Friday, May 27, 2011

Some Small Spiders

Relatively small, compared to some heavyweights such as the Dark Fishing Spider.

This is an Elegant Crab Spider (Xysticus elegans). Not uncommon, but often overlooked due to their cryptic coloration, small size – this one is about 5 mm long, and their habit of staying low and living near the ground.

As often happens in nature, a predator has itself become prey. This female Elegant Crab Spider has captured a predacious Carabid beetle.

Robber flies are fearsome hunters in their own right but this one has been captured by a Jumping Spider. Despite the distinctive markings on the abdomen I haven't been able to get a better I.D. on this spider than possibly Phidippus clarus.

This unknown spider at BugGuide.Net looks the same but there's no consensus as to species. To make life a little more complicated ... Phidippus clarus can have different color forms, and it's also possible that my photos are of an immature specimen, which can look very different from an adult.

There seem to be dozens of different kinds of jumping spiders lurking on the vegetation. I don't know what this robust little female is either.

Insects aren't the only arthropods that have fatal encounters with spiders, sometimes it's other spiders. The large pale spider is about 10 mm long. It's a Slender Crab Spider (Tibellus sp.), and this time a Jumping Spider's turn to play the role of the hunted.

A Flower Crab Spider (Misumena vatia) lurks on vetch.

The spider's patience has paid off. Though larger and possessing a stinger the bumblebee never had a chance, as the venom of these crab spiders is specifically toxic to bees.

Excluding its legs this Long-jawed Orb Weaver (Tetragnatha sp.) is about 15 mm long and can easily mistaken for a grass seed when at rest.

This mug shot is about the best detail possible with a subject so small (good lighting really helps!). The appellation "long jawed" certainly fits. Note what looks like globules on the ends of stalks: this spider is a male and the balls are sperm packets on the ends of its pedipalps. (The pedipalps are the two "feelers" at the front of a spider – they are not true legs).

Most orb weavers spin a new web daily, abandoning the old one. Almost invisible, these webs often entangle unwary victims such as this Four-spotted Skimmer.

The following three images were acquired indoors under poor lighting so they can't do justice to the eye-catching color scheme of this female cobweb spider. It's about 5 mm long, and the abdomen is black with silver markings. This is (probably) a Triangulate Cobweb Spider (Steatoda triangulosa). A welcome guest in many homes, as it is known to prey on fire ants, ticks, and spiders whose bite is harmful to humans such as the Hobo Spider and the Brown Recluse. With the exception of ticks none of these other arthropods are extant in this area, so a wasp moth will do for lunch ...

As I was taking photos of this Wolf Spider (Lycosa sp?) it seemed like something looked wrong with its abdomen. Zooming in on the image later showed what was amiss ... this is a mother spider with her young hitching a ride on her back. They will stay with her for a few weeks until they are old enough to fend for themselves. Small spiders indeed ...