What's That Bug? does not endorse extermination

Subject: Big beautiful spider
Location: North Dakota
August 20, 2012 6:10 pm
I’m not good at spiders! I’m actually a bit afraid of them, but recently I’ve become fascinated with this spider, who lives beside a bridge in North Dakota. She’s pretty big, about three inches. I’ve been calling her a wolf spider, but that doesn’t seem to be right. I’ve submitted pictures where you can see the patterns on her body, which I think are really interesting. Do you know what she is? Thanks!
Signature: Amanda

Fishing Spider with her Nursery Web

Dear Amanda,
We love your photographs.  This is a female Fishing Spider or Dock Spider in the genus
Dolomedes.  Fishing Spiders are in the Nursery Web Spider family, and they get that name because the females exhibit extreme maternal care of the eggs and spiderlings.  When the female Nursery Web Spider lays her egg sac, she carries it around in her chelicerae or jaws until she finds a suitable location for spinning her nursery web.  She continues to guard her spiderlings until she dies or until they disperse.  Fishing Spiders in the genus Dolomedes are named because many members in the family are closely associated with aquatic habitats and they can run across the surface of the water and they often dive beneath the surface of the water to escape predators.  There are even reports of Fishing Spiders diving beneath the surface of the water to capture small fish and tadpoles.

Fishing Spider guarding her Nursery Web

We enlarged one of your images to get a better view of the spiderlings.  We believe your spider might be Dolomedes tenebrosus, which according to BugGuide, is found in North Dakota.  It is one of the most northern ranging of the Fishing Spiders.

Fishing Spider Spiderlings

 

What's That Bug? does not endorse extermination
Location: North Dakota

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