Spiders are a diverse group of arachnids with varied sizes, shapes, and color patterns. Many species exhibit distinctive markings, including white spots. However, white spots alone are not sufficient for precise identification, as these markings appear across various spider families. Accurate identification depends on observing a combination of characteristics.
Common Spiders with White Markings
Several common spider species have prominent white markings on their backs. The bold jumper (Phidippus audax) is a small, fuzzy spider, 0.25 to 0.75 inches in length. Its black body often features a distinct large white spot, sometimes triangular, in the center of its abdomen, accompanied by two smaller spots below it. Its chelicerae often display an iridescent metallic green or blue sheen.
The orchard orbweaver (Leucauge venusta) is another spider with noticeable white markings, measuring 0.13 to 0.3 inches. This species has a silvery-white abdomen with a dark stripe running down its center, often flanked by black, yellow, or red streaks. Its legs can be greenish.
Crab spiders, such as the goldenrod crab spider (Misumena vatia) or the whitebanded crab spider, often display white coloration. These spiders have a globular abdomen and can be white, yellow, or a combination of these colors, sometimes with spots or lines. They are known for their ability to change color to blend with their surroundings, often appearing uniformly white. Females reach up to 0.4 inches, while males are considerably smaller.
Additional Identification Clues
Accurately identifying a spider goes beyond just its color patterns. The overall body shape and size offer significant clues; spiders can be robust, elongated, or flattened, with body lengths varying widely. Examining the spider’s legs provides further detail, as their thickness, length relative to the body, and presence of distinct patterns or hairs can be unique to certain species.
The arrangement of a spider’s eyes is a distinguishing feature. Most spiders possess eight eyes, but their size and positioning on the cephalothorax vary among families. Some spiders have large, forward-facing eyes, while others have eyes arranged in two rows or other patterns. The type of web a spider constructs, if any, also aids identification. Common web types include circular orb webs, irregular tangle webs (cobwebs), sheet webs, or funnel webs. Many spiders, like jumping spiders, do not build webs to catch prey but actively hunt, exhibiting movements like leaping or scurrying sideways.
Where These Spiders Live
Spiders with white markings can be found in various environments depending on their adaptations and hunting strategies. Outdoor habitats include gardens, fields, and forests, where spiders may reside among plants, under rocks, or beneath logs. Some species prefer moist, wooded areas, which offer both shelter and a consistent food supply of insects.
Spiders also inhabit indoor spaces, often seeking dark, secluded areas like basements, attics, or room corners. These indoor dwellers may enter homes through small openings around doors or windows. Geographically, many spiders with white markings are widespread across temperate zones, found throughout much of North America, and some species have been introduced to other parts of the world.
Understanding Venom and Risk
While most spiders possess venom, the majority are not medically significant to humans. Many species have fangs too small or weak to puncture human skin, or their venom is not potent enough to cause more than a minor, localized reaction. A bite from a common spider might result in symptoms similar to a bee sting, such as redness, mild pain, and swelling at the bite site.
If bitten, clean the affected area with mild soap and water. Applying a cool cloth or ice pack can help reduce pain and swelling, and elevating the bitten limb may also be beneficial. Over-the-counter pain relievers or antihistamines can alleviate discomfort and itching. Seek medical attention if symptoms worsen, spread, or include severe pain, muscle cramping, or difficulty breathing. The few spider species considered medically significant, such as the brown recluse or black widow, do not feature prominent white spots on their backs.