Thursday, February 18, 2016

18-Feb-2016 Mill Creek, Washington

Sample site location (red arrow) in
relation to nearby Ozyptila praticola
collection sites
There's nothing that beckons like a sun break in winter, especially when the thermometer hits 50 F!  And since business took me to Mill Creek, a town I hadn't collected spiders in previously, I made sure to find an hour to tap some pine cones while there.

The tree, the ivy
My cone source was a white pine tree.  Whether eastern white pine (Pinus strobus) or western (P. monticola) I couldn't be sure because the bark wasn't well enough developed to tell.  I've found both species planted in the urban landscapes of Pugetopolis.  Whichever species it was, it was growing in a typical urban setting: surrounded by pavement and with an understory of pure English ivy (Hedera helix).

A cone suspended in the ivy matrix
I usually curse English ivy because, like the exotic invasive it is, it entirely snuffs out native plant species.  But I must admit that it did serve several useful functions in this case.  First, the dozens of cones that had fallen onto/into it escaped removal by groundskeepers.  And second, the cones suspended in the ivy matrix, which was up to 2 feet thick in some places (!) were fairly dry even though it had rained the night before.  Not so the cones I found on the ground, which tended to be muddy.  So I can hardly complain about the presence of the ivy, at least under this particular tree.

The haul
I tapped 50 fallen cones and collected 4 spiders, all juveniles.  Two were likely Ozyptila praticola (Thomisidae), the introduced crab spider that I'm working to determine the local distribution of.  The others were a theridiid and a Philodromus sp. (Philodromidae).  Not an exciting catch, but it does serve as another point on the O. praticola map.  Or at least, a fuzzy point.

Beautiful pine foliage blowing in the wind

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