Tan Jumping Spider
Platycryptus undatus (likely)
Salticidae (Jumping Spiders), Order Araneae. Key family characteristics include exceptionally large anterior median eyes, acute vision, active day-hunting behavior, and compact, robust bodies.
Physical Description
A medium-sized jumping spider with a flattened, compact body covered in short, dense setae giving it a fuzzy appearance. The cephalothorax is dark with a reddish-brown face band, while the broad, oval abdomen exhibits a classic wavy pattern.
Size Estimate
Body length is typically 8-13 mm for adult females and 8-10 mm for adult males, with a total leg span of around 15-20 mm.
Coloration & Markings
Characterized by a mottled tan, grey, and white coloration designed for camouflage against tree bark. The abdomen features a central light-colored, dark-bordered wavy longitudinal band (undulating pattern).
Web Type
Does not build web traps to capture prey. Instead, it constructs small, tubular silk shelters or retreats under loose bark, in crevices, or in window tracks for resting, molting, and egg-laying.
Eye Arrangement
8 eyes total in three rows. Two extremely large Anterior Median Eyes (AME) dominate the front of the face, providing high-resolution binocular vision, flanked by smaller Anterior Lateral Eyes (ALE) and smaller Posterior Median/Lateral eyes along the carapace.
Leg Characteristics
Short, thick, strong legs specialized for jumping rather than speed running. Usually grey to light brown with subtle dark banding and dense hair coverings.
Venom & Safety Information
Venom Information
Contains mild, harmless venom optimized for paralyzing small insect prey. Venom is not medically toxic to humans or domestic pets.
Medical Significance
Not medically significant. Bites are extremely rare and usually only occur if pressed firmly against the skin. Symptoms are minor, typically causing slight localized redness or mild discomfort comparable to a minor gnat bite.
Safety Recommendations
Harmless and beneficial to keep around gardens and human dwellings. If found indoors, gently relocate it outside using the cup-and-paper method.
Habitat & Behavior
Habitat & Range
Widely distributed across eastern North America, from southern Canada to Florida and west to Texas. Frequently found on vertical wooden surfaces such as tree trunks, fences, wooden decks, and exterior walls of houses.
Behavior & Temperament
Curious, highly active diurnal hunter. Extremely dociles towards humans and rarely bites. When approached, it often turns to face the observer, tracking movement with its large eyes.
Diet & Prey
Feeds on a wide variety of small invertebrates including flies, mosquitoes, moths, leafhoppers, and smaller spiders. Secures prey by stalking closely and pouncing with a silk safety dragline attached.
Seasonal Activity
Most active from late spring through early autumn. Adults often overwinter in protected silken retreats under bark or structural siding.
Description
The Tan Jumping Spider is a charming and common resident of woodlands and suburban gardens in eastern North America. Renowned for its superb camouflage against tree bark and its remarkably alert, curious demeanor, this harmless visual predator is a favorite among arachnid enthusiasts.
Key Features
Distinguished by its flattened body shape, grey-tan mottled coloration, distinctive wavy central stripe on the dorsal abdomen, and classic jumping spider face with enlarged front eyes.
Similar Species
Platycryptus californicus (western relative), Marpissa muscosa (European equivalent), and various species of Metacyrba or Menemerus (Grey Wall Jumper). Distinguished by the specific wavy abdominal pattern.
Life Cycle
Females construct silk egg sacs in protected crevices during spring or early summer, guarding them until spiderlings emerge. Spiderlings disperse via ballooning or crawling and mature through several molts over 1-2 years.
Ecological Importance
Serves as an essential natural pest controller in gardens and forests, regulating populations of flies, agricultural pests, and soft-bodied insects.
Conservation Status
Not evaluated by the IUCN, but widely abundant and stable throughout its native range with no significant conservation threats.
Interesting Facts
Despite their small size, jumping spiders have some of the best vision among invertebrates, capable of perceiving color and depth perception. They use a hydraulic propulsion system in their legs to leap many times their body length.
Photography Tips
Get down to eye level to capture its expressive front eyes and reddish face markings. Use macro equipment and high shutter speeds to handle quick jumping movements.
Identified: 2026-07-26T15:40:00.976372