The First Spiders of the Year

A bit of snow and ice doesn't seem to discourage this young female Dolomedes striatus from getting off to an early start on the season. About 10 mm in length, if she survives long enough she will double her size, attaining a length of 20 mm or a bit more. The clearly defined bands on the abdomen and distinctly striped femora distinguish this Fishing Spider from its relatives.

A female Shore Spider (Pardosa milvina) was also active nearby, hunting for any insects bold or hardy enough to venture forth. The spiders were encountered along the shoreline of a marsh, the ambient temperature was a seasonable 15°C.

They haven't topped the record this tiny Long-jawed Orbweaver (Tetragnatha sp) moving around on the snow on January 13th, with the thermometer hovering around 5°C.

A Cave Orbweaver and a forgotten Fishing Spider

Probably not an uncommon spider but seldom encountered, as its name suggests the Cave Orbweaver (Meta ovalis) prefers to "hang out" near the entrances of caves or in rock piles. Of course man-made habitats such as cellars will serve just as well, and that's how this male came to be on the side of a building downtown. And quite a hardy spider this is, because the photos were taken on a windy, rainy November 11th, 2013, with the temperature hovering only a few degrees above the freezing point.

Cave Orbweavers belong to the family Tetragnathidae – commonly called Long-jawed Orb Weavers – but they lack the huge, serrated jaws and elongated bodies and legs of their nearest relatives.

At a length of about 12 mm this spider is a heavyweight for a male; in many spider species the males are considerably smaller than the females. The enlarged palps, modified to carry sperm packets, are easily seen in the following three images.

The female spider depicted in the next two photos was encountered at a marsh east of Tweed on August 32rd, 2011. It was fairly large, a good 25 mm in length, and although I was unable to acquire an image of the eye arrangement its general aspect was that of a Nursery Web Spider, family Pisauridae. However, this individual was much darker, and the relatively dull, straight abdominal stripes contrasted sharply when compared with the undulating white lines of the ubiquitous Pisaurina mira. I thought it might be P. brevipes, and the photos ended up being filed in my Pisaurina folder and forgotten ...

Over two years later – November 13th, 2013 – I stumbled across the photos while reorganizing some files and decided to upload them to BugGuide.Net for a positive ID. My guess as to family was correct, but the species – P. brevipes – was wrong. This spider is actually Dolomedes striatus, and it's the fourth species of Fishing Spider I've found in this neck of the woods.

Striped Fishing Spider (Dolomedes scriptus)

A somewhat atypical specimen, as the patterns of Striped Fishing Spiders generally don't contrast to this degree, and the dark areas of most individuals are more brown than black. This immature female had a body length of about 6 to 8 mm.

A photo of a similarly colored Striped Fishing Spider can be found at the magickcanoe.com Blog ... close encounters with Dolomedes spiders.

Ginormous Spider

Rain for the past week has made outdoor photography difficult to impossible and today when the sun finally peeked out it seemed like well past time to take a walk on the trail. About a kilometer east of town I came across a standing dead tree with the bark falling off and thought I'd peel it back some more to see what strange and weird critters might be lurking underneath, smiling and waiting to get their pictures taken. Well, I certainly got what I was looking for: I almost grabbed hold of the biggest spider I have ever encountered in my life! Despite its size it's almost invisible against the background of bark.

Based on the pattern of the eyes (zoom in on the next two images) and general appearance I think this a female Dark Fishing Spider (Dolomedes tenebrosus).

The spider was scurrying for cover so this lateral view is a bit out of focus but the photo serves to give an idea of how robust this arthropod is. It was in no way aggressive and once it got accustomed to my prescence I likely could have let it climb on my hand without fear of being bitten.

Just how large was this arachnid? The acorn cupule, the quarter (24 mm in diameter) and my thumb (the nail is 15 mm long) in the following images will give an idea of scale. With its legs extended the spider would have measured about three inches from front to back and easily spanned the palm of my hand.

Spider Snapshots

Several species of jumping spiders (family Salticidae) are extant in our area. The spider in the following four images is a female Bold Jumper (Phidippus audax), about 15 to 20 mm long. The three white (less frequently red, or orange as in this specimen) spots on the abdomen and iridescent blue-green chelicerae are typical field marks. Juveniles often sport orange spots.

Bold Jumpers come by their name honestly as they have been known to leap at photographers who have approached too closely. This spider was obviously feeling threatened by my presence.

There isn't enough detail in the next two images to determine if this is Eris flava or Eris militaris. For anyone interested here's a link to more information at BugGuide.Net. (EDIT: one year later, and lot more research ... I now believe this jumper is more likely genus Pelegrina).

I'm not sure as to the identity of the less vividly marked jumping spider in the next two images.

No collection of jumping spider images would be complete without the including photos of the ubiquitous Zebra Jumper (Salticus scenicus).

Sparking up the color scheme a bit: a female Black and Yellow Garden Spider (Argiope aurantiae) that has nabbed a paper wasp.

The following image is out of focus because the spider is shaking its web, and by no small amount, the spider was displaced by about two inches. I've observed this reaction in other orb weavers if they are approached too closely for their comfort. Is the purpose of this to make the spider a more difficult target for a potential predator?

Six-spotted Fishing Spiders (Dolomedes triton) are common along the north shore of Stoco Lake. The female in the image below is about 20 mm long. In the complex tangled web of life even large predators are not invulnerable; a smaller immature spider of this species has been captured by the Blue Black Spider Wasp (Anoplius sp.) in Life's a Beach.

As a rule Fishing Spiders are found on the shoreline or floating water plants. This is the first time I've seen one was making a web in the vegetation a few feet off the ground. The spider assumed this posture whenever I brought the camera up close.

Many species of Hymenoptera are parasites of spiders, but when I turned over a stepping stone in the garden I chanced across a scene where the tables were turned and found a Wolf Spider (Lycosa sp.) with an unlucky ant in its grasp.

Gardens host a variety of spider species; the spiders are attracted to the insects nectaring on the flowers. A Ground Crab Spider, probably Xysticus sp., assumes its characteristic ambush pose on an iris leaf.

Life's a Beach

Maybe not for everyone, certainly not for this Raft Spider or Fishing Spider (Dolomedes sp.). It isn’t dead … but it isn’t going anywhere soon either. It’s been stung and paralysed by the venom of the Blue Black Spider Wasp (Anoplius sp.). The wasp will bury the spider and lay its egg on it, the unfortunate spider thereby providing a non-perishable source of food for the wasp larva.

This is nature’s way of coping without refrigeration and many other local wasps have evolved similar practises for the survival of their own species. The Great Golden Digger Wasp preys on katydids, and the aptly named Steel Blue Cricket Hunter and Cicada Killer hunt crickets and cicadas respectively.

Fishing Spiders grow to a respectable size, a good ¾ of an inch … and that’s not including the length of the legs. This was a young spider, half an inch long at the most. Even so its weight was too much for the wasp to just pick it up and make a long distance flight; the insect was carrying its burden in short flits.

My presence startled the wasp at first and it abandoned the spider but it returned about twenty minutes later. The wasp didn’t come back unerringly in the exact location, rather, it landed periodically and slowly homed in, apparently seeking by smell.