Ants in the Saddle - Part 2

Jean Parker posted several picture of a Dryad's saddle mushroom in her tree, shown in the last blog.  This and a few ants crawling it have made a story that requires two blogs for the telling.  Jean goes on to say, "I look closely and see ants busy taking pieces of it UP the tree. Probably penthouse spoils. They came down from the rotted knot in tree then went to right then up up and far away.   Wow, nature never ceases to amaze."

 

Most amazing is the little ants measuring 4-5mm are able to work as a coordinated team of 20+ to chew a piece of the fungus from the edge and then haul it up the tree!  It reminds us of the rubber tree in the song High Hopes.

I sent this photograph to James Trager who responded:

"This ant - Aphaenogaster tennesseensis - is omnivorous, though perhaps more predatory-carnivorous than most in its genus. I commonly see them on a variety of recently formed fungal fruiting bodies, and presume they are taking home bits to feed their larvae. I have not actually seen the larvae chewing on mushroom bits given to them by their older sisters, but I'll just bet if you could peer into the brood chamber after the adults bring this material home, that is what you would see."

To illustrate AT's carnivorous side, James sent along a photograph from the St. Louis area of the same species a few days later.  These ants were hauling in a millipede for supper.  This is the underside, a white and no doubt juicy teneral, having just emerged from its molted skin.  Ordinarily it would toughen and develop color over the next few days but this one may not live that long.  Meanwhile some were carrrying a piece of bark up the tree as seen in Jean's video.

Meanwhile, back at the fungus,  Antwiki says A. tennesseensis, "Nests may be in rotting stumps or logs, in standing dead trees, and in dead portions of live trees (Smith 1965). Mature colonies have several hundred to several thousand individuals (Smith 1965). The latter estimate would be unusually high for a species of eastern Aphaenogaster. Foraging is usually on the ground, where the workers collect small arthropods" 

Diving deeper, we hit pay dirt.   Food-webs posted research showing this is a common finding in Aphaenogster sp.

"Previous accounts of fungivory in ants outside these fungal-feeding specialists have been questioned due to whether or not ants consume fungal tissue or prey on mycophagous insect larvae present in or on mushrooms. Here we show that ants in the widespread genus Aphaenogaster recruit to mushroom baits in the field regardless of whether or not mushrooms contained insects upon which ants might prey. When dye-stained mushrooms were provided to colonies in the lab, ants fed on mushroom tissue and dye was visible throughout their digestive tract."

To quote our fellow naturalist Jean, "nature never ceases to amaze."