Spider identification is not an easy task, and most commonly, the best novices can hope for is identification to family level. The combination of ground color and markings are not enough to identify most spiders positively, and many spiders are black with white markings, a few common species sometimes display such markings. Jumping spiders are common and many species are black and white; however, orb weavers and garden spiders are sometimes very dark with white spots as well.
Identifying spiders is a difficult task; obvious characteristics, such as base color and markings, are variable and subjective. When experts try to distinguish among the more than 44,000 living species, they must use technical characters such as eye number and position and the arrangement of spinnerets. Using such criteria is usually beyond the skill and interest level of the casual observer, and identification to family level is usually sufficient.
Jumping spiders form a large family called the Salticidae; in total, the group contains about 5,600 species worldwide. Ubiquitous and commonly encountered, jumping spiders are small, active predators of insects and other invertebrates. Though usually tiny, jumping spiders are stout arachnids, with hair-covered bodies. The daring jumping spider (Phidippus audax) is a particularly common species in North America. Most have a black ground color with various combinations of white spots, bars and bands on their cephalothorax and abdomen; some have white markings on the legs as well. Daring jumping spiders typically have between one and four white markings on their abdomen.
Orb Weaving Spiders
Approximately 3,000 species known as orb weaving spiders inhabit the planet. Known for their large, showy webs they use to capture flying insects, people frequently encounter these spiders in gardens, forests and suburban areas. Some species -- particularly black and gold argiopes (Argiope aurantia) – display bold black and gold colors, occasionally with white spots on their abdomens. Living near water, Larinioides sclopetarius is another black and white orb weaving species -- sometimes their markings may appear like two white dots. Asian spiny-backed spiders (Gasteracantha mammosa) often have red abdominal margins and two white spots atop a black ground color. Though venomous, most orb weaving spiders are harmless to humans.
Most wolf spiders are clad in a single color, or – among those species with markings – they have tiger-like markings. However, in some cases, light-colored markings on their abdomen may resemble white spots. Wolf spiders are active hunters, that prowl in the grass, leaf litter and on trees for their prey. You may observe female wolf spiders dragging large egg sacs from their abdomens.
- Missouri Department of Conservation: Black-and-Yellow Garden Spider
- Portland State University: Spiders Commonly Found in Gardens and Yards
- University of Michigan: Orbweavers
- Little Creatures that Rule the Earth: Araneidae
- University of Michigan: Jumping Spiders
- Fairfax County Public Schools: Daring Jumping Spiders
- American Museum of Natural History: The World Spider Catalog, Version 14.0
- University of Nebraska-Lincoln: Wolf Spiders in Nebraska