Eris militaris (Hentz, 1845)
How to Identify Eris militaris (Hentz, 1845)
Family: SALTICIDAE Blackwall, 1841
Genus: Eris C. L. Koch, 1846
Species: Eris militaris (Hentz, 1845)
Origin of Name: Eris is the Greek goddess of discord or strife (known as Discordia in Roman mythology). The specific epithet militaris means "of a soldier, military, or martial" in Latin.
Official Common Name: bronze jumper
Can Be Confused With
Eris militaris (Hentz, 1845) can be confused with Eris flava (Peckham & Peckham, 1888). However, E. flava, though widely distributed in eastern North America, is more common in the southest and tends to prefer marshes and fields.
Males of these two species are easy to distinguish because E. flava males (right, below) have a white band between the large, forward-facing eyes and the jaws whereas E. militaris males (left, below) do not.
|Eris militaris (Hentz, 1845) male|
(image courtesy W. Maddison)
|Eris flava (Peckham & Peckham, 1888) male|
(image courtesy W. Maddison)
Females of E. militaris have a continuous white band from their small, side-facing eyes down to the edge of their carapace, but females of E. flava have a darkly colored patch between their side-facing eyes down to a thin white band that rings the lower edge of their carapace.
USA, Canada, Alaska.
Collection Map of Museum Specimens
in The Nearctic Spider Database
Edwards, G. B. 2004. Revision of the jumping spiders of the genus Phidippus (Araneae: Salticidae). Occasional Papers of the Florida State Collection of Arthropoda 11: 72-76.
Other Web Pages
Salticidae: Diagnostic Drawings Library (http://salticidae.org/salticid/diagnost/eris/milita-m.htm)
The Nearctic Spider Database (http://www.canadianarachnology.org/data/spiders/33233)
Observation: On milkweed leaf. I am not 100% sure of the identification of this species but there is a fuzzy picture if anyone would like to comment.
Observation: All of the following account took place on an old plastic lawnchair that is sitting in a small orchard at the edge of a woodlot on our farm. The chair is surrounded by mixed grasses, Meadowsweet (Spirea alba) and other vegetation. On 25/05/2007, a female E. militaris was observed perched on the back of the chair. It moved to hide behind the back slats when I moved in for a closer look and to take some photos. On 26/05/2007, I checked the chair and found a male spider wandering about on the chair. On 29/05/2007, I checked the chair and found a small silky nest spun between some kind of stick-like cocoon (presumably made by moths) on the underside of the chair. There was also a granular-coated, oval, cocoon-like structure incorporated into the nest, as well as a small, dark, barrel-shaped object. A male E. militaris could be seen hiding withing the nest. I failed to notice that there was a female, upside-down, hidden beneath a couple of the objects in the nest (this was discovered after examining the my photos a couple of days later). While photographing the nest, the male moved to the entrance opening to watch me (see photo that accompanies this report). After taking a few photos, I found another male E. militaris on a nearby apple tree. It rappelled off before I could take a photo. On 30/05/2007, I checked the chair and found an upside-down spider in the nest. I thought it must be the male and gave the nest a slight tweak to see if he was alive. The spider flipped over to reveal that it was a female spider (the one that had been hidden from view the previous day). It moved around in the nest and can be seen in one of the linked photos next to one of the granular cocoon-like objects). The female spider then rappelled to the grass beneath the chair. I set the chair back in place. Returning to check on her that evening, I found her back on the chair, but in a nearby silky refuge. On 31/05/2007, I checked the chair and now found a female in the second refuge, but also another female wandering around on the chair in the immediate area of the spider in the nest. I will continue to observe these spiders over the next while. Photos to accompany this observation may be found at the following URLS: