Photo 1. A male beautiful jumper spider, photographed while stalking prey on a sunlit limestone rock. (Photo by M. Randić)

JUMPING SPIDERS

In the environs of Rijeka – on Mount Učka and at the foot of Mali Platak – we saw at first hand that on sunny winter days it is possible to find interesting representatives of the world of arthropods. Under stones in the grasslands there, we came across a variety of arachnids. Of the spiders we saw, the most frequent were the females of the beautiful jumper spider. While the females have a drab, greyish colour, the males are more brightly coloured and can mostly be seen during the warmer part of the year…

Jumping spiders (family Salticidae) are a large group of small-sized spiders, characterised by lovely colours and an ability to jump suddenly. Instead of spinning a web to hunt prey, these spiders catch prey by surprise, jumping on it and then killing it with a venomous bite. Jumping spiders are not dangerous to people, because their poisonous chelicerae cannot puncture human skin. As they like to stay in sunlit spots, we can often find them on drystone walls, rocks and the not-so-grassy edges of meadows. The male of the beautiful jumper spider   (Philaeus chrysops) stands out on the white limestone because of its bright red or orange abdomen, with a contrasting longitudinal black stripe down the middle (Photo 1). Populations of this spider can be found from the seashore up to the highest mountain peaks, most often where there are lots of stones and rocks on the ground.

M. R.