Badumna longinqua

Badumna longinqua is an average-sized spider, with males attaining a maximum length of no more than 11 millimetres (0.43 in), while females are marginally larger with a maximum body length of 15 mm (0.59 in).[2][3] Its common name, grey house spider, is due to colouration on the cephalothorax and abdomen, which are carpeted with light-grey hairs and spot-like markings[4][5][6] and legs, which are purplish-brown in colour with hairs arranged into stripes on each leg.[7] The similarly coloured brown carapace darkens nearer the chelicerae and eyes.[7] Its eight eyes are small and black, with the front middle pair exceptionally larger at approximately 1 and a half times the size of surrounding eyes.[5][8] Underneath these setae is an ovate abdomen and legs, which are purplish-brown in colour with hairs arranged into stripes on each leg.[9]

The female Badumna longinqua spider can potentially spend the whole of her life in the one same web,[3][14] whereas the sexually mature male is forced to leave his home when it becomes time to reproduce.[8] The male begins his hunt for females in the warmer months of the year, from summer through to early autumn.[7][8] Although the details of B. longinqua courtship have not yet been formally described, and biology of the spider is not well studied, it is acknowledged in most cases to be a solitary spider.[7][16] The lifespan of Badumna longinqua is not officially documented, however its closest relative Badumna insignis lives for a maximum of around two years, and so it could be postulated that B. longinqua would live for approximately the same period of time.[17]

As a starting point for its web, Badumna longinqua first finds a satisfactory hiding place, such as a crack or small opening to funnel out its web from, which it then interlines with silk.[11][3][12][8] From this tubular entrance, it builds a multitude of ladder-like webs in a radiating fashion,[10][18][19] and for this reason it is placed into the ladderweb spiders grouping, of which it is one of only a few in New Zealand.[7] The grey house spider's special cribellate silk is used for the connecting zig-zag patterned threads of the web.[12][13][6] Located in the spider's rear legs, the calamistrum combs the silk of the web.[8] As the web is occupied for long periods of time,[11][4][12][2][3] with the female spider even remaining in her web for the entirety of her life unless compelled to move[3][14] silken additions and restorations are carried out nightly, resulting in a disorderly looking web which becomes increasingly untidy over time.[11][4][12][2][3][19] Despite possibly being one of the most abundant spiders around homes and buildings throughout New Zealand,[4] B. longinqua itself is not often sighted as it feeds at night and will stay hidden in its retreat during the daytime.[11][4][12] Furthermore, it generally does not go wandering into households in search of a mate as with other common species of Araneae.[12] When night falls, the grey house spider exits its burrow to tend to its web,[12] and then sit in wait of a meal.[2][3]

This species is a web-building spider meaning that it constructs its web in a calm and undisturbed place.[9] Thus making them wait for food to come to them and capture their food. An assortment of insects are preyed upon by Badumna longinqua, including; small psyllids, ants, and moths,[2][8] as well as some insects of considerably larger size than itself, like wasps, bees, and even bumblebees and cicadas.[12][2][8] However, usually making up over half of the diet is, as could be expected, a variety of flies.[7][2][8] Victims that make the fatal mistake of blundering into the sticky web are rushed at, bitten, and further entangled by the spider until unable to move or escape.[7][4][12] If this prey is caught during the day, the grey house spider retires back into the safety of its burrow, to emerge after nightfall and feast on its earlier catch.[4][12][19] Spiders feed by liquefying the prey through injection or regurgitation of digestive fluids into their prey to then proceed to suck the digested food.[9]

Parasitic wasps and flies can pose a risk to B. longinqua, but its greatest predator is the notorious hunting spider, Lampona, more commonly known as the white-tailed spider.[2][8] There are two species of Lampona in New Zealand and both seem to readily predate grey house spiders as a favoured dietary choice.[11][3][8] Along the Pacific Coast of California and presumably in other countries, grey house spiders are frequently preyed upon by the cosmopolitan long-bodied cellar spider or "daddy long legs" (Pholcus phalangioides), another very prevalent alien species[7] which is likewise common and introduced in New Zealand .[15][8] Many birds eat this species as well as some mammals (New Zealand Short-tailed Bats).[8]