Friday, August 18, 2017

16-Aug-2017 Mount Vernon and Bellingham, Washington

Site location map. Click to enlarge.
Ever since finding juvenile Ozyptila that were patterned like praticola at two sites in Bellingham last November, I've been wanting to return to search for adult specimens. I wanted to know conclusively whether this introduced thomisid was present in Whatcom County's biggest city. It seemed likely, given Bellingham's situation along Interstate 5 and its proximity to British Columbia's southern reaches, where O. praticola has also been found. This would be the day to find out! But first, on my way north from Seattle to Bellingham, I stopped in Mount Vernon and Bow to take a few more samples in Skagit County; I have yet to find O. praticola (or any Ozyptila) in fallen conifer cones in Skagit County.

Mount Vernon & Bow

Anderson Rd site
Lots of cones & litter under the shrubs
On past trips north I'd noticed a row of pines growing just east of the freeway near the Anderson Road exit. Upon closer inspection this day, I found that groundskeepers had removed all of the cones and needle litter from beneath them. But it didn't take long to find "greener pastures" on the other side of the freeway: black pines (Pinus nigra) planted along a parking lot perimeter. Groundskeepers had been busy there too, but hadn't gone so far as to remove cones and litter from beneath the shrubs.

Zodarion collection sites.  Blue = Zodarion rubidum adult;
Yellow = juvenile Zodarion 
I tapped 50 cones and collected 37 spiders from four families. Most were juvenile Steatoda (Theridiidae) and Philodromus (Philodromidae). The only identifiable species was Tenuiphantes tenuis (Linyphiidae). By far the most interesting spider in the sample was a juvenile Zodarion (Zodariidae), presumably Z. rubidum. This is the farthest north I've found this rapidly spreading introduced species. I also sifted pine needle litter, but didn't find anything new. I found no O. praticola in either microhabitat.

Bow Hill Rest Area
Bow Hill Rest Area along Interstate 5 provided another convenient spot to tap cones in Skagit County. The facility is situated in a fairly natural forest fragment dominated by western red-cedar (Thuja plicata) and Douglas-fir (Pseudotsuga menziesii). Nevertheless, the 50 Douglas-fir cones I tapped produced only two harvestmen and two juvenile linyphiids.

Bellingham

Lincoln St. site
Since I already knew that Ozyptila could be found at the two Bellingham sites I had sampled previously, I decided to intensively re-sample those sites before looking for new ones. My first stop was the western white pine (Pinus monticola) growing on Lincoln St. near the Interstate 5 underpass. Except for the need to wade through thorny Himalayan blackberry (Rubus armeniacus), I had no trouble finding 50 fully opened cones to tap.

Female Steatoda bipunctata
Those 50 cones produced an astounding 100 spiders, 64 of which were the introduced Steatoda bipunctata (Theridiidae). I also collected two female Eratigena agrestis (Agelenidae), commonly known as hobo spiders. Juvenile agelenids aren't uncommon in the fallen cone microhabitat, but this is the first time I've collected mature E. agrestis. I suspect the reason is that most cones that I tap don't provide large enough hiding places for Eratigena adults, which have body lengths of 11-15 mm (legs not included). As for O. praticola, I again found but one juvenile spider at the Lincoln St. site. My plan had been to sift litter if I didn't find an adult specimen in the cones, but I decided against it unless my second Bellingham site proved equally unhelpful. The reason was the poor dog on the other side of the fence that had been barking for the past hour and a half. I was sure that I, it and its neighbors would enjoy a reprieve.

This unassuming site on James St. ...
...harbored this male Ozyptila praticola
Moving on, I was pleased to find that the western white pine at the intersection of Whatcom Creek and James street also had numerous fully opened cones beneath it. I tapped 50 cones and collected 24 spiders from 5 families. Only two species were identifiable: T. tenuis and, O. praticola! So now we know with certainty; Ozyptila praticola is indeed present in Bellingham.
Status of Ozyptila praticola in western Washington. Blue, yellow, or red
indicate adult O. praticola, juvenile Ozyptila sp. or no Ozyptila found, respectively

Wednesday, August 9, 2017

8-Aug-2017 Bainbridge Island, Washington

Site location map. Yellow pin marks Harborview Drive site.
Click to enlarge.
Smoke from wildfires in British Columbia precluded a trip to the gridspace of interest to Rod, so I took a solo trip to Bainbridge Island (Kitsap County) to continue my search for the introduced European thomisid Ozyptila praticola. So far I haven't found any O. praticola on the nearby Kitsap Peninsula, but it is present on Vashon Island five miles to the south of Bainbridge Island. Both islands are connected by frequent ferry traffic to Seattle, where O. praticola is now common.

