Grey House Spider, Domestic House Spider, Wharf Spider
Badumna longinqua
Desidae (Intertidal and House Spiders), Order Araneae
Physical Description
Robust, stout body with a dark greyish-brown cephalothorax and a patterned, velvety abdomen. The carapace is typically darker and smoother, while the abdomen features a mottled or chevron-like pattern. Females are generally larger and heavier-bodied than males.
Size Estimate
Body length ranges from 9 to 18 mm for females and 6 to 12 mm for males, with a leg span of approximately 25 to 35 mm. The specimen pictured appears to be a robust adult or late-stage sub-adult.
Coloration & Markings
Dark grey to charcoal base color with lighter yellowish-grey or whitish mottling on the dorsal abdomen, often forming a faint, scalloped or banded pattern. Legs are uniformly dark grey, sometimes with indistinct banding.
Web Type
Messy, characteristic sheet or funnel-like web built in corners, window frames, and crevices. The web features a retreat tube where the spider hides, leading out to a non-sticky, lace-like cribellate sheet of silk.
Eye Arrangement
Eight eyes arranged in two slightly curved rows across the front of the carapace, typical of cribellate spiders. The eyes are relatively small and equal in size, spread evenly across the head region.
Leg Characteristics
Robust, moderately long legs covered in fine setae. The legs are sturdy and adapted for rapid movement across their sheet webs, with no extreme elongation or specialized spination visible.
Venom & Safety Information
Venom Information
Possesses mild neurotoxic venom used primarily to subdue invertebrate prey. It is not considered dangerous to humans, though bites can cause localized pain and swelling.
Medical Significance
Low medical significance. Bites from Badumna longinqua are uncommon due to their shy nature. Symptoms of a bite typically include minor local pain, swelling, and redness, rarely resulting in systemic effects unless an allergic reaction occurs.
Safety Recommendations
Avoid direct handling to prevent accidental bites. If found indoors, they can be safely relocated outside using a container and a piece of card. Standard cleaning will deter web formation.
Habitat & Behavior
Habitat & Range
Native to Australia and New Zealand, but introduced globally to parts of North America, South America, Europe, and South Africa. Commonly found in urban environments, around buildings, under bark, on tree trunks, and in window frames.
Behavior & Temperament
Nocturnal ambush hunters that spend most of their time waiting inside their silk retreat tubes. They are generally timid and will retreat rapidly when disturbed, though females guarding egg sacs may show defensive posturing.
Diet & Prey
Predominantly feeds on flying and crawling insects that become entangled in the non-sticky cribellate silk, including flies, moths, beetles, mosquitoes, and ants.
Seasonal Activity
Active year-round in temperate indoor environments, with peak foraging and mating activity occurring during the warmer spring and summer months.
Description
The Grey House Spider is a familiar yet unobtrusive urban dweller known for its messy corner webs and secretive habits. With its velvety dark body and robust build, it plays a valuable role in keeping household insect populations in check while rarely interacting with humans.
Key Features
Robust dark grey body, velvety mottled abdomen, characteristic messy funnel-like retreat web found in corners or window frames, and cribellate silk structure.
Similar Species
Badumna insignis (Black House Spider), which is typically darker black and prefers similar urban habitats; can be distinguished by its deeper coloration and slightly different geographic preferences.
Life Cycle
Females construct tough, disc-shaped white egg sacs within or near their retreat webs, containing dozens of eggs. Spiderlings disperse via ballooning after hatching. They undergo multiple molts over a 1 to 2 year lifespan.
Ecological Importance
Acts as an effective natural pest controller in residential and natural environments, helping regulate populations of flies, mosquitoes, and other nuisance insects.
Conservation Status
Not evaluated by the IUCN, but populations are widespread, highly adaptable, and thriving globally, particularly in human-modified landscapes.
Interesting Facts
Despite being native to Australasia, Badumna longinqua has successfully hitchhiked via international trade to become a well-established urban resident in coastal regions worldwide.
Photography Tips
Photograph from a safe lateral or top-down angle using natural indirect lighting or a diffused macro flash to highlight the abdominal patterns and structural details of the carapace.
Identified: 2026-09-06T06:29:37.397696