Thursday, April 9, 2015

25-Mar-2011 Green Lake Park, Seattle, Washington

Site location
2011 was the year I began intensively sampling pine cone spiders in Washington state -- 42 sites by the end of the year!  Before 2011, I'd tap cones if there happened to be any at the sites I was assisting Rod Crawford in sampling.  But starting in 2011, Rod agreed to locate our sampling sites in places where ponderosa pine (Pinus ponderosa) was thought to occur.  This way I could tap cones more consistently.

Tennis court & pine cones
Our first sampling location of the year, Pilchuck Tree Farm, reportedly contained ponderosas, but we were unable to find any.  A few days later, though, I found a small grove of eastern white pines (Pinus strobus) on the west side of Seattle's Green Lake Park and tapped 32 spiders from 85 fallen cones.  The 2011 pine cone spider sampling season had begun!

Pinus strobus cone
If finding introduced species had been my goal, I couldn't have collected in a better spot.  Three of the 4 identifiable spider species I collected were introduced, as was the species of pine I collected them from!

Known distribution of Theridion tinctum.
Adapted from a
British Arachnological Society
Presumably the P. strobus trees had been deliberately planted in the park (one had an identifying plaque on it), but the Theridion tinctum (Theridiidae), Ozyptila praticola (Thomisidae), and Philodromus dispar (Philodromidae) spiders I tapped from the cones were probably the descendants of passive stowaways on transatlantic ships that had docked in Seattle or Vancouver, British Columbia.

Stay tuned for reports of the 41 other pine cone spider collecting events from 2011!

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