Adanson's House Jumper
Hasarius adansoni
Salticidae (Jumping Spiders), Order Araneae
Physical Description
Compact, robust body with a somewhat flat cephalothorax and an oval-shaped abdomen. The body is covered in fine hairs (setae). Males typically have longer front legs and more striking markings than females.
Size Estimate
Body length is typically 6-8mm for males and 8-10mm for females. Leg span is roughly 15-20mm. This specimen appears to be an adult male.
Coloration & Markings
Black to dark brown base color. Males exhibit a distinctive white crescent-shaped band on the back of the cephalothorax and two white dots on the rear of the abdomen. The pedipalps are often covered in white hairs, resembling a white 'mustache'.
Web Type
None. This is a cursorial hunting spider. They do not spin webs to catch prey but build small silk 'pup-tents' or retreats for molting, sleeping, and egg protection.
Eye Arrangement
Four pairs of eyes with a very large pair of Anterior Median Eyes (AME) providing high-resolution stereoscopic vision. The smaller eyes are arranged in a rectangular fashion on the cephalothorax for motion detection.
Leg Characteristics
The first pair of legs in males is heavily built, darker, and often held forward in an assertive posture. They are equipped with scopulae (adhesive hairs) for climbing smooth surfaces like glass.
Venom & Safety Information
Venom Information
Neurotoxic venom specialized for paralyzing small insects. It is of very low potency relative to human physiology and is not considered medically significant.
Medical Significance
Harmless. Bites are extremely rare and usually occur only if the spider is pinched against the skin. Symptoms are typically milder than a bee sting, involving localized redness or slight itching.
Safety Recommendations
No action needed. If desired, they can be safely relocated using a cup and card. They are beneficial roommates that do not create messy webs.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution; found globally in warm climates. Heavily associated with human dwellings (synanthropic), frequently seen on walls, ceilings, and in gardens.
Behavior & Temperament
Active diurnal hunter with feline-like movement. They exhibit curious behavior, often tracking movement (including cameras) with their large eyes. They are non-aggressive toward humans and prefer to jump away when threatened.
Diet & Prey
Generalist predators targeting small insects like flies, gnats, mosquitoes, and silverfish. They hunt by stalking and pouncing with high precision, using a silk tether for safety.
Seasonal Activity
Active year-round in indoor environments or tropical climates; peak activity in late spring and summer in temperate regions.
Description
Adanson's House Jumper is one of the most successful urban-adapted spiders in the world. Often referred to as the 'cat' of the spider world, it uses its incredible vision to stalk prey across domestic walls. Its charismatic 'mustache' and curious nature make it a favorite among arachnologists.
Key Features
Male's white crescent band on cephalothorax, white pedipalps ('mustache'), large forward-facing eyes, and dark, robust first legs.
Similar Species
Menemerus bivittatus (Gray Wall Jumper) which is flatter and grayer, and various Phidippus species which are typically much larger and more hirsute.
Life Cycle
Females lay eggs in silk-lined retreats. Spiderlings emerge and often disperse via ballooning. Adult lifespan is approximately 1-2 years.
Ecological Importance
Critical domestic pest control; they act as a natural, non-toxic buffer against flies and other indoor pests.
Conservation Status
Not evaluated by IUCN; however, populations are stable or increasing due to urban expansion.
Interesting Facts
The male's white pedipalps are used in elaborate signals during courtship to prevent the female from attacking him. They are also among the few spiders capable of seeing and reacting to their own reflection in a mirror.
Photography Tips
Focus on the eyes to capture the 'soul' of the spider. High shutter speeds are needed as they move in quick, jerky bursts. Side-profile shots highlight the white markings.
Identified: 2026-07-08T18:04:26.285550