Sunday, May 31, 2015

31-May-2015 Northeast Seattle, Washington

Site location
A few weeks ago, while I was tapping fallen cones under the lone pine in a northeast Seattle parking lot, one of the locals invited me to also tap the Douglas-fir (Pseudotsuga menziesii) cones lying under the neighboring hedge.  I passed on the opportunity since I was strapped for time that day.  But once I realized that my pine cone sample contained several penultimate Ozyptila (Thomisidae) females, I was eager to return after enough time had elapsed that I might find some mature specimens.

Sample site. Note 'lone pine'
in distance on right.
The fallen cone microhabitat
Many hundreds of Douglas-fir cones lay beneath the hedge bordering the parking lot, their parent trees growing on the other side of the border fence.  Most of the fallen cones on that side of the fence had been removed by maintenance workers, so I was sampling from a long, thin island of cones.

Ozyptila praticola epigynum
Female O. praticola
I tapped 50 cones and collected 8 spiders and 3 species, all introduced from Europe.  And yes, one was a mature female Ozyptila: O. praticola!  I presume that the juvenile Ozyptila I collected today and a few weeks ago under the nearby lone pine are also O. praticola since their coloration and patterning were the same as the female, but of course there is no way to know for sure. Rod Crawford first collected this species in Washington in 1976 from leaf litter on the University of Washington campus.  I had tapped the species once before from fallen Pinus strobus cones in Seattle's Green Lake Park.

Female Tenuiphantes tenuis
T. tenuis epigynum,
partially obscured
The other identifiable species in today's sample were Enoplognatha thoracica (Theridiidae) and Tenuiphantes tenuis (Linyphiidae).  I recently tapped both species from fallen pine cones in Seattle's Woodland Park.

Known distribution of Ozyptila praticola. Adapted from a
British Arachnological Society

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