Thursday, May 14, 2015

12-May-2010 South Whidbey Island, Washington

Site location (click to enlarge)
Nothing like a ferry ride to make a field day extra exciting, especially when the destination is an island.  And then when you unexpectedly find tappable pine cones at your destination, well, it doesn't get much better than that.

Sample site
Earlier in the year, Rod had helped a local homeowner identify a moth, and in return she kindly gave us permission to collect spiders on her family's property.  When we arrived, I was delighted to discover a stand of western white pine (Pinus monticola) growing just steps from the road.

The fallen cone microhabitat
The cones were laying in a wide variety of situations, including on bare sand, on grass and other herbs, and on needle litter both with and without adjacent understory vegetation.  It was hard to take a representative photo.

Tapping 60 cones, I collected 48 spiders and 14 species from 7 families.  Compared to my eastern Washington cone samples, where I'm lucky to collect 6 species per site, this sample was exceedingly rich.  Being in Puget Sound, I suppose it wasn't too surprising that 3 of the species were introduced.

Interestingly, the most numerous species in my cone sample was Neriene litigiosa (Linyphiidae).  Commonly called the Sierra dome weaver, this species is most often collected from vegetation or aerial webs, but also pitfall traps.  So far, this site remains the only place I've collected it from cones.

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