Ants and Dragonflies

 

The year is full of seasonal events.  Some I like and some I don’t.  As I was heading home yesterday evening, the road through our nearest town was closed in preparation for the annual fall street fair.  That’s one of those events I don’t like.  When I finally pulled into my driveway, I saw a large dragonfly swarm circling the Prairie Garden.  I always enjoy the fall swarms of dragonflies and this one was partly created by another of my favorite events.  Ants were swarming.

Ants taking off on their mating flight remind me of chumming the water for sharks.  Dragonflies come from all directions to feed on the ants.  This is usually an evening event and the lowering sun lights up both ants and dragonflies.  Unfortunately, it’s almost impossible for me to capture a photo that comes close to illustrating the beauty of the interaction between these two insects.  Nobody would guess that this photo contained a couple dozen flying ants and four dragonflies.

Occasionally I’ll capture an image that is recognizable as a dragonfly.  They all appeared to be Common Green Darners.

Other photos seem more suited to proving the existence of pixies or tiny x-winged fighters cruising above the fields of Blue Jay Barrens.

The dragonflies seemed to be targeting the large queen ants.  The queen’s flight was rather slow and there was a good bet that a dragonfly would nab her before she topped an altitude of 12 feet.  I think I just caught the tail end of the swarming event.  I probably would have been home in time to see the entire swarm if I hadn't had to detour around town.  During the peek of the swarm there would have been far too many ants in the air for the dragonflies to have caused much damage.  Those last few ants would have been trying to survive a sky full of predators.

The ants attempt to reach a high point, such as the tip of a blade of grass, before launching into the air.  This queen kept running up the grass blade and plummeting from the tip back down to the ground.  That’s probably why she’s one of the last to take to the air.  Maybe it’s best for her to be eaten, so she doesn’t pass on those bad swarming traits.

The workers and winged males were very small.  I had to crawl with my face almost to the ground in order to find them.  During the search, the neighbors drove past the house.  They just waved.  I guess my behavior no longer strikes them as being odd.

Amidst all of the workers was one that carried an ant cocoon in its jaws.  I guess being late hatching doesn’t excuse you from swarming.

Ant Swarm

Everybody likes a good swarm and ants are master swarmers.  I believe this species is Acanthomyops interjectus, AKA Larger Yellow Ant, one of several that produces a lemony fragrance.  They nest behind the brick wall of our cellar and release thousands of winged queens around this time every year.  Usually the swarm takes wing in the basement, but this year’s warm weather may have altered their pattern to an outside departure. 

Workers are a yellow or copper color.  Other similar species share this appearance and identification comes down to things such as eye size, hair placement and body size.  I hope I was looking at the right things as I worked my way through the ant key.

Winged females stage beneath rocks and other cover or in shallow subterranean chambers.  When it comes time to leave the nest, the workers rapidly open passageways and shoo the fliers out of the nest.

The workers provide some protection during the exodus, but I think their primary function if to persuade the unfertilized Queens to get out and fly.  Workers are quite apt to give a laggard Queen a little bite of encouragement.

Once the Queens get moving, the action proceeds at a frantic pace.  The goal is to become airborne, mate and settle down somewhere to start a new colony.

The way they climb over one another, it’s a wonder any of them ever take off.  The literature identifies late summer as the breeding time for these ants.  Early spring swarms are described, but no winged males are reported.  I know that in all the years I’ve been watching this colony, I’ve never seen a spring time male.  So I’m puzzled as to what happens to all of these departing Queens if there are no males out there waiting.

After successfully mating, the Queen will shed her wings.  With no males in the vicinity, there could be no mating, but when the swarming activity began to reach its end, I noticed several wingless queens.  Most were wandering the ground in an apparent search for a secluded spot.  A few stuck with their winged colony members.  These may have disappeared back into the protective chambers with the Queens that didn’t make it into the air.  This swarm is in its fourth day with activity beginning about a half hour before sundown and ending about 20 minutes later.  The swarm suddenly erupts from the ground and at some silent signal, all the ants that haven’t flown are suddenly sucked back into their tunnels.

Not all of the hopeful Queens survive the flight.  Water is a death trap.  I frequently find winged Queen ants floating in the Water Garden.  When the flight originates only a few feet away, the number of floating ants really adds up.

The bounty isn’t wasted.  Just about everything likes to eat Queen ants.  Frogs cleaned up most of the swimming ants.  Water Striders also took advantage of the glut of food.  Apparently mating doesn’t interfere with eating, at least for the female.