Some Uncommon Ants In My Yard

While trying to photograph Aphaenogaster dispersing Trillium seeds I chanced upon a few unexpected surprises. The only colony I was able to find actively foraging happened to be in an old stump, a former Norway Maple we had had cut down many years ago. To set the scene properly this was in the shade of an Eastern Redbud Tree and the stump is now used as a perch for a Mason Bee box as well as a stone dish we use as a bird's bath. Naturally we flush out the water every day or so to keep the mosquito larva down and the stump has been getting soaked for many years. The result seems to be idea for a surprising amount of ant diversity.

The stump is absolutely teaming with decomposing arthropods. Here an Acorn Ant, Temnothorax curvispinosus, has found one. Small soft bodied creatures such as this, especially ones smaller than the ants themselves make excellent ant food. It's likely several colonies of Acorn Ants are also nesting within the log.

Here a Strumigenys pergandei has also caught something, I believe it's a spring tail. These ants are rarely seen because the only nest in shaded places that are "cold and damp." Cold refers to when they nest in soil, usually under a rotting log. Generally the soil will be cool to the touch, even in summer. They hunt and forage in rotting wood and leaf litter, often where decomposing insects and arthropods are abundant enough to have turned much of the dead plant matter into soil. Supposedly the yellowish structure on their waist segments, as well as the petal-like structures on their head and body are to help camouflage them from prey items.

This is an awful shot of a Proceratium silaceum but they were there too. Even more cryptic than Pyramica, they have a front facing stinger on the end of their gaster (abdomen) so they can sting prey that's in front of them, in tight closed spaces, as opposed to having to turn around. They're worth a google image search to get the idea.

It's nice knowing these uncommon ants can still be found in my yard, because this is the first time in several years that I've seen either in my yard. Now I know where to look!

Strumigenys Nuptial Flight in Day Light

Strumigenys is a diverse genus in North America with almost 50 species. Despite this diversity though, the genus is almost exclusively encountered by Myrmecologiests and those in other scientific fields that involve sifting through leaf litter and dead wood. 

They're so small that they're hardly noticeable, and they look so strange compared to other ants that most people would likely be confused that they were even looking at an ant.

For better close ups, here's a link to Ant Web's specimens, and Alex Wild's album of the genus. Notice the odd petal-like structures that cover the body. These are modified hairs which I believe are used help cloak the ants as they hunt. Some species in the genus have long mandibles similar to a Trap Jaw ant's. These are used to allow oils (and fungi?) which make the ant less noticeable while hunting.

They're primarily predators of springtails which are small, mite or termite-looking insects often found in decaying wood. Truthfully though these ants are more than happy to kill any sort of soft bodied invertebrate.

These ants require "cool" conditions in order to survive. In the wild they always nest inside the damp and decaying media within the hollow of a tree, or in a soggy log that's often well shaded and rotting. Other species are at home nesting in soil and leaf litter, but good luck finding those. Colonies do not make mounds of any kind, entrance holes are often cryptic at best, and populations tend to range around 200 individuals that could happily fit on a US. Quarter. 

Curiously I discovered these ants hold nuptial flights in the day time but under specific conditions. Here in New Jersey it's the calm before the storm as Hurricane Joaquin moves up the coast. The sky has been solid grey clouds for as far as the eye can see for a few days now, and raining has been off and on. It's been cool out too, around 55F but on the day that it was still 77F I happen to find a few alates to this genus landing on my car.

Ants being attracted to bodies of water, parking lots full of cars, and other reflective surfaces isn't anything new, but the fact that this genus flies in the day time is! Everything about their nesting habits has been cold and shaded, and it's entirely possible to accidentally kill them if they get too much sun. So I find it odd that they wouldn't hold nuptial flights at night.

Regrettable I couldn't locate a colony sending alates into the air. Their colonies are just too hard to find. But I was successful in catching a queen and male. I've no idea if she managed to mate or not (leaning towards no) and it's rare for ants to mate in captivity, especially after being collected. All the same, I'll give her a shot and see if she's able to produce any workers. If not then I'll have to store her in alcohol and eventually pin her for my collection.