page_title: Austracantha
section_title: Reproduction and life cycle
hierarchical_section_title: Austracantha / Ecology and behaviour / Reproduction and life cycle
caption_attribution_description: English: Austracantha minax egg sacs attached to a grass stalk and a flower
context_page_description: Austracantha is a genus of spider with a single species, Austracantha minax, commonly known as the jewel spider or the Christmas spider. It is a member of the family Araneidae and is endemic to Australia. They are relatively small spiders, reaching a maximum total body length of only around 12 mm for females, and 5 mm for males. Their abdomen has six distinctive projections that makes them easy to identify. They are predominantly a shiny black, with variable white, yellow, and orange patterns. Melanistic forms also occur during autumn. They are facultatively gregarious, and can be found in large aggregations of overlapping orb webs. They feed on small flying insects that get entangled in their webs. They are harmless to humans, though the webs can be a nuisance for bushwalkers. They are most abundant during the summer months.
context_section_description: After locating a receptive female, male jewel spiders will begin courtship by first attaching a "mating thread" from nearby plants to the edge of the female's orb web. It then positions itself in the middle of this thread and begins strumming it with their first and second pair of legs. The female will respond by moving towards the source of the vibrations, eventually climbing unto the mating thread itself. Once this happens, the male will wrap its legs around the female tightly and insert its pedipalps into the female's epigyne, transferring its spermatophores (silk packets containing sperm) into the female's spermathecae.
  A female jewel spider can mate with multiple males during a single reproductive cycle. If given the chance, the female will still readily mate with other males shortly after a successful mating. To prevent sperm competition, the successful male will defend the female shortly before and after mating. It actively drives away other rival males until the female enters a refractory period and ceases to be receptive to further matings. This usually happens an hour to a day after a successful mating, during which the female will herself aggressively attack and drive away all courting males.
  Females usually attach their egg sacs on vegetation and other surfaces near the edges of their webs (including grass blades, leaves, and twigs). They are usually bound longitudinally with loose lengths of silk, but they can sometimes be found dangling. The egg sacs are around 15 to 35 mm (0.59 to 1.38 in) in length and can vary in shape from circular to pointed at both ends. They are reddish brown to golden brown in colour, though rarely they may also be bright yellow. They are made from closely woven silk.
  The spiderlings overwinter within the egg sacs until early spring. Females reach sexual maturity at around the middle of January, while males mature earlier in the middle of December.
caption: Egg sacs attached to a grass stalk and a flower (Sydney, 1909)[16]
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