I have spent most of last week absolutely fascinated by a nursery web spider that I found in the garden. She had made whats called a nursery tent in one of my heather shrubs and every day I went out to see her and try and learn more about her.
Nursery web spiders (Pisaura mirabilis) are named for their habit of lashing leaves together as a shelter for newly hatched spiderlings, which they watch over until they finally leave their nursery tent.
They are up to 15mm long and have a narrow body ranging from grey to brown in colour. There is a pale stripe just behind the head, and the sides of the abdomen are also pale coloured. The top of the abdomen also features a leaf shaped marking.
They are commonly seen between May and July and like to sunbathe by typically hold their front two pairs of legs together pointing forwards. They are great hunters and feed on flies and other small insects but instead of making a web they use quick sprinting and strength to overpower their prey.
During mating the female spider will unfortunately sometimes attempt to eat the male after mating. To reduce the risk of this happening, the male gives the female a fly/insect as a gift wrapped up in silk thread. Sometimes however this gift is fake to fool the female but she is able to detect it and the male may not live to tell the tale.
The female carries her eggs in a ball shaped sack that she carries around in her fangs. Just before the babies hatch she builds a silk nursery tent and puts the egg sack inside for protection. They will hatch out of the sack and into the tent. She will then watch over her spiderlings until their first moult.
I was so fascinated by the amount of parental care she gave. She never left the spiderlings side and guarded it with her life. I was even more amazed when it started to rain and I noticed that she had put up a waterproof canopy over her nursery tent for extra protection. Those spiderlings were well looked after and kept cosy, safe and dry all week.
Today the last last spiderling has left the tent and the mum has gone too. I’m sad to see them go but happy they are all roaming free around the garden; and am glad I was able to watch and learn more about her.