Fire Ants (solenopsis invicta)

Painful stings leave an impression. Everyone who has ever been stung has a story to tell.  Some of the stories of painful stings include common characters, such as honey bees (Apis melifera).  Being stung by a bee is fairly common, but unless you are allergic to them, your story is comparable to a common children’s tale: most people have read it, but can only vaguely remember how the story goes.  Another fairly common insect known to ruin the picnic is the fire ant (Solenopsis invicta).  I would guess that if the number of books sold describes the number of people stung, than the fire ant is a number-one best seller.  I once asked students in my environmental science class to raise their hands if they had ever experienced the pain and blistering associated with a fire ant sting.  All but one raised their hand.  I can only assume the one not raising a hand was new to Texas or the Southern United States.  Unlike bees, however, most people had better recall of fire ant stings, probably because if you been stung once, you have likely been stung multiple times – fire ants have a nasty strategy of waiting for a signal and then all stinging all at once.

Unidentified pseudomyrmex ant species  living in hollow spaces of this tree.

There are some insect stings, however, that if you have ever experienced it, you will never forget it.  I was recently stung by a species of pseudomyrmex ant, which made the fire ant sting seem almost pleasant.  These ants, found in the Amazon rainforest, only live in one particular species of tree.  They have a symbiotic relationship, meaning they both benefit from each other.  The tree exudes nectar that is nutritious and delicious, at least to the ants, and the ants protect the tree by stinging any animal, or plant, that gets too close.  The ants live in hollow areas of the tree and when disturbed, as for example when I knocked knuckles on the tree, they come running out.  They are fast, so it took no time at all for one to climb between my second and third finger and let me know how it felt about me being around.   The sting was painful, like someone had shoved a sewing needle between my fingers – all the way to the eye of the needle.  On the positive side, the pain did not last as long as the pain of the fire ant sting and did not produce any noticeable welt, as the fire ant sting does.

Tarantula hawk  wasp climbing on a chair at the Southwest Research Station, Portal, Arizona.

Another painful sting you are not likely forget, and really do not want to experience, is that of the tarantula hawk wasp (Pepsis sp.).  These very large wasps sting to immobilize, but not kill, tarantulas.  After immobilizing the tarantula, a female wasp will stuff the unlucky fellow into a hole and lay eggs on it.  When then eggs hatch, the larvae  begin feasting on the still living  tarantula – a tale much more horrifying than any Stephen King novel.  These wasps don’t usually sting humans, except for those  prone to antagonize them.  There is a YouTube video “Stung by a Tarantula Hawk”, where Coyote Peterson intentionally goads the wasp the sting him on the arm.  I won’t describe it here.  The video has more impact if you see if for yourself.

A subjective index was developed to compare the painful stings associated with various hymenopteran insects (sawflies, wasps, bees and ants).   Named after the person who invented it, the Schmidt pain index rates painful stings from one to four, with four being the most painful.   I don’t know if Dr. Schmidt intended it to be funny, but for each sting rating, there is also a rather humorous description.

Fire ants only punch in at a low 1.2: “sharp, sudden, mildly alarming. Like walking across a shag carpet and reaching for the light switch.”

The honey bee gets a 2.0:“Hot and smoky, almost irreverent. Imagine WC Fields extinguishing a cigar on your tongue”

Western honey bee is one of the most important insect pollinators.

 

 

 

 

 

The red harvester ant gets a 3.0:“Bold and unrelenting. Somebody is using a drill to excavate your ingrown toenail.”

Harvester ants foraging.

 

 

 

 

 

 

The tarantula wasps gets a 4.0:“Blinding, fierce, shockingly electric. A running hair drier has been dropped into your bubble bath (if you get stung by one you might as well lie down and scream).”

Dr. Schmidt, who has a Ph.D. in entomology, received an Ig Noble Prize in 2015 for his long and detailed preparation of the Schmitt pain index.  The prize, awarded by Annals of Improbable Research, is given for: “research that makes people laugh and then think”.

bullet ant

One more insect, that I have not yet mentioned, busts through the top of the pain index, weighing in at an astounding four plus.  The bullet ant.  This ant’s sting is described as:  

“Pure, intense, brilliant pain. Like fire-walking over flaming charcoal with a 3-inch rusty nail in your heel.”

 

 

Bullet ant protecting a cocoon. Some ants only have pupae, but the bullet ant young use spin cocoons to protect developing young ants.

Bullet ants range from Central America to South America.  I had the opportunity to photograph the bullet ant in the rainforests of both Costa Rica and Peru.  The ants are large and can see very well – they will actually track your movement.  In Peru, I witnessed the ants sitting, individually on leaves, holding eggs in their mandibles.  Every leaf on the lower level of a tree was occupied, something I had never seen them do before, and am still not sure why.  I did not get stung, but needless to say, I was very careful to check every piece of clothing I had warn for any stragglers.

 

Read more at:http://scienceblogs.com/retrospectacle/2007/05/16/schmidt-pain-index-which-sting/

Schmidt pain index: http://www.wikiwand.com/en/Schmidt_sting_pain_index

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