St Andrews cross spider

Appearance

Females of the species vary from 10 to 16 mm in size. Their glossy carapaces consist of silver, yellow, red, and black bands on their upper segment with two horizontal yellow belts beneath. Males of the species generally vary from 3 to 4 mm in size. They are brown and pearly coloured. St. Andrew's cross spiders rest with their legs oriented in pairs.

Distribution

The St Andrew's cross spider can be found mostly in rainforest margins, open forests, and heathlands of eastern Australia. They can also be found in the northern segment of the Northern Territory, in the northern segment of Tasmania, in the western segment of Western Australia, near Tedi River of Papua New Guinea, on the Malakula island of Vanuatu, and on Lord Howe Island. They construct medium-sized webs on low, shrubby vegetation.

Individuals tend to prefer closed habitats, with preferences being determined by foliage density and predator density. They avoid placing their webs within or between trees when there is bird presence. Juveniles are exclusively found in closed habitats, likely to avoid insectivores like birds and lizards and to find more favourable vegetation for building webs. "A. keyserlingi" may move into open habitats as subadults or adults, possibly due to requiring larger prey to sustain growth.

Habitat

The St Andrew's cross spider can be found mostly in rainforest margins, open forests, and heathlands of eastern Australia. They can also be found in the northern segment of the Northern Territory, in the northern segment of Tasmania, in the western segment of Western Australia, near Tedi River of Papua New Guinea, on the Malakula island of Vanuatu, and on Lord Howe Island. They construct medium-sized webs on low, shrubby vegetation.

Individuals tend to prefer closed habitats, with preferences being determined by foliage density and predator density. They avoid placing their webs within or between trees when there is bird presence. Juveniles are exclusively found in closed habitats, likely to avoid insectivores like birds and lizards and to find more favourable vegetation for building webs. "A. keyserlingi" may move into open habitats as subadults or adults, possibly due to requiring larger prey to sustain growth.

Reproduction

Mating takes place from summer to autumn and is a perilous occasion for miniature male St Andrew's cross spiders. Males settle on the upper segment of the web; some of them may be missing legs, caused by encountering inhospitable females. The male then materializes a mating thread within the web, which he uses to attract the hospitable female by oscillating the thread. The female then hangs her pear-shaped sac in a mesh of threads, frequently surrounded by leaves to camouflage the sac's greenish silk, because egg sacs are the target of wasps and flies.

Food

Prey of the St Andrew's cross spider include flies, moths, butterflies, bees, and other insects. The orb-weaver wraps its prey immaculately with silk before digesting, and smaller prey may be prioritized.