Last week I flipped over a rock about six inches square and found this:
Okay, it doesn't look like much until you zoom in closer.
The grayish-mound is a solid mat of oval, wrinkly seeds. Apparently they had been gathered and stored by the Southern fire ants (Solenopsis xyloni) you see running around. The ants were in full defensive mode.
The seeds were both on the ground and on the underside of the rock, so there was quite a mass of them.
Seeing the seeds reminded me of an earlier time (above photograph) I had found a similar cache of seeds under a rock . At the time I didn't know what plant they were from, but now I have figured it out.
These seeds are from a type of ground spurge, Chamaesyce prostrata. Another common name is sandmat. (See post about Southern fire ants and sandmat).
The University of Arizona has an illustration of the plant in their older weed manual under the name Groundfig Spurge, Euphorbia prostrata. See the seed labeled "d" in the illustration?
A quick search of the internet revealed the UC IPM website states "Weed seeds, particularly spurge, may attract the ants away from the bait..." This statement is referring to Southern fire ants in almond groves.
Seems like there might be something worth investigating going on here.
Have you ever seen Southern fire ants with seed caches? What kinds of seeds did you find in them?
From the archives:
Often when we put out watermelon for the birds, the fire ants take their share.
The ants are still active here, but I haven't had much to report. In an effort to get back in the swing of things, I will be posting some short notes.
Do you know what this is? I tipped over a rock near a Southern fire ant nest and found this cache of tiny seeds. It is easy to forget that fire ants also harvest seeds.
I should have picked up a couple of the seeds to try to sprout them. It wasn't obvious where they came from, as there weren't any plants nearby.
Have you ever found seed caches in fire ant nests?
Did you know that today is International Rock Flipping Day?
The idea is to go outside, flip over a few rocks, and record what you see. The resulting posts will be published at Wanderin' Weeta.
After looking under a couple of rocks, I posted about most of the creatures I discovered (including a very cool case-bearing larvae) at Growing With Science. Of course flipping rocks is a fabulous way to find ants (and "experience" ants in other ways, too), so let's take a look at what ants were hiding under rocks today.
The area I chose has mowed grass with a brick edging around it, as well as some rocks piled up in a drainage ditch. It isn't uncommon to see Forelius running along the edging, so it was no surprise to find a few under the rocks as well.
Southern fire ants were in full force, too.
I was surprised how much more red these show that the ones in my yard a football field-length away.
I managed to get stung while taking this photograph. (Flipping rocks does has its hazards.)
Of course, Dolichoderinae don't sting.
But they are more than willing to bite.
At least it was sitting still, so it is in focus 🙂
Did you participate in International Rock Flipping Day? What did you find?