Monday, July 4, 2011

Australian Redback Spider

Female Australian Redback Spider
Underside showing hourglass marking

It is Biosecurity Month and here at Kiwicare our ever vigilant staff noticed an unusual spider wandering across the factory floor. On identification it was found to be a female Australian Redback. This spider has a powerful venom and bite and has been known to cause death in rare occasions so we took care when collecting it and preserving it in 70% ethanol for id and reporting to MAF Biosecurity.

The Redback can be easily identified by the red marking on the back and a red hourglass shape on the underside of the abdomen.

Redbacks originated in Australia and are a cousin of the native Katipo. They have been spreading across New Zealand and are found as far afield as Otago and Bay of Plenty. I am not sure how common they are in Christchurch, it may be that this one hitched a lift on a container that recently passed through the facility.

What kind of doctors are like spiders?
Spin doctors!



2 comments:

  1. Technically, they are identified by by the hourglass on the underside only (if looking for colour clues) because juveniles have different colouration and can be deep red, even striped (laterally, not longitudally like the adult) white, yellow and brown.

    However - I would not be using my hands to flip over a spider like this! Incidentally, there are other spiders, at least here in Australia, like the St Andrew's cross, that have similar colouration to the juvenile I mentioned.

    In truth, the giveaway is the body shape - the bulbous pea-shaped abdomen attached to the cephalothorax (head/trunk combined). The St Andrew's, for example, appears more contiguous between these segments. North America has its black widow - no red - that is essentially the same in this regard.

    Redback webs are also very scrappy - usually containing lots of leaf and other litter like grass clippings. They are often between walls and the ground, or hedges and the ground - up to about 1 or 2 feet off the ground. They love hiding on the underside of things such as the handles on plant pots or the underside of garden chairs and benches.

    They do not move fast, are not that aggressive, and you could probably grab a pot and be within 2 inches of this spider and not get bitten - but don't try it.

    Chris.
    Where Light Meets Dark.

    ReplyDelete
    Replies
    1. Hello Chris,
      Thanks for the further info.
      Kind regards
      David

      Delete

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