By Kay Birkinshaw
The word ‘extraordinary’ is widely overused. Not though when it comes to Nature. For no matter how much time is spent in the bush, there is always something new to discover.
Two weeks ago Landcare was working on the edge of a gulley in Arcadia when we came upon an unknown phenomenon high in a tree. Eight egg sacs bound and strung together by thick yellow web. The egg sacs were elongated, and about 5cm in length.
A mystery to us, but luckily with a reverse-search, not to the experts on the internet. The eggs belong to a spider endemic to forests along Australia’s east coast, the Ordgarius magnificus, or Magnificent Spider.
The female (up to 2.5cm), weaves up to seven of these egg sacs over several nights, an amazing feat, as they each contain up to several hundred eggs. She then usually dies during winter, while the spiderlings will hatch around late Winter/early Spring and balloon away. However this is not their only extraordinary behaviour.
The arachnid also has the nickname of the ‘bolas spider’. The female spiders spin a short line of silk with a sticky globule at the end.
On detecting the wing vibrations of a moth from the family Noctuidae, the spider emits the pheromone of the female moth and begins swinging the web in a circular motion. The male moths, drawn towards the scent, are hit and trapped. Such extraordinary skill from such a tiny spider!
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