Flower Spider Eyes

Thomisus spectabilis

This is a follow up to yesterday's blip, about spider eye patterns, in the eye series.

Here you see a ridge across the back of the spider, housing the eight eyes in a line, four of the eyes pointing forward, two pointing up and two pointing to the rear. Quite a strange and unique layout.

This arachnid has adapted to ambush techniques. It has camouflaged itself to blend into the white flower head and pounces on the unexpected flying insect when it lands. Its peripheral vision through its secondary eyes is poor, but good enough to tell when an insect approaches. Its two forward facing eyes have a much keener vision to direct the attack.

This arachnid is very difficult to spot and unless you are specifically looking for her, you will never come across this spider by accident. I only found this one as my attention was drawn by a rather large butterfly hanging under the bloom, the other end of which was firmly clamped by the spiders jaws. The ambush was only a minute or so old, as the butterfly was still moving.

This spider does not pick on insects its own size, preferring to bully butterflies many times larger. But, it is hardly a fair fight though. What is the defenseless butterfly supposed to do, flap its wings and beat the spider with its nectar sucking proboscis!

Update - image replaced with CS5 stack 300 bit version, much sharper!

Dave