Bronze Jumper

Salticidae—Jumping Spiders

(Eris militaris)

This spider is found throughout most of the continental United States and Canada. Only a handful of salticids have such an extensive geographical range.

Description

Eris militaris in retreat. Photo by Lynette Elliott, BugGuide.net, photo# 457512

The males have a dark cephalothorax with white bands along the sides. The chelicerae are relatively long and extend forward from the front. The abdomen is lighter in color than the cephalothorax and it too has white bands that run laterally. Females have a lighter cephalothorax than the males and a slightly darker abdomen, but they do not have the lateral white bands. The abdomen has a short white band near the cephalothorax and a series of elongated dorsal white spots. Females are 6 to 8 millimeters long, while males are 4.7 to 6.7 millimeters.

Life History/Behavior

Eris militaris is a jumping spider that can be seen around many homes and in fields and woods, though it is often overlooked due to its small size and bronze-brown color. Found in both rural and suburban locations, it is most often seen in the fall crawling on the exterior or interior of buildings. Bronze jumpers will sometimes aggregate in the fall to overwinter under the bark of dead trees.

Medical Importance

This species is not medically important. (Note: The original author of this publication had personal experience in this regard. While attempting to get the spider to look at the camera by using his index finger to get the spider's attention, the male pounced upon the fingertip, bit it, and hopped off. The pain was immediate and surprisingly distracting. After only 15 seconds the pain was gone and no other symptoms developed.)

References

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