21-April-2018 Edmonds, Lynnwood, and Mill Creek, Washington

Site location map. Click to enlarge.
Red pins: no O. praticola found
Blue pins: O. praticola confirmed with adult specimen

I've been so busy setting and checking cardboard live traps recently that I've hardly tapped any cones. This is because I set traps in places that generally don't have accessible fallen cones but where I still need to check for the presence of the introduced crab spider, Ozyptila praticola (Thomisidae). So as a rule, when I'm out trapping, I'm not tapping. On this day, however, I needed to chauffeur someone to and from an all-day event in Lynnwood, which put me in a highly developed part of Snohomish County where pines are a common landscaping plant. I've collected juvenile Ozyptila probably-praticola in Lynnwood and in nearby Mill Creek in previous years. Now I had an opportunity to (hopefully) confirm those IDs with mature specimens, and maybe document a few additional sites. And I could do that by once again tapping cones!

Brackett's Landing, Edmonds

Row of shore pines viewed from
nearby bluff. Railroad tracks in fore-
ground, Puget Sound in background

A shore pine cone

My first stop was the shoreline park Brackett's Landing. Though it was only 8:30 in the morning, the parking lot was already full of SCUBA divers readying their gear for a tour of the Edmonds Underwater Park. My destination was a little closer and a lot drier: the row of shore pines (Pinus contorta contorta) buffering the view between the restroom building and the railroad tracks. Cones were lying on a variety of substrates including wood mulch, pine litter and grass. I tapped 100 cones and collected 12 spiders from 6 families. All spiders but one were juveniles.

Female Pseudeuophrys lanigera,
ventral view

Female P. lanigera,
dorsal view

The spiders I tapped from these cones were typical for an urban cone sample in this region (Enoplognatha, Philodromus, Tenuiphantes, etc.), with one exception: Pseudeuophrys lanigera! I first discovered this European salticid in fallen pine cones in Mukilteo in 2015. Since then, I and others have found more P. lanigera in Seattle and Bremerton. You can read our paper about those discoveries here. This find in Edmonds, which is located between Mukilteo and Seattle, is consistent with those earlier findings. It also indicates that the initial discovery of the species in the fallen cone microhabitat was not a fluke. I didn't find any O. praticola in this set of cones.

Meadowdale Neighborhood Park, Lynnwood

Park woodlands habitat

Fallen Douglas-fir cones

My plan had been to tap Douglas-fir (Pseudotsuga menziesii) cones in the more naturalistic setting of Lynndale Park. There were no parking places to be found there, however, due to a little league baseball event. But soon enough, a little meandering brought me to Meadowdale Neighborhood Park, which featured semi-natural stands of Douglas-fir and western red-ceder (Thuja plicata). Tapping 75 Douglas-fir cones produced 8 spiders from 3 families. Cryphoeca exlineae (Hahniidae) and Tachygyna vancouverana (Linyphiidae) were identifiable to species. No O. praticola were found.

Mill Creek Post Office

Ivy with a buzz cut...

...made cones nestled in the
ivy's matrix more visible.

At this point I was not far from an urban spot in Mill Creek where I'd tapped juvenile O. probably-praticola twice before from fallen eastern white pine (P. strobus) cones. Since I still needed a mature specimen from there to confirm the species ID, I decided to give those cones one more try. After that, my plan was to continue eastward to Willis Tucker Park for another attempt at cone tapping in a less developed forest setting.

Groundskeepers had recently given a "haircut" to the very thick bed of English Ivy (Hedera helix) growing under my cone source. This had the great benefit of making cones much more visible and accessible. But it may have also chased the spiders away; I tapped 75 fallen cones and collected only one spider. But it was a good one! A female O. praticola!

Alderwood Mall, Lynnwood

Oh hail.

So much for plans! Just as I reached Willis Tucker Park, a soaking rain began to fall. I decided to head back to Lynnwood, but stop off in Tambark Creek Park along the way to see if it might be another good future spot for collecting. In the few minutes it took me to get there, the rain had turned to hail. Ah, spring!

Alderwood Mall cone source

Despite the foul weather just a few miles east, I was pleased to find that Lynnwood had remained dry. I decided to drive around the Alderwood Mall area in search of some "mall pine" (black pine, P. nigra) cones to tap. I didn't have far to look. A row of black pines growing behind a vitamin shop had dropped numerous cones onto a bed of pine needle litter and sparse English ivy below. The scales of most cones were at least partially open, which isn't always the case with fallen black pine cones. I tapped 50 cones and surprisingly got a result very like Mill Creek. That is, the only spider species present in the cones was O. praticola, this time represented by two females.

Magnolia against a glowering sky