Clever jumping spiders

Lord Vetinari

Having noticed that jumping spiders seem to be able to jump horizontally on a vertical wall to catch their prey, I wondered if they can jump upwards and catch their prey. To be able to do this they would have to be very clever using their safety lines to pull them back towards the wall during the jump. Anyway I place a half drowned cleptoparasitic fly I'd caught on my bee houses about 25mm above a hunting jumping spider on the house wall. Instead of trying to flank the fly (which is what I thought it would do), it went straight towards the fly and jumped the last 15mm to successfully catch the fly. The jump did seem significantly shorter than when they jump down the wall for prey.
The spider turned out to be a male which have rather large chelicera/fangs.
Brian V.

The setup - a small cleptoparasite fly placed vertically above a jumping spider hunting on the house wall


The result - the spider jumped vertically up the wall about 15mm and caught the fly