Tan Jumping Spider, Familiar Jumping Spider
Platycryptus undatus
Salticidae (Jumping Spiders), Order Araneae. Key family characteristics include large anterior median eyes and high visual acuity.
Physical Description
A flattened, fuzzy cephalothorax and abdomen. The body is relatively broad and compressed dorsoventrally, which allows it to hide in narrow crevices or under tree bark.
Size Estimate
Body length typically 8-13mm for females, males slightly smaller. Leg span approximately 15-20mm. The specimen in the photo appears to be an adult.
Coloration & Markings
Mottled gray, tan, and brown coloration. The abdomen features a distinctive central light-colored band with dark, wavy or 'undulating' edges (hence 'undatus'), flanked by darker chevrons.
Web Type
Does not build a hunting web. As a jumping spider, it produces silk for 'draglines' (safety tethers) and silken retreats for molting, sleeping, or guarding egg sacs.
Eye Arrangement
Not clearly visible in the photo, but characteristic of Salticidae: four eyes on the front face with two very large Anterior Median Eyes (AME), and four smaller eyes positioned on the sides and top of the head.
Leg Characteristics
Stocky, powerful legs used for jumping. They are covered in dense hairs (setae) and exhibit faint banding. The front legs are often slightly thicker for grasping prey.
Venom & Safety Information
Venom Information
Possesses venom used to paralyze insect prey. The venom is not considered medically significant to humans, acting more like a mild bee sting if a bite occurs.
Medical Significance
Low medical significance. Bites are extremely rare and usually only occur if the spider is pinched or crushed. Symptoms are typically limited to localized redness, itching, or minor swelling.
Safety Recommendations
Harmless to humans; no intervention is usually necessary. If removal from a home is desired, they can be easily caught in a cup and moved outside.
Habitat & Behavior
Habitat & Range
Common across North America, particularly in the Eastern United States and Canada. Often found on vertical surfaces like tree trunks, fence posts, and the exterior walls of buildings.
Behavior & Temperament
Active diurnal hunters with excellent vision. They are curious and generally non-aggressive toward humans. They track prey visually before performing a precise leap to capture it.
Diet & Prey
Generalist predators of small insects including flies, gnats, mosquitoes, and other small spiders. They use their vision to stalk prey and pounce from a distance.
Seasonal Activity
Most active from spring through autumn. Adults may overwinter in silken hibernacula tucked into crevices or behind loose tree bark.
Description
A charismatic and common jumping spider frequently encountered near human dwellings. Known for its 'fuzzy' appearance and distinctive wavy abdominal pattern, it is a master of camouflage on textured surfaces.
Key Features
Flattened body shape, mottled tan/gray coloration, and the dark 'wavy' pattern along the center of the abdomen.
Similar Species
May be confused with Menemerus bivittatus (Gray Wall Jumper) or members of the Marpissa genus, but the specific undulating abdominal pattern is diagnostic for P. undatus.
Life Cycle
Females lay eggs in a silken retreat, often under bark. They exhibit maternal care by guarding the sac until spiderlings emerge. Lifespan is typically 1-2 years.
Ecological Importance
Serves as an excellent natural pest control agent, consuming various nuisance insects around homes and gardens.
Conservation Status
Not evaluated by the IUCN, but considered common and stable throughout its native range.
Interesting Facts
They are known for their high intelligence among invertebrates and have been observed 'investigating' humans or camera lenses due to their keen eyesight.
Photography Tips
Focus on the 'face' to capture the large eyes. Use a macro lens or high-resolution setting. Frontal and top-down (dorsal) views are best for identification.
Identified: 2026-07-04T14:37:54.657004