Grey House Spider, Australian House Spider
Badumna longinqua
Desidae (Intertidal and House Spiders), Order Araneae
Physical Description
Robust, stout-bodied spider with a dark, glossy cephalothorax and a dense, velvety grey to dark brown abdomen. Females are generally larger and more robust than males.
Size Estimate
Body length ranges from 9 to 18 mm for females, with a leg span of approximately 30 to 45 mm. This specimen appears to be an adult.
Coloration & Markings
Dark brown to nearly black cephalothorax with lighter grey or mottled markings on the dorsal abdomen, sometimes featuring a faint longitudinal pattern or chevron-like markings.
Web Type
Lace-web or cribellate retreat web, forming a characteristic messy sheet with a tubular retreat where the spider hides, frequently built in window corners, crevices, and bark.
Eye Arrangement
Eight eyes arranged in two rows of four, relatively uniform in size, typical of cribellate spiders with a compact central eye group.
Leg Characteristics
Moderately long, robust, and covered in fine setae. Legs often feature subtle banding and are held in a spread posture typical of web-dwelling cribellate spiders.
Venom & Safety Information
Venom Information
Possesses mild neurotoxic venom used to subdue invertebrate prey. Not considered medically significant to humans.
Medical Significance
Harmless to humans. Bites are rare and typically occur only when the spider is trapped against the skin. Symptoms are usually minor, localized pain, swelling, and redness that resolve quickly.
Safety Recommendations
Avoid direct handling without protection. If found inside, it can be safely relocated outdoors using a container and a piece of card.
Habitat & Behavior
Habitat & Range
Native to Australia and New Zealand, but introduced globally to parts of North America, Europe, and South Africa. Commonly found on building exteriors, fences, bark, and window frames.
Behavior & Temperament
Nocturnal ambush predator that remains hidden in its tubular retreat until prey triggers the cribellate silk web. Generally timid and reluctant to bite unless severely provoked.
Diet & Prey
Primarily feeds on flying insects such as flies, moths, beetles, and mosquitoes that become trapped in the sticky, woolly cribellate silk.
Seasonal Activity
Most active during the warmer spring and summer months, when males actively wander in search of females for mating.
Description
The Grey House Spider is a familiar commensal species often encountered around human habitations. With its velvety appearance and distinctive messy lace-web, it serves as an efficient natural pest controller in gardens and around homes.
Key Features
Glossy dark cephalothorax, velvety grey patterned abdomen, and characteristic messy sheet web with a distinct tubular retreat.
Similar Species
Badumna insularis (Black House Spider), which is generally darker, larger, and prefers similar urban microhabitats.
Life Cycle
Females construct silken egg sacs hidden near the web retreat, depositing dozens of eggs. Spiderlings disperse via ballooning after hatching. Lifespan typically ranges from one to two years.
Ecological Importance
Acts as an effective predator of flying pest insects around human structures, helping to regulate populations of mosquitoes, flies, and moths.
Conservation Status
Not evaluated by the IUCN, but highly adaptable and abundant throughout its native and introduced ranges.
Interesting Facts
Despite being native to Australasia, Badumna longinqua has successfully hitchhiked via international commerce to establish stable populations worldwide.
Photography Tips
Photograph from above or a slight side angle to capture abdominal patterns and leg structure. Use macro lighting carefully to highlight the velvety texture without startling the spider.
Identified: 2026-08-16T09:13:54.203868