Nursery Web Spider with Egg Sac


Nursery Web Spider – Pisaurina mira

Nursery web spider with egg sac

Pisauridae – Nursery Web and Fishing Spiders
Live adult male and female spiders macro-photographed at Georgia and northern Illinois.

These spiders resemble the wolf spiders (Lycosidae), but have a different eye pattern. Pisaurids have their eyes arranged in 2 rows, the posterior row slightly recurved, the median eyes in the second row slightly (if any) larger than the others. (Wolf spiders have eyes arranged in 3 rows).

Nursery web spider with egg sac

The egg sac is carried by the female under her prosoma, held there by her chelicerae and pedipalps. It is further supported by silk lines to the spinnerets. [1] She carries her egg-sac until near hatching. She then spins a protective web in which her hatchlings live until their first moult.

Nursery Web Spiderwith egg sac
This egg sac is about 15mm diameter

Before the eggs hatch, the female attaches the sac to a plant and then builds a web around it (below). When the eggs inside are hatching, the momma spider opens the cocoon and releases the hatchlings — then stands guard nearby. The hatchlings remain in the web until thier first moult. The Pisaurids forage for their food and build webs only for protecting their young.

Nursery web with spider hatchlings

Nursery web filled with hundreds of spiderlings

References

  1. Paul Hillyard, Private Life of Spiders (New Holland Publishers Ltd, 2007).
  2. Arthur V. Evans, National Wildlife Federation Field Guide to Insects and Spiders of North America
  3. Bugguide.net  Nursery web spider with egg sac Pisaurina mira
  4. Bugguide.net  Nursery web spider Pisaurina mira

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