Sampling site on Harborview Dr.
The fallen cone microhabitat
Almost immediately after disembarking from the ferry, I found a nice cache of fallen cones to tap on Harborview Drive. The cones were a jumble of Douglas-fir (Pseudotsuga menziesii) and black pine (Pinus nigra) cones intermingled with Douglas-fir and madrone (Arbutus menziesii) litter.

Juvenile Ozyptila (?praticola?)
O. praticola in western WA. Blue,
yellow & red pins indicate adult, juvenile
or no O. praticola found, respectively.
I tapped 100 cones and collected 26 spiders. Most were Cryptachaea blattea (Theridiidae), but two were juvenile Ozyptila. They look like O. praticola to me, but unfortunately I can't definitively identify the species from juvenile specimens, so a return trip with litter sifting equipment in tow will be required.

The other four Bainbridge Island sites I sampled produced more C. blattea as well as juvenile specimens of Tegenaria, Tenuiphantes, Philodromus, and Phrurotimpus. In all, very typical for fallen cones in urban western Washington.

Seattle skyline seen through the milky haze of wildfire smoke from the
deck of the M/V Tacoma.


Saturday, August 5, 2017

30-July-2017 Ferbrache Unit, Washington

Site location map. Click to enlarge.
With choices of productive sampling sites dwindling rapidly due to summer heat and dryness, Rod Crawford and I returned to a favorite late-season region, Grays Harbor County. Our main collecting site had the interesting name Ferbrache Unit, which I kept confusing in my mind with Fibonacci, as in the mathematical sequence. The area consists of Chehalis River sloughs, forest remnants and agricultural fields managed for waterfowl. My source of fallen cones was the one and only Sitka spruce (Picea sitchensis) growing on the forested edge of one such grassy field.

Rod dwarfed by the Sitka spruce and
its encircling jungle.
Looking across grassy field
at the giant Sitka spruce.
The tree was a giant and sported a massive skirt of Himalayan blackberry (Rubus armeniacus) and coastal manroot (Marah oregana or M. oreganus). The latter resembles the edible cucumber and belongs to the same family (Cucurbitaceae), but is apparently not edible.

First set of tapped cones returned
to the grassy field
Numerous cones had fallen on the grassy field, so I tapped 57 of them while Rod beat the few reachable spruce branches and the tree's skirt of foliage. My efforts resulted in only one juvenile spider.

Fallen cones near tree base made up
the second set
By the time I was done with that first set of cones, Rod had made a big enough hole in the wall of green (a machete would have been useful!) for me to worm my way through to the trunk of the tree.

Inside the manroot tangle
I was pleased to find vast quantities of cones under the pleasantly green and less-dry tree canopy and manroot tangle. I tapped 100 cones from that cache and collected 11 spiders and a few neobisiid pseudoscorpions. Compared to the lone juvenile spider I'd tapped from the "field" cones just a few yards away, this was a bountiful result.

All eleven spiders were juvenile except for a male and female Ceratinella (Linyphiidae) which didn't immediately match any species Rod was familiar with. Two of the juveniles were Metallina (Tetragnathidae), a genus I'd never found in fallen cones before. In fact, I rarely find anything from the family Tetragnathidae in fallen cones. Rod also collected many juvenile Metallina in his Ferbrache Unit sweep samples.

Read Rod's account here.

A field of peas across the road from the Ferbrache Unit.

Monday, July 24, 2017

18-July-2017 North Mountain, Washington

Site location map. Click to enlarge.
Since habitats on the east side of the Cascades are now too dry to be productive, Rod Crawford and I decided to head north to North Mountain, a mid-elevation site near Darrington in Snohomish County. We collected in the area in May of 2016, but at lower elevations. I was excited to reach to fire lookout atop North Mountain and take in the views of Whitehorse Mountain, Mount Baker and perhaps even get a glimpse of Glacier Peak. Oh, and collect spiders there, too...

Rod on final approach to the
fire lookout.
Mt Baker as seen from the lookout. The
view was hazy due to moist marine air.
After some confusion as to which road was the one leading to the lookout, we arrived at the locked gate and continued the final 1.5 miles on foot. It was a hot and somewhat humid hike, but a refreshing breeze was blowing through the lookout, which was under renovation and therefore had no windows. The views were just as stunning as I'd hoped.

But to work! After feasting my eyes on the scenery, I came back down to earth and set about tapping Douglas-fir (Pseudotsuga menziesii) cones near the base of the lookout. Except for a few harvestmen, however, those cones were arachnid-free.

