The Nursery web spider (Pisaura mirabilis) is the spider of this sunday. A common, yet striking spider. Nursery web spiders may vary in colour, but are always recognizable by the light yellow stripe in the middle of their prosoma (first body segment) and the lighter markings above the eyes. Striking are also their mating and parenting behaviours.
The nursery web spider takes the saying ‘the way to a man’s heart is through his stomach‘ almost literally. Except that it is the females that want to be fed before any love-making happens. Where zebra spider males have to dance to win over a female, nursery web spider males have to wrap up something delicious and offer it as a gift to get the girl. And unlike the zebra spider, who only gets rejected when he fails, the male nursery web spider faces the death penalty when unsuccessful! Females have no problems with eating their prospective mate. And, according to recent research, this has nothing to do with hungry females, because well-fed females will eat their mates as often as famished females do. So for the male spider it is essential to give an attractive and edible nuptial gift. The female will be distracted by the gift and the male can mate with her. Even then he has to be careful, some males ‘play death’ (also called thanatosis), and keep a close eye on when she is finished eating – so he can make a clean exit! Of course, lying and cheating also occur under spiders. Some males may wrap a inedible gift like a leaf, and some females will run away with the gift without so much as a thank you in return!
Assuming copulation was a success, when the time has come to lay eggs, the common name of the spider suggests what happens. The female forms an egg sac or cocoon and carries it around with her fangs. She then creates a web – the nursery web, where she hides inside until the babies are ‘born’. The mother cares for and defends her young until their second moult. She might ward off predators and when the web is disturbed (due to bad weather for example), she repairs it. This type of caring is pretty remarkable for a spider. That is why its Latin species name is ‘mirabilis’, meaning marvellous or extraordinary.
I have to agree with the one who named the spider: they are indeed extraordinary!
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