Tan Jumping Spider, Familiar Jumping Spider
Platycryptus undatus
Salticidae (Jumping Spiders), Order Araneae. Characterized by high intelligence and excellent vision.
Physical Description
A stout, flattened jumping spider designed for camouflage on tree bark. It has a heavy-set cephalthorax and an elongated abdomen with a slightly fuzzy texture.
Size Estimate
Body length typically 10-13mm for females, males slightly smaller. Leg span approximately 20-30mm. This specimen appears to be an adult.
Coloration & Markings
Mottled grey, tan, and brown. The most diagnostic feature is the dark undulating (zig-zag/wavy) pattern down the center of the abdomen, outlined in a lighter cream or tan color.
Web Type
The Tan Jumping Spider does not build hunting webs. It creates silk 'retreats' or pupentacular sacs for molting, sleeping, and egg-laying in crevices.
Eye Arrangement
Four pairs of eyes in three rows. The anterior median eyes are significantly enlarged and forward-facing, providing high-resolution binocular vision and depth perception.
Leg Characteristics
The first pair of legs is often robust for grabbing prey. All legs have thick setae (hairs) and are banded with grey and tan tones to match the body.
Venom & Safety Information
Venom Information
Neurotoxic but specifically designed for small insects. It is very weak and not specialized for defense against mammals.
Medical Significance
Harmless to humans. Bites are extremely rare and typically only happen if the spider is being crushed. Symptoms are less severe than a bee sting, usually light swelling or redness.
Safety Recommendations
No specific safety precautions needed. If found indoors, they can be safely moved outside using a cup and a piece of paper, though they are beneficial houseguests.
Habitat & Behavior
Habitat & Range
Common across North America, especially the eastern United States. Frequently found on vertical surfaces including tree trunks, fences, and the exterior walls of houses.
Behavior & Temperament
Extremely curious and docile. An active diurnal hunter that uses its keen eyesight to stalk prey like a cat. They are known to 'investigate' humans by jumping onto cameras or hands.
Diet & Prey
Generalist carnivore feeding on small insects, flies, moths, and other spiders. They pounce on prey from a distance, using a silk dragline as a safety tether.
Seasonal Activity
Most active from late spring through autumn. They may overwinter as adults or sub-adults in silk-lined crevices.
Description
The Tan Jumping Spider is an charismatic, intelligent inhabitant of the suburban landscape. Its incredible camouflage makes it nearly invisible against bark, yet its curious nature often brings it into contact with people. Unlike many spiders that flee, this species will often watch its observer, tilting its head to gain a better view.
Key Features
Flattened body profile and the distinctive wavy/undulating dark pattern on the dorsal side of the abdomen.
Similar Species
Platycryptus californicus (found in the west) and various Menemerus species (Grey Wall Jumpers), which usually have different abdominal patterns.
Life Cycle
Females lay eggs in silk sacs hidden under bark or in siding. They often guard the sac until spiderlings emerge. They can live for 1 to 2 years.
Ecological Importance
Critical for natural pest control. They consume large quantities of flies and garden pests without the need for webs that clutter the environment.
Conservation Status
Not evaluated by IUCN, but considered common and stable throughout its range.
Interesting Facts
They have some of the best vision in the invertebrate world and can see in color, including UV light. They are often used in scientific studies of animal cognition.
Photography Tips
Focus on the face to capture the large 'puppy-dog' eyes. Using a macro lens and natural light will highlight the intricate patterns on their legs and abdomen.
Identified: 2026-07-19T18:43:33.510327