Female Orodrassus canadensis
guarding her egg sac.
Female Pardosa mackenziana with
egg sac
The renovation work on the lookout meant that there were pieces of wood scattered about, so I next began looking beneath them for spiders. I didn't find many, but what I found certainly made the effort worthwhile. One wooden post on a concrete slab was sheltering a male Cybaeus reticulatus (Cybaeidae) and a female Orodrassus canadensis (Gnaphosidae). When I rolled the post aside, the top of the Orodrassus' nest-refugium got pulled off. This left her and her egg sac visible for a nice photo. I also found a few female Pardosa mackenziana (Lycosidae) under stones in a roadside outcrop a few hundred feet below the lookout.

Male Misumena vatia stepping onto
draglines that led to...
...a female Misumena vatia eating
a fly.
Big swaths of goatsbeard (Aruncus dioicus) were in full and glorious bloom along the roadside, so while Rod searched for conifer litter to sift, I began examining goatsbeard inflorescences. Not surprisingly, everyone's favorite crab spider Misumena vatia (Thomisidae) was numerous therein and conspicuous. I spent quite some time observing a male traveling on draglines between two adjacent inflorescences. Each inflorescence had an actively-feeding penultimate female near its apex.

Clubiona pacifica nest in goatsbeard
leaflet
Opening the Clubiona pacifica nest
made in goatsbeard leaflet
As fun as it always is to watch Misumena vatia, the really exciting, novel observation of the day came as Rod and I began our walk back down to the car. As Rod was diligently sweeping roadside herbs, I was quite honestly just enjoying a leisurely downhill ramble while photographing the occasional bee or spider in the nearly endless stream of roadside goatsbeard. That's when I noticed that something had folded the end of a goatsbeard leaflet into a neat, triangular package.

Opened Clubiona pacifica
nest after removal of female.
Clubiona pacifica nest in alder leaf
Upon opening it, we discovered a female Clubiona pacifica (Clubionidae) and her egg sac inside! Water droplets on the inside of the silk-lined package indicated that this was perhaps a moisture-retention mechanism as well as a predator control device.

Clubiona pacifica juvenile in silken tube
Shortly thereafter I spotted another triangular C. pacifica nest, this time made from an alder (Alnus) leaf. I also found a third, albeit juvenile Clubiona in a tubular silken structure in a goatsbeard leaflet that had been folded in half lengthwise.

Lower Doug-fir cone site
Productive Doug-fir cones
Heading back down the mountain, we stopped in a stretch of mature Douglas-fir and red-cedar (Thuja plicata) forest where Rod spotted some old stumps and downed wood he wanted to tap. I decided to take another crack at tapping Doug-fir cones, and this time had some luck. I tapped 100 cones and collected 16 spiders from 3 families. At 7 individuals, Cryphoeca exlineae (Agelenidae) dominated the sample and was the only identifiable species present.

Read Rod's account here.

A female clodius parnassian (Parnassius clodius) near the
North Mountain lookout

View of Whitehorse Mountain as seen from a clearcut on North Mountain.
Fireweed (Chamaenerion angustifolium) in foreground.

Thursday, July 20, 2017

16-July-2017 Granite Falls and Lake Roesiger, Washington

Collection sites of mature Ozyptila praticola (blue) and
O. pacifica (yellow). The red pin marks the location
of Granite Falls. Ozyptila pacifica data courtesy of
Burke Museum of Natural History and Culture.
Back in May, 2016, I tapped pine cones in Granite Falls for my ongoing study of the distribution of the introduced crab spider Ozyptila praticola (Thomisidae) in Washington state. Frustratingly, what I found there were juvenile Ozyptila. Although I suspected that they were O. praticola, I can't rule out the possibility that they were the native species O. pacifica (or some other species) since the Washington ranges of O. praticola and O. pacifica overlap (see map, right). I returned to Granite Falls this month in hope of collecting mature Ozyptila.

Site location map. Click to enlarge.
I tapped cones at two sites in Granite Falls, then drove south to Lake Roesiger Park to tap an additional two sets. Both locations are in the foothills of the Cascade Mountains. I'm looking to see if there is evidence that O. praticola has crossed that threshold.

Granite Falls

Pine cone source at car wash
Cozy nest of pine cones and needles
My first site in Granite Falls was the car wash on the east side of the business district. I had eyed this spot numerous times as I passed it on the way to Mountain Loop Highway and the innumerable hiking destinations beyond. The site has a planting strip that includes a black pine (Pinus nigra) tree surrounded by dense shrubs. Fallen needles and cones get ensconced in the shrubs, escaping removal by groundskeepers. I tapped 110 well-opened cones but collected mainly juvenile harvestmen (18!). Of the 7 spiders present, only Platnickina tincta (Theridiidae) was identifiable to species and the only crab spider in my sample was a Philodromus. Although spiders were relatively few there, I certainly enjoyed friendly conversation (and permission to continue!) with the owner of the car wash and others who happened by as I was working.

