Sunday, November 22, 2015

20-Nov-2015 Federal Way, Washington

Site map. Click to enlarge.
Continuing dry conditions made it possible for me to continue my search for the introduced crab spider Ozyptila praticola (Thomisidae).  My current theory is that the spider is present in the entire Seattle-Tacoma conurbation.  This area stretches from Everett in the north to DuPont in the south, and is bounded by the Snohomish River estuary and Nisqually River delta, two formidable natural barriers to the spread of Ozyptila praticola if the species isn't a strong ballooner and isn't getting an unwitting travel assist from humans (Those are two big "ifs" which I still need to research.).  Having found the species in Kent a few days prior, I jumped about 6 miles southwest to Federal Way for the present sample.

Lugubrious sample site
The fallen pine cone microhabitat
Black pines (Pinus nigra) planted along the southern and northern borders of a senior housing complex provided me with plenty of partially opened cones to sample.  I tapped 55 cones and collected 14 spiders and 4-5 species, plus some harvestmen.  Among the spider species present were "the usuals" I've been finding in this urban corridor: Tachygyna vancouverana (Linyphiidae), Cryptachaea blattea (Theridiidae), and yes, Ozyptila praticola!

O. praticola tapped from fallen pine
cones in Federal Way, Washington
While I was collecting, a steady stream of people walked by me on the narrow, unofficial path that ran between the fence and the senior apartment building.  One man asked what I was looking for, and upon hearing my answer was eager to show me an ugly sore on his leg that he insisted was from a spider bite.  He attributed it to the brown recluse, which I assured him doesn't live in our region.  Not surprisingly, people don't like hearing that they or their doctor may have made a mistaken diagnosis, and frequently stick to their opinion even though they never actually saw what bit them.  Much to this man's credit, he was willing to hear about alternate possibilities.

Mount Rainier was radiant in the distance

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