2-May-2018 Lynden, Washington

Site location map. Pins show places I tapped cones in 2017.
Red and yellow indicate no or juvenile O. praticola found,
respectively, in cones (pins) or tree trunk moss (square).
Blue star indicates male P. lanigera collection site.

The small farm-oriented city of Lynden was Rod Crawford's and my destination this day. Having tapped cones at four locations in this northern Whatcom County enclave late last September, I didn't expect to see anything too different this time around. Boy was I wrong!

Male P. lanigera on
building exterior

The excitement began at our first stop at the Northwest Washington Fairgrounds (blue star on map above). After an uneventful start of picking spiders from the chain-link fence and some stacked concrete barriers, I moved on to building exteriors and came face to face with a male Pseudeuophrys lanigera (Salticidae). First discovered in North America by yours truly less than three years ago, the species appears to be rapidly expanding its range in the Pacific Northwest. In addition to the findings we've reported to-date, in March of this year Sean McCann found both male and female P. lanigera on the exterior of a building at the Vauncouver International Airport in Richmond, British Columbia. And just this week, a high school student in "the other Vancouver" here in Washington found what appears to be a male P. lanigera in her school's cafeteria. The latter ID is still pending, but it is clear that spider enthusiasts along the west coast should keep their eyes peeled for this tiny salticid.

Bender Fields cone source was a border
of planted Douglas-fir and red-cedar trees
paralleling Fish Trap Creek.

After sweeping marsh grass next to Fish Trap Creek, which borders the fairgrounds, we moved on to Bender Fields for my next surprise of the day. I had tapped 50 Douglas-fir (Pseudotsuga menziesii) cones there the previous September and found three identifiable species, all common linyphiids: Erigone aletris, Tachygyna vancouverana, and Tenuiphantes tenuis. The same species were present this day, as well another introduced spider, Lathys humilis (Dictynidae). I had collected L. humilis in nearby Blaine in February, 2017, so it's presence wasn't a really big surprise.

Penultimate female O. praticola
on a Douglas-fir cone scale, looking
very much like a conifer seed.

What did surprise me at Bender Fields was the presence of numerous penultimate Ozyptila probably-praticola (Thomisidae), the introduced European crab spider I didn't find anywhere in Lynden last year. Open cones being plentiful this visit (they were in short supply last September), I tapped 150 in hopes of collecting a mature specimen, but no dice. Still, I did collect 16 juveniles and penultimates, so Rod and I each brought home a penultimate to rear to maturity to prove the presence of the species.
UPDATE [17 May 2018]: The penultimate female I was rearing has molted to maturity. Ozyptila praticola is now confirmed in Lynden, Washington.

A little bit of moss...

Rod also collected one juvenile O. probably-praticola from leaf litter from the creekside edge of Bender Fields, but overall there were very few spiders in that microhabitat. With an eye towards finding him a more productive habitat as well as finding me some tree trunk moss to sift for possible O. praticola, we headed for the banks of the nearby Nooksack River.

...can hold so many Ozyptila.

Not for the first time this day, I had to wade through thickets of Himalayan blackberry (Rubus armeniacus) to reach my destination. In this case, my destination was a group of mature cottonwood trees (Populus trichocarpa) with mossy trunks. I was only able to collect half a sweep net-full of moss, but that small quantity harbored an astounding 42 juvenile O. probably-praticola. The thorny slog through the living barbed wire that is blackberry was very much worth the information I was able to gather from the moss on the other side.