My second site in Granite Falls was in a residential area a few blocks from the car wash. I tapped 100 fallen Pinus monticola cones that had come to rest under a rhododendron hedge and collected 38 spiders from 6 families. Four species were identifiable, but the most common spiders were juvenile Tegenaria (15) and juvenile Steatoda (11). The Ozyptila count here: 1 juvenile and 0 adults. That's even more frustrating than the 3 juveniles I collected in 2016. It's the curse of the juvenile Ozyptila! I decided it was a good time to stop for a delicious and very satisfying late lunch at Barbeque Bucket before proceeding to Lake Roesiger.

Lake Roesiger Park

Site 1 at Lake Roesiger Park
I tapped my first set of Douglas-fir (Pseudotsuga menziesii) cones beneath a small grove of trees right by the lakeshore. It was quite pleasant to smell the fresh lake air and hear people frolicking in the water as I tapped 100 cones. The exercise produced a multitude of harvestmen but only 9 spiders, most of which were Cryphoeca exlineae (Agelenidae).

Site 2 cones on needle and
maple leaf litter
Site 2 at Lake Roesiger Park
My second set of cones came from the forest edge opposite the parking lot with respect to the lake. Here, 50 tapped cones produced only two juvenile spiders, a Callobius (Amaurobiidae) and a gnaphosid. I found no Ozyptila in either set of cones.

Monday, July 17, 2017

12-July-2017 Ruby Creek, Washington

Site location map. Click to enlarge.
Although it was getting late in the dry season for trips into the ponderosa pine belt, Rod Crawford and I decided to make one last foray. Our destination was the Ruby Creek watershed in Chelan County. In retrospect, we should have selected a higher elevation site; after a solid day's work, we had collected only 17 or 18 species. The habitats were just too dried out. And unlike in recent weeks, my cone samples didn't contribute even one species to the site list this time. However, I was able to take three full cone samples and one partial one. Each of them contributes to our knowledge of which spider families use the fallen cone microhabitat during the dry season. Data points aren't always individually flashy, but together they do paint a picture. Or so we hope.

Northwest End of Tronsen Ridge

Fallen Doug-fir cones on
ridgetop roadside
Fallen ponderosa cones
under ceanothus shrub
Our first stop was on the ridge separating the Ruby Creek and Little Camas Creek watersheds, elevation about 3,660 feet. This little ridge is itself part of the larger Tronsen Ridge. Tronsen Ridge in turn is part of the Wenatchee Mountains, the range in the Cascades that separates the Yakima River and Wenatchee River watersheds.

The introduced sulphur cinquefoil
(Potentilla recta) was in full bloom
Sleepy Parabagrotis moth
tapped from a cone
I tapped a full set of 50 Douglas-fir (Pseudotsuga menziesii) cones here as well as a partial set of 25 ponderosa pine (Pinus ponderosa) cones. The Doug-fir cones were easily accessible roadside cones. The ponderosa cones required a little hill scrambling and then burrowing under a redstem ceanothus (Ceanothus sanguineus) that encircled my cone source. I collected 7 juvenile spiders from the Doug-fir cones and 3 juveniles from the ponderosa cones. The families represented were typical for this microhabitat: Amaurobiidae, Anyphaenidae, Gnaphosidae, Linyphiidae, Pimoidae and Thomisidae.

Ruby Creek

Looking uphill to source of
roadside ponderosa cones
The lush surroundings that the closed
road cones rolled into
We made our second stop where the forest road crosses a tributary of Ruby Creek. I tapped two full sets of 50 ponderosa cones nearby, both at elevations of about 2,660 feet. Both sets of cones had accumulated where steep hills met a roadside ditch. I found one set along the main forest road, where it was fully exposed to the sun. The other set was along a shady, closed forest road that was quickly being overtaken by bigleaf maple (Acer macrophyllum).

Rod the Rock Chucker making the
road surface safe for my city car
I collected 2 juvenile spiders from the "sunny" set and 6 from the "shady" set. The families represented in these samples (Agelenidae, Araneidae, Clubionidae, Linyphiidae, and Lycosidae) were again typical, for the most part. I rarely tap araneids from fallen cones, but it has happened before. The absence of theridiids from all of the day's samples was unusual since the family Theridiidae accounts for 23% of spiders tapped from fallen cones in eastern Washington. However, like the odd araneid in a cone tapping sample, an absence of theridiids has happened before.

A Lorquin's Admiral (Limenitis lorquini) sipping salts from Rod's pack.