Poecilopachys Australasiae
I stumbled across the most bizarre-looking spider today up at our bit of land on the Kaipara Harbour. It’s a Poecilopachys Australasiae and, as the name suggests, it’s a visitor from Australia. It was guarding an enclosed web that had a spindle-shaped egg sac suspended in the middle of it. I wonder what natural selection process caused it to develop these strange features?
Tags: Poecilopachys australasiae, spider
Yeah, they’re cute little fellas.
We came across them about twenty years ago, when we lived in Birkdale, on citrus trees.
Those processes that determine insect and animal formation is a real puzzle. It always seems that the symbiotic like relationship between organism and environment are so intimately and finely balanced, that it is hard to know what and which has the dominant input. Current environmental pressures on such a spider seem so miniscule. As a form of subterfuge, it’s hard to understand how that emerged from natural processes. Are these odd protuberances a genetic abnormality that became the norm because they deterred predators of spiders that had them?
I’ve got a pretty good idea of the mechanisms that would get a creature to look so weird but I haven’t seen anything in nature (around here anyway) that would make this little guy blend in. Perhaps there are some black and yellow and white spiky flowers in Australia? Or is it simply that the spikes look enough like eyes to make birds wary enough to give the spider an advantage?
I struggle to see how birds can miss them here in New Zealand if they are not put off by the ‘eyes’ - it’s got to be a bit of a handicap.
[edit] I’ve just done a search for citrus flowers and they are all white and yellow. Perhaps this has something to do with their colour scheme?
Man that looks weird alright and all things are naturally wary or afraid of the unknown so I’d say it was selected for survival benefits. Not sure why Aussie spiders seem to be so much more colourful than ours, I guess if their flowers are then it could be a camouflage thing - do birds see colour? Or is it just the shape that camoflauges. I still err on the side of the fear factor advantage thou - I remember being half way through a shower in an Australian campground and spotting this massive coloured spider in the top corner - I really do think if it’d moved (even a twitch) I ‘d have had a heart attack or at the least been a blithering wreck incapable of attack! I’ve never actually been hurt by a spider and they don’t threaten my survival so I wonder where my fear of them comes from, I’m guessing its a learned behaviour after seeing mum freak out as a kid.