Night Orb Weavers

NIGHT ORB WEAVERS – by Steve Pearson

There are quite a few species of spiders that are active at night. The Araneidae spider family has a group of night orb weavers with quite a variety of species that vary in sizes and colours and distinctive patterns.

Each species has its own pattern on the abdomen. These spiders build at dusk and are the ones we are most likely to come in contact with and most commonly encountered in the garden at night and thus often called garden night orb web spiders. Most of the larger species need a big space to build their big really strong really sticky orb web and what better space than where we walk around our homes so they often use our walkways to put out their net just before dark to catch flying insects as they are attracted to house lights. Often People go outside at dusk to water the plants or just walk around and walk into a web with the spider in it. It is super sticky and sticks to them often with the spider stuck there too. Sometimes people try to brush it away but get bitten. The bite is worse than a bee sting. During the day the spider leaves its web up but hides itself at the end of one of the anchor lines. If it has had a big feed then it will not rebuild there for a period, real big feed could mean 2 or 3 weeks before they come back if they do. If they do not have a big feed they will be out the next afternoon at dusk to repair and rebuild in the same spot. If you want to see where they are during daylight tug lightly on the web and see where the anchor lines go. In the rainforest we have several species of smaller night orb weaver spiders that build smaller webs.

One really interesting one we call the Baggy-eyed Upside down rainforest night orb weaver spider Araneus praesignis family Araneidae. It has a Baggy-eyed pattern on its abdomen and it clings upside down to the ceiling of its daytime home. Camping upside down is a special adaptation for the ones that live in wet rainforest. They build a rain proof web shelter on top side of a V shaped leaf of a rainforest tree but then camps upside down on that web ceiling. When it is raining the leaf gets wet and the rain runs down the V of the leaf surface but the spider is safe and dry clinging to the ceiling above it all. The Baggy eyed Upside down rainforest night orb weaver spiders weave their web at dusk to catch insects for food but pull it down in the morning leaving no trace. That is really interesting as it has no web there to catch anything while it is away and there is nothing for Kleptoparasite spiders to move in and steal the catch. Pulling the web down also means you would not even know it was there but occasionally they catch a lot and have too good a night, too well fed and too fatigued to pull it down before daylight so you might come across the web and if you know how to tug the web you might find the leaf where the home is.

The Araneidae night orb weaver spiders are generally solitary and only come together for mating after the female has had a big catch, after a big feed so would be able to produce good eggs. The eggs are laid in a golden silky egg sack hidden on another tree away from its home tree. If you find it and monitor its progress you could be shocked by an unexpected happening, sometimes egg parasite wasps deposit their own young into the spider eggs and instead of spiders hatching out tiny wasps do.