Tuesday, May 24, 2016

23-May-2016 Auburn, Sumner & Orting, Washington

Site location map. Click to enlarge. Red pins: Ozyptila
not found; Blue pins: O. praticola confirmed.
Many of my recent searches for the introduced crab spider Ozyptila praticola have been dedicated to finding the northeastern extent of its local range.  For a change of scenery, I decided to shift my efforts southward this day.  Ozyptila praticola doesn't appear to have spread southwest of Federal Way into Tacoma or points beyond, but how far it might range southeast of there remains unknown.  My plan for the day was to begin sampling in Auburn, then follow the White River and Puyallup River valleys south into Sumner and Orting.


Auburn cone source
Fallen Scots pine cones
Three Scots pines (Pinus sylvestris) growing in the back corner of a suburban parking lot provided my first set of fallen cones for the day.  Tapping 50 of them, I collected 7 spiders and 3 species.  The most numerous species present was none other than O. praticola, with one each of a female, a male and a juvenile in the sample.


Sumner cone source
Tiny Scots pine cone and even
tinier female O. praticola
Scots pines again were my cone source in Sumner, this time located in the heart of the city on Main Street.  I tapped 50 cones and collected 4 spiders, all of them O. praticola!  Only once before, last November in nearby Kent, have all the spiders I tapped from a cone deposit been O. praticola.


Orting Doug-fir cone source
Orting shore pine cone source
I tapped 50 Douglas-fir (Pseudotsuga menziesii) cones from the south end of the business district and collected only 1 spider, a juvenile Philodromus (Philodromidae).  Just south of the city limits I tapped 50 shore pine (Pinus contorta var. contorta) cones and collected 3 juvenile linyphiids and 1 juvenile Enoplognatha (Theridiidae).  In other words, no O. praticola.  I would have liked to have tapped cones in at least one more spot in Orting, preferably two, but I unfortunately ran out of time for the day.

There's more sampling to do before the southeastern extent of O. praticola's range becomes clear, but this day provided some useful information.

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