Exploitation of a porch lamp by a jumping spider.

Male jumping spider (Platycryptus undatus).
(Photo by Judy Gallagher Flickr CC BY 2.0 Title: Jumping Spider - Platycryptus undatus, Leesylvania State Park, Woodbridge, Virginia.)

Male jumping spider (Platycryptus undatus).
(Photo by Thomas Shahan Flickr CC BY-NC-ND 2.0. Title: Adult Male Playcryptus undatus Jumping Spider [with Video!])

Jumping spiders ordinarily use their big, forward-facing eyes to hunt in bright sunlight, without the use of webs. They stalk and pounce on prey. At porch lamps at night on Cape Cod, Massachusetts, the jumping spider Platycryptus undatus used artificial light to hunt prey attracted to the light. The prey included leafhoppers, flies, lacewings, and moths. The spiders ignored beetles, whose hard outer covering may have deterred them. Potential prey at the porch lamp arrived so frequently that it would distract a spider stalking prey. This “paradox of choice” temporarily prevented the spider from completing attacks.

I do not know what aroused this jumping spider and induced it to begin hunting at night. Did the artificial light stimulate it? Did the light reset its biological clocks? Did prey drawn to the porch lamp trigger its activity?

In Philadelphia, bridge spiders (Larinioides sclopetarius) build webs at municipal lamps and snare insects attracted to the light.

Spiders at lamps illustrate how artificial lighting at night can benefit some species at the expense of others.

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View my published research on jumping spiders at porch lamps.