Friday, January 8, 2016

6-Jan-2016 Discovery Park, Seattle, Washington

Site site location. Click to enlarge.
Daytime rain and overnight frost had been dissuading me from tapping cones for several weeks.  But with a few preceding nights above freezing and this day a sunny 48 F (~9 C), conditions were once again amenable to taking a winter cone spider sample.

Sample site
A western white pine (Pinus monticola) growing at the edge of a Douglas-fir (Pseudotsuga menziesii) woods in Seattle's Discovery Park was my cone source.  All of the cones I tapped were lying on needle-and-twig litter within the tree's drip line.

Fungus and a fallen cone
I tapped 50 cones and collected 20 spiders and 6 species.  Three were species I find commonly in Seattle-area fallen cones: juvenile Cryptachaea blattea (Theridiidae), juvenile Enoplognatha probably-ovata (Theridiidae), and female Tachygyna vancouverana (Linyphiidae).  However, the other 3 species in my sample were new to me.

Adult Blabomma californicum
Blabomma californicum epigynum
Almost half of the sample was comprised of Blabomma californicum (Dictynidae).  With females measuring 6 mm in length, this is by far the largest dictynid I've handled.  I'm more accustomed to the smaller dictynids found in webs at the apices of herbaceous plants, so finding (with the help of Rod Crawford - thanks Rod!) that these were dictynids was a surprise and learning experience for me.  Well, every cone sample is a learning experience, but some more than others.

I'm a linyphiid. Good luck IDing me.
I have 2 more species of linyphiids still to identify, but that will have to wait for another day.

Although a merry sun was shining, the constant north wind kept me chilled.  But it was apparently fine weather for ballooning for numerous spiders in nearby Douglas-fir trees.  Glistening strands of silk 1-2 meters long were stretched horizontally on the wind from the ends of branches on the sun-soaked south side of the trees.  Unfortunately I was unable to intercept any of the attached spiders, so I don't know who was responsible for the eye-catching display.

Juvenile Blabomma californicum. Until I knew what these were, I was
calling them "tigers", for obvious reasons.  Beautiful spiders.

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