One of the life’s small ironies is contained within the form of a medium sized ant called the Yellow Ant.  These critters are better known as Citronella Ants because they emit a very strong sweet odor which smells like, you guessed it, citronella.  I think that ironic because citronella oil has been a major insect repellent agent for many decades.  The actual chemical scent emitting from the ants is different from the scented oil that we use in our backyard mosquito repellent candles (which comes from a type of grass), but I still find it odd that we use a known insect smell to repel insects.   

 The reason I bring this topic up is that I witnessed a swarming flight of citronella ants the other day.  The planter bed next to my front door was crawling with hundreds of ants and the air was charged with that familiar scent.  Mixed in among the “regular” pumpkin orange workers were winged ants nearly twice their size (see here).  There’s a good chance that you’ll witness a few of these ant “coming out parties” yet this fall, and knowing what they are will ease your mind.  Too often we assume such swarms to be termites or carpenter ants. In short, the sweet smell alone should immediately set you at ease and noting their color and behavior should keep you there.  Citronella ants are harmless colonial farmers that do not impact our daily life in any negative way. 

  For most of the year, these ants live in a subterranean world of darkness – never willingly venturing up into our space.  Down in their tunnel system they quietly farm herds of plant aphids attached to plant roots. The ants protect the aphids from predators and the aphids return the favor with the gift of honeydew droplets– a sugary product issued out the south end of an aphid heading north. Occasionally the farmers eat a few of their charges every now and then, but for the most part it is a very domestic and amicable relationship.   

  After a few months of good husbandry combined with the efforts a productive queen and her attendant workers, the colony thrives.  Eventually things begin to get a bit congested.  During such times a chemical signal sets off the production of special ants called reproductives that are meant to leave the home colony and establish new ones elsewhere. Reproductives consist of fertile females (new queens) and newly minted males which are eager to mate with them.  The hitch is that all this hanky panky has to be done far from the colony (so the grubs don’t have to watch) so these sexually active ants are endowed with wings.   

  The emergence of a swarm of winged ants is a phenomenon known as a nuptial flight.  Swarming usually takes place in the cool of the afternoon or morning.  During the height of the emergence, these earth dwelling ants come to the surface for a brief time and the ground above the colony resembles a madding crowd. Workers mingle with their winged mating core and boil around as if giving their colonists a grand send off – possibly saying things like “good luck in the New World” or “don’t forget to write.” The new queens take flight and the males follow them off into the undiscovered country (see here).   

  The flight that I witnessed peaked at 5:30 pm and was complete by 5:45 pm.  By 6:00 pm not a single living worker remained above ground.  The aphid herders returned to their old pastures. A lucky spider was finishing up a silk wrapping job on the body of an unlucky winged male who should have zigged when he zagged, but all the other winged ants have cleared the scene. Perhaps one or two of the departed couples will successfully mate and start a new Citronella colony.  The first thing they will do is shed their wings and return to the sweet earth from which they came.