GOOD MOTHER BUT DANGEROUS WIFE

The Nursery Web Spider (Pisaura mirabilis) is quite distinctive with a narrow abdomen and a white stripe on its cephalothorax (the front part with head and thorax combined).  They are very variable in colour but that stripe is always there.  It is often found sunbathing on a nettle or bramble leaf with four legs pointing forward and four legs pointing back.

This one, however, was resting in a watering can and I had to rescue it when I had filled the can.  It was all scrunched up into a ball and floating on the surface but unfolded when I put it down.  It's a handsome male as you can tell from the comparatively large pedipalps (like feelers) on the front end.

There are two more interesting things about this particular species of spider: how it mates and how it cares for its young.

The male catches something, probably a fly, and gift wraps it in silk before going in search of a female.  He then offers this tasty snack as a present to distract her and quietly mates with her.  When finished he has to leg it quickly or else he might find he has become the second course.  Females don't like to waste a tasty meal whether gift-wrapped or ambulant.

Unlike most spiders the female looks after her eggs and spiderlings.  She constructs a domed tent of silk - the nursery web - and places the cocoon containing lots of eggs in there.  She sits by them protectively and even stays after they hatch.  The spiderlings live off the yolk of their egg sac for a few days but when they start eating each other, mother despairs of them.  She leaves and the spiderlings disperse.

In summer you can often find these nursery webs at about knee height in long grass.

Photo: David Nicholls, Naturespot.