Nature Diary - Summer 06
Steve Gregory, Field Ecologist
A new spider for Little Wittenham Nature Reserve and for Oxfordshire
Autumn is the time of year when orb-web spiders mature and can be seen hanging conspicuously from the centre of their webs.
The common Garden Spider, Araneus diadematus, is a large orange spider that can be seen virtually anywhere. On the grassy slopes bordering the river we also have its close relative Araneus quadratus, which as its name suggests usually has four large spots on its body. This spider has the distinction of being the heaviest found in Britain (though others have much longer legs!).
This August I heard reports of a large black and yellow spider on Round Hill. This turned out to be the Wasp spider, Argiope bruennichi; the first verified sighting of this rare spider in Oxfordshire.
The Wasp Spider
Despite its very striking appearance it is easily missed. It spins its web low down between grass tussocks in rough grassland. The web is designed to catch grasshoppers which it feeds on. It is strengthened by a distinctive white zig-zag (known as a stabilimentum) running top to bottom through the web.
Until the 1970’s the Wasp Spider was known from a few sites on the south coast of England. Since then it has slowly moved inland, possibly as a result of climate change: to breed it requires hot summers and a mild winter.
Details of this first verified record for the county have been sent to the British Spider Recording Scheme . This information will contribute towards our knowledge of the biology of spiders, their habitats, seasonal occurrence and population dynamics.
The spiders on Little Wittenham Nature Reserve are well researched and over 250 different species are recorded (there are about 650 in Britain). Finding a spider new to the reserve is a reminder that species communities are not fixed but constantly changing in response to subtle changes that occur imperceptibly around us.
