Net casting spiders

(23 December 2016) Net-casting Spiders make a small web in the form of a blueish-white square net held by the front legs that can be stretched out wide. In order to have an aiming point, the spider often drops splashes of white faecal droppings onto the leaf or bark substrate over which it is poised. When an insect walks across this ‘target’, the spider plunges its net downward to envelop and entangle it. If successful, the spider silk-wraps the prey item, bites and paralyses it, and then feeds on it. If not used during the night, the spider will eat the net in order not to waste its valuable chemical components. Net casting spiders use their eyes to spot and catch the prey in the dark: their eyesight is better than that of cats and owls. Each night a large area of light sensitive membrane is manufactured within the eyes, and since arachnid eyes do not have irises, it is rapidly destroyed again at dawn to avoid overexposure to light.

A tripod, lang exposure time and a torch to highlight the spider and the net, creating a shadow of the spider on the leaf, are ingredients of a good film set. f/8 for enough depth of field, 1/25 is possible because of the tripod and ISO 200 as a setting with minimal noise, but a bit better shutter speed than ISO 100. The colour settings (white balance) have been adjusted to the torch. No flash light. And minimal torch light ion the subject, to reduce disturbance.