Wednesday, July 17, 2013

Male Zygoballus sexpunctatus on Crepe Myrtle

Wikipedia reports: "Specimens have been collected from several different ecosystems, including old fields, river terrace forests, flatwoods, Florida Sand Pine scrub, Slash Pine forests, Appalachian grass balds, and rice fields. Robert and Betty Barnes reported the species as occurring in broomsedge fields throughout the southeastern Piedmont. The species is typically found in the herb stratum (among grasses and other short plants) and may be collected with a sweep net."

BugGuide reports: "All Zygoballus specimens collected by the author (jb) have been found in short, broad-leaved vegetation less than 1 ft. from the ground."

Well, the male I found climbed right up into a crepe myrtle tree, more than 1 ft from the ground. In fact, he was at or above my eye level (5 ft +) most of the time! As you can tell, I'm ecstatic to have discovered this species in our yard. Zygoballus sexpunctatus (family Dendryphantinae) is a truly beautiful jumper and I enjoyed interacting with it.

Adult males are easily recognizable by the fact that they wave their large, dark front pair of legs around all the time. They do this to appear threatening, as well as to be ready to jump onto a new object or pounce on prey. (Once he sprang onto the branch behind which I was watching him, and I ducked, thinking he had hopped onto my head!) Another menacing feature of this spider is the enlarged, obliquely oriented black chelicerae, which each have a prominent inner tooth and a long curved fang. I wouldn't want to be on the receiving end of those! The abdomen is bronze to black with a white basal band and two transverse bands, often broken up to form 6 spots (hence the species name). The bands on my specimen were not broken up, however, and he had also had a white spot on his carapace. The legs are reddish-brown, with black femora. And the cephalothorax is black and box-like in shape.

References: (Zygoballus) (Z. sexpunctatus) (3 videos of behavior) (diagnostic drawings) (great photos & drawings)

Daring Jumping Spiderlings

Note: I'm referring to these spiderlings as female by default because I'm unable to determine the sex.

1. This young Bold Jumper (Phidippus audax) was hunting inside a large bush that must have seemed enormous to her! She has white abdominal markings now, but will develop orange ones after a few molts, and then will regain the white markings in adulthood. Her "knees" are still reddish-brown, her palps are small and black with some red coloring on the top half, and her chelicerae are also small and dark, lacking the furry, iridescent green appearance of an adult. I wonder if she's an offspring of Wallis?

Calculating a jump...

2. A similar specimen, but on a somewhat less daunting plant (pokeweed). Her attempts to stab insects proved unsuccessful, owing to her tiny size. You'll notice her "face" (where the front eyes sit) has more of an iridescence than Specimen #1. The abdomen and carapace have shiny scales/hairs as well. Her palps appear to have some hairs on them. She could possibly be another offspring of Wallis.