourglass marking. Adult female black widows range from 0.5 to 1.5 inches in length. They construct irregular, messy webs in dark, undisturbed areas like woodpiles, sheds, under rocks, basements, and garages. Black widow spiders are not aggressive and bite only when threatened or accidentally pressed against skin.
The brown recluse is another spider of concern, though less common in North Carolina than elsewhere in the U.S. This spider is identified by its brown coloration and a dark, violin-shaped marking on its back, with the “violin” neck pointing towards the rear of its body. Unlike most spiders, brown recluses have six eyes arranged in three pairs, rather than eight. They are relatively small, typically measuring 0.25 to 0.5 inches in body length, with legs extending the total size. Brown recluse spiders prefer secluded, dark, and undisturbed locations like closets, attics, basements, and stored boxes.
Common Non-Venomous Spiders
North Carolina hosts numerous common, non-venomous spider species. Orb weavers create large, intricate, wheel-shaped webs, found in gardens, fields, and wooded areas. Species like the Black and Yellow Garden Spider (Argiope aurantia) are striking, with bright yellow and black patterns on their abdomens. Despite their sometimes large size and prominent webs, orb weavers are not dangerous to humans.
Wolf spiders are another common group, characterized by their robust, hairy bodies and active hunting behavior. Unlike many spiders, they do not build webs to catch prey; instead, they actively stalk and pounce on insects. These spiders vary in size, with some, like the Carolina wolf spider, reaching up to 3 inches in leg span, and are usually brown or gray. Wolf spiders are not aggressive, and their bites are painful but not medically significant.
Jumping spiders are small, compact spiders with excellent vision, distinguished by their large, forward-facing eyes. They are active hunters during the day, using their impressive jumping ability to catch prey on various surfaces like fences, plants, and inside homes. These spiders come in various colors and patterns and are harmless. Cellar spiders, often mistaken for “daddy long legs,” have very small bodies and exceptionally long, thin legs. They build loose, irregular webs in damp, dark places such as basements, crawl spaces, and corners of rooms, and are harmless.
North Carolina Spider Habitats
Spiders thrive in various habitats across North Carolina, adapting to different environmental conditions. Outdoors, they are found in gardens, wooded areas, and under rocks or logs, where they find ample prey and shelter. Many species inhabit areas near water sources, such as streams and ponds. Dense vegetation, leaf litter, and natural debris provide ideal conditions for many spider populations.
Spiders commonly inhabit indoor environments, seeking shelter, warmth, or prey. Basements, attics, closets, and garages provide dark, undisturbed spaces favored by species like black widows and brown recluses. Other common indoor spiders, such as cellar spiders, prefer damp, quiet corners, ceilings, and crevices. Spiders may enter homes through small cracks, gaps around windows and doors, or by hitchhiking on objects brought inside. Seasonal changes can influence their presence indoors, with some spiders seeking refuge from cold weather.
Key Identification Clues
Identifying spiders involves observing several characteristics, as precise identification often requires detailed examination. The type of web a spider constructs offers a clue; for example, orb weavers create symmetrical, circular webs, while black widows build irregular, messy webs. Body shape and size are important; spiders have two main body segments—a cephalothorax and an abdomen. The size and shape of the abdomen, along with the overall body length and leg span, help distinguish species.
Color patterns and markings provide further identification points. The red hourglass on a black widow or the violin shape on a brown recluse are distinct examples. Eye arrangement and number are definitive characteristics, though often difficult to observe; most spiders have eight eyes, but some, like the brown recluse, have six. Leg length, thickness, and hair or spine presence are also distinguishing features. While these clues assist in general identification, confirming a spider’s species often requires expert help.