3-Oct-2017 La Center, Washington

Site location map. Click to enlarge.

Fall sampling has arrived! After barely making our species quotas in the dry heat of late summer, it's always exciting to collect in October. By then, days are cooler and autumn rains have begun, but there are enough consecutive dry days that collecting is still possible. And most importantly, we are usually able to collect many more species than our minimum daily target of twenty-one.

This day Rod Crawford and I headed south to La Center in Clark County, where a student's recent pitfall study in broccoli fields had provided Rod with interesting but incomplete samples from two adjacent gridspaces. Our goal was to raise the species total in each gridspace to at least twenty-one. Luckily, since we had a long drive to get there, accessible habitats in each gridspace were accessible within a few miles of the freeway.

Female Phidippus audax from shed

Our first stop was at a county reserve located at a convergence of agricultural land, forest and the East Fork Lewis River. I had little luck finding fallen open conifer cones to tap, but had some success sweeping riverside grass and collecting from the walls of a shed.

A formidable mantis...

The area was also good for some insect photo ops, including this European mantis (Mantis religiosa) that landed on me as I was walking down the road to the river. By its coloration, I'm guessing it had been spending most of its time on drying grass. Gardeners and farmers buy mantis egg cases and introduce these animals into their fields as pest predators. However, I am skeptical that they are effective since 1) they're generalist predators and so eat beneficial animals like bees and spiders as well as troublesome ones, and 2) like ladybirds, they have wings and don't stay put.

...and a decidedly unformidable woollybear

I also spotted my first woollybear (Pyrrharctia isabella) of the season, which was dashing headlong through the riparian grass.

Our second stop was at the Lake Rosannah Natural Area ("Mud Lake" on older maps) located at the lower end of the Allen Creek drainage. After collecting from gates and fences near the parking area, I walked the trail towards the lake and was happy to find open Douglas-fir (Pseudotsuga menziesii) cones next to the trail.

Female Gertschanapis shantzi

Cone tapping site by Lake Rosannah

Tapping 50 fallen cones produced only two spiders, a juvenile Phrurotimpus and a tiny, shiny dark-colored spider shaped like a theridiid. According to Rod, it turns out to be "Washington's first specimen of the extremely rare, minute palpless spider Gertschanapis shantzi (Anapidae), known from a few sites in California and Oregon"! If I had sampled more cones, perhaps I would have collected a male as well. But I was dissuaded by the poison oak (Toxicodendron diversilobum) growing through the forest litter, and didn't yet know I had found such a rarity.

Read Rod's account of the day here.

The lustrous leaves of poison oak.

Last blossoms of summer: Spiraea douglasii