Messor pergandei


Messor pergandei is a common ant in the Sonoran Desert around Phoenix, Arizona. It comes in a range of sizes, as illustrated in the photo to the right. The larger size is about 8-9 mm in length, while the smallest are around 4 mm. Sometimes nests will seemingly be comprised only of smaller sized ants, but most nests seem to contain several size classes.
Messor pergandei videos (Apple QuickTime Format)
  • Video 1 (608 KB) - These ants can be very sensitive to disturbances. In this video, I stopped holding my breath and can see that the M. pergandei get mildly upset about it.
  • Video 2 (864 KB) - A worker removes a dead worker from the nest
  • Video 3 (1.5 MB) - Nice closeup as a worker walks by the camera
  • Video 4 (920 KB) - A really nice closeup as a worker pirouettes in front of the camera
Messor pergandei is a jet black ant, in some lights so shiny that it appears to be metallic. Like Aphaenogaster cockerelli, Messor pergandei has a pair of spines curving off of her thorax. Unlike Aphaenogaster, the spines are usually straight. Messor pergandei does not have a functional stinger.
The photo on the far right shows Messor pergandei's psammaphore - a collection of long, curving hairs beneath the mandbibles. Psammaphores are a fairly common trait among desert ants. Many authors speculate that the psammaphores help the ants to carry larger loads of fine particled soil. The photo on the near right shows off the ant's carina - the raised ridges around the base of the antenna. I read somewhere that the purpose of the carina is to give the ant a protected area into which to pull the antenna, especially when fighting other ants. Ants in the subfamily Myrmicinae, to which Messor pergandei belongs, tend to have well developed frontal carina.

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