28-Nov-2015 Lakewood and DuPont, Washington

Locations of present and previous
Ozyptila praticola sample sites. Click to enlarge.

Last week I confirmed the presence of the introduced crab spider Ozyptila praticola (Thomisidae) in the city of Federal Way, Washington.  This day I looked for it in Lakewood and DuPont, which occupy what I have theorized may be the southern end of its local range.

Lakewood

Fallen white pine cones in Lakewood

Lakewood site

My Lakewood sample site was in the Tillicum neighborhood, which is sandwiched between American Lake and Joint Base Lewis-McChord.  Two western white pines (Pinus monticola) located along the edge of a suburban yard had dropped cones onto a variety of substrates including pine needle and oak leaf litter, English ivy (Hedera helix) and decorative stones. I tapped 51 cones and collected 9 juvenile spiders.  Most were Enoplognatha sp. (Theridiidae) and Phrurotimpus sp. (Phrurolithidae).  None were crab spiders.

DuPont

Next I drove about 5 miles further south to DuPont.  My hope was to tap cones dropped by the pines shading the sidewalks in front of the Amazon Fulfillment Center and Intel Corporation.  These trees were clearly visible from aerial photos.  What I found at the site, however, was that all forest debris had been removed from the ground beneath the trees.  This included cones.

DuPont site

Fallen black pine cones in DuPont

Returning to a shopping center that I had passed on the way to my preferred site, I discovered a row of black pines (Pinus nigra) planted as a visual buffer between the road and a parking lot.  Although most of the cones that had fallen there had also been whisked away by groundskeepers, a few had escaped that fate by rolling into an undeveloped lot.  And most had come to rest on leaf or needle litter, which is a habitat amenable to O. praticola.  But tapping 44 cones, I collected only 2 spiders.  One was a male Cryptachaea (Theridiidae), the other an unknown juvenile.  Again, no crab spiders.

This was not a very exciting cone tapping day.

Mt. Rainier was barely visible through the cold fog