Tuesday, September 29, 2015

Orchard Orbweaver



Tonya Smith found this little 6mm spider in the woodland portion of our Master Naturalist chapter's training field trip to Henning Conservation Area last Saturday.  It was on a small web stretched between several branches of a sapling three feet above the ground.  With the naked eye we could catch an almost metallic glint to the abdomen.



Under magnification the abdomen looks like a capsule, decorated with glitter and a peace symbol and then glued to the back of a spider.  In fact, it is original equipment, the standard abdomen design of the Orchard Orbweaver, Leucauge venustaLeucauge is Greek for "with a bright gleam" while venusta is Latin for beautiful, an understatement in this case.  This name was created by Charles Darwin, the only spider he named.



The female typically builds her web horizontally, close to the ground in shrubs and juvenile trees.  She hangs upside down while waiting to trap small insects, allowing her to drop down quickly if disturbed.  She produces eggs throughout the warm season, attaching the egg cases close by on leaves or twigs, home to her young until they emerge and build their own webs.  The adults die with the onset of winter while the eggs survive producing next year's spiders.

Note the eye placemen t- click to enlarge  - Arch Baker *
The color and shape were distinctive in this species but identification of some spiders requires details such as the eye placement.  In this case there are two pair of prominent eyes in the center and two pair laterally arranged vertically as seen above.

MDC Field Guide
http://www.spiders.us/species/leucauge-venusta/* License/Copyright: Used with Permission