4-Dec-2017 Kent, Washington

Site location map. Click to enlarge.

Spider collectors in Europe report that male and female Ozyptila praticola (Thomisidae) can be found there every month of the year. It wouldn't surprise me if that were true here in Washington state was well, since I've collected adult O. praticola every month March through November. However, I have almost no O. praticola data for the months of December through February. A break in the wet winter weather this week gave me the opportunity to start remedying that.

My destination was the Kent - Covington - Maple Valley area in the southwestern corner of King County. I had collected juvenile O. praticola in Kent back in 2015, so I knew the species was in the area. On my way to my old collecting spot, I checked for fallen cones in the expansive business and industry parks on the north end of town. I found plenty of black pine (Pinus nigra) cones along the way, but none of them with open scales. As for my old collecting spot from 2015, groundskeepers had removed the cones.

First cone source: white pine

Erigone dentosa (bottom)
& Erigone TBD (top)

The same pattern continued until I got to the eastern edge of town, where I found a mature western white pine (P. monticola) growing next to a convenience store (the red pin on the map above). Many of its fallen cones had been run over by cars, but I was still able to find 20 intact ones to tap. They were wet and their scales were poorly opened, but they contained 7 spiders and 3 identifiable species of linyphiids: Tachygyna vancouverana, Erigone dentosa, and another Erigone species that I haven't identified yet. The sample was refreshingly free of introduced species. That doesn't happen often in the Seattle-Tacoma conurbation.

Second cone source: black pines

Ozyptila praticola juveniles

My next site was only about a mile further down the pike (the yellow pin on the map above) and consisted of a line of black pine trees growing behind a grocery store. The scales on these cones were also poorly opened, but that was no barrier to the spiders. I tapped 24 cones and collected 12 spiders and 2 identifiable species: T. vancouverana and O. praticola. At 10 spiders, O. praticola dominated the sample. However, they were, once again, all juveniles. Kent does not give up its mature O. praticola gladly!

With the sun setting, it was time to return home. Covington and Maple Valley will have to wait for another day.