Saturday, August 21, 2010

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.