Wednesday, June 18, 2014

Bold Jumping Spider

Bold jumping spider, dorsal view - REK
Ventral view
I felt a little like Little Miss Muffet when I came out for my morning coffee and saw the spider descending from the ceiling beam toward our sink.  It nestled in to a ziplock bag for photographs.  I was too busy to start a long search and our copy of Spiders and their Kin reference was lost again.  It is always missing and we suspect it is taken under the furniture for bedtime reading by our resident wolf spider.

I sent a query to Bugguide.net and got back this response within a few hours, identifying it as a bold jumping spider, Phidippus audax.  This is a common spider in our area, and as you can better see from the photographs by Sam Martin, it is a beauty.

Bold jumping spider - Sam Martin

P. audax has distinctive white markings on the top and bottom of the abdomen as well as white stripes along the bottom of its legs.  These are more orange in younger spiders as you can see on ours.  P. audax belongs to the genera Phidippus which are larger than most other jumpers and have iridescent chelicerae, seen here as a bright metallic green.

Wikipedia has this to say about jumping spiders in general.
"The jumping spider family (Salticidae) contains more than 500 described genera and about 5,000 described species, making it the largest family of spiders with about 13% of all species. Jumping spiders have some of the best vision among arthropods and use it in courtship, hunting, and navigation. Although they normally move unobtrusively and fairly slowly, most species are capable of very agile jumps, notably when hunting, but sometimes in response to sudden threats."
Bold jumping spider - Sam Martin
P. audax is a daytime hunter, using its acute vision to track and stalk its victim.  It then pounces and neutralizes the creature with venom delivered by its jaws.   When it jumps it releases a silk safety thread behind it, a spider version of a bungee cord.  If it misses the target, this ensures that it can get back home.

Red admiral for lunch at the Butterfly House - Chris Barnhart
Their diet is carnivorous, encompassing a wide variety of species.  Many of these are pest species, such as plant bugs, weevils, and bolls that eat cotton.  Like most predators, they don't pay attention to human sensitivity when eating more charismatic species.  Above is a bold jumper munching on a red admiral, a sin in the Butterfly House that likely got it squashed.

On rare occasion, a bold jumping spider may bite a human if threatened by grabbing it or pressing on it.  These bites may create a pustule but don't cause any serious consequences.  That said, you might find this Youtube video outside your comfort range if you have a touch of arachnophobia.
When bold jumping spiders jump, they release a line of webbing for security. This ensures that if a leap fails, there is a safety line that will catch the spider before it falls
When bold jumping spiders jump, they release a line of webbing for security. This ensures that if a leap fails, there is a safety line that will catch the spider before it falls
When bold jumping spiders jump, they release a line of webbing for security. This ensures that if a leap fails, there is a safety line that will catch the spider before it falls

Animaldiversity.ummz.umich.edu has extensive information on P. Audax.

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