Trees home to a colony of weaver ants with their nests that resemble ketupat wraps are noticeably free of other small invertebrates. Only creatures with biochemical defences potent enough to ward off these ferocious hunters are safe, but for this caterpillars, unpleasant-looking spines don't seem to be enough. Ducks, even stinky ones, are defenceless and hence must endure the double bite of these ants which first clamp their mandibles onto cuticle or skin to create a puncture that is sprayed with formic acid from their abdomen.
Some spiders though have managed to carve a niche in this dangerous territory. At least one jumping spider in the genus Myrmarache has developed cephalothoraic constrictions that mimic the narrow waistlines of the kerengga and even behavioral modifications that reinforce the impression of an antennae-waving foul-tempered subject. Pheromonal signals are thought to aid the spider from receiving undue notice from the objects of its homage. A different spider copies the weavers less unconvincingly but still well enough to lure them to a crabby fate at the end of a silk line. Both the Salticid and Thomisid remain elusive to me, as my duck is easily dissuaded from a long squat under infested trees by the ardent attention of an army of amazons.
Are ant-mimics cool? I did a post on Myrmarachnes a while back. Ants and spiders are just plain strange!
http://other95.blogspot.com/2007/09/ant-spider-you-decide.html
Posted by: kevin z | 02 March 2008 at 10:42 AM