Monday, January 8, 2018

7-Jan-2018 Spanaway, Washington

Site location map. Click to enlarge.
Blue pins: Ozyptila praticola confirmed via adult specimen.
Red pins: No O. praticola adults or ?praticola juveniles found.
One of the benefits of tapping fallen conifer cones is that they usually aren't too wet to sample unless a soaking rain falls. Chances of afternoon rain were high in the Spanaway area on this day, but I didn't think that enough rain had fallen the night before to make cones too wet for some morning tapping. As luck would have it, I was right, and managed to tap cones at two sites before the predicted rain began to fall.

Walmart

Young black pines along
the Walmart border
Fallen black pine and
Douglas-fir cones
In about the year 2001, a Walmart was built on the site of a former gravel pit in the south end of town. Subsequently, a double row of black pines (Pinus nigra) and Douglas-firs (Pseudotsuga menziesii) was planted along much of the property's northern and eastern borders. These trees are now large enough to produce cones, and I had no trouble finding 100 cones to tap. Although the cones' scales were only partially opened, they still produced 27 spiders and 5 identifiable species, mostly linyphiids. The most abundant species was Tachygyna vancouverana, with a total of 15 males and females.

Female Wubana pacifica
Wubana pacifica's white "butt spot"
Also present were two female Wubana pacifica, a species I've only tapped from cones once before but which I recognized immediately due to its white "butt spot".

Light rain was falling by the time I finished sampling at this location, so I delayed my lunch break and immediately began searching for another set of cones to tap. I hoped to complete one more sample before everything got too wet.

Power Substation

White pine at power substation
Lots of poorly-opened
white pine cones
Fortunately I found what I was looking for fairly quickly at a nearby power substation: a white pine tree (P. strobus or P. monticola) large enough to shelter me (and the fallen cones beneath) from the worst of the rain that was now falling in earnest. The cone scales were poorly opened here, too, but they were open far enough for small spiders. Still, I only found 3 spiders in the 50 cones I tapped, all T. vancouverana. I would have tapped an additional 50 cones, but the pouring rain brought my efforts to a halt.

I'm always curious to see whether I find the introduced European spider Ozyptila praticola at any given location. I didn't find any this day, or indeed in any of the other approximately two dozen sets of cones that I've tapped in Pierce County (see map above). If it's present in the county, it's highly localized.

It's that time of year...

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