For first time, ‘little fire ants’ discovered to endanger lives

Doctors in Sheba Medical Center are the first to discover that the invasive species is not only a garden pest, but fire ant bites can also endanger lives.

 Red ants - also known as fire ants or solenopsis are stinging ants. (photo credit: Wikimedia Commons)
Red ants - also known as fire ants or solenopsis are stinging ants.
(photo credit: Wikimedia Commons)

Doctors in Sheba Medical Center at Tel Hashomer have discovered that the “little fire ant” – an invasive species – is not only a garden pest, but fire ant bites can also endanger lives. Their revelation appears in the latest (April 2022) issue of Harefuah, the Hebrew language journal of the Israel Medical Association. Only yesterday, a section the State Comptroller’s report mentioned that Israeli ministries and non-governmental organizations have done little to fight invasive mammals, birds, insects, plants and microorganisms that infiltrated the country, causing harm to native species. But the report does not mention the fact that the orange/red-colored ants endanger life or how and from where they reached Israel.

The Harefuah article was written by Dr. Mona Kidon (director of the pediatric allergy clinic at Sheba’s Safra Children’s Hospital), Dr. Yoram Klein (director of Sheba’s trauma unit); and Tal Weinberg (of Sheba’s oncology service).

The rare case of the 15-year-old youth 

Until this article, they wrote, there have been no reports of life-threatening effects from little fire ant bites. However, the ants claimed a victim in a 15-year-old Ramat Gan youth who survived due to proper treatment.

During the last two years, he had four events of urticaria (hives), mucosal tissue congestion in his mouth and nose, shortness of breath, swelling of his lips, ears and around his eyes. All these events occurred during the summer when he spent time in private gardens and public parks and felt a bite that caused itching but not pain.

After all these events, he was examined within half an hour at Sheba’s pediatric emergency room and given corticosteroids, antihistamines and adrenaline and was under medical supervision. At first, it was thought he was reacting to food to which he might be allergic, but tests showed this was not the case. If he had not been treated, the doctors said, he would have gone into anaphylactic shock, in which blood pressure drops suddenly and the airways narrow, blocking breathing.

Sheba Medical Center at Tel Hashomer  (credit: SHEBA MEDICAL CENTER)
Sheba Medical Center at Tel Hashomer (credit: SHEBA MEDICAL CENTER)

Fire ant bites - What do fire ants love to eat? 

Staff were sent to the parks and gardens where he had spent time and collected scores of little fire ants, attracting them with Bamba peanut-flavored corn snacks.

He was found to be very allergic to the poison released by the insects; when three people were tested – his father, a nurse and the head of the allergy clinic, none had a reaction.

The authors noted that the dangerous, invasive insect (Wasmannia auropunctata of the genus Solenopsis) has spread throughout Israel and to many parts of the world and that action must be taken by the authorities to monitor, map, and eradicate the ants, then to develop effective immunotherapy from the poison.

What is a fire ant, and where does it come from?

The ant originated many years ago in Central and South America, from where it spread to Florida, Africa, Australia, Pacific islands, and to many other parts of the world. Now prevalent in Israel, the ant’s proliferation is attributed to trade in wood in which nests of the ants are found. The insect spread here by means of wood chips for mulching, logs for heating, wood and plant cuttings and earth, especially in plant nurseries.

Although they are usually found outdoors, they may enter homes in the summer in search of food, as well as moist and cool places such as baths, sinks and closets. The little fire ant is orange-red in color and about one millimeter in size, though the queen ant can grow to 2mm.

It stings humans during all hours of the day, and biting occurs mostly when the ants are trapped between a person’s skin and clothes.

The little fire ant can also harm pets, livestock, wildlife, crops, garden plants, and biodiversity. If they sting a dog or cat in the eye, the pet could be blinded.  

Prof. Abraham Hefetz, chemical ecologist and evolutionary biologist at the Wise Faculty of Life Sciences at Tel Aviv University who wrote a paper on the insect, first discovered the ants at Kibbutz Afikim in the Jordan Valley in 2005 after children jumped out of the swimming pool in tears from painful stings.

“No one really knows when the invasion actually started. Back then, one of my students, who was researching the impacts of invasive ants, found a species she didn’t identify during one of her collection trips to the Sea of Galilee,” he said a few years ago. The original ants are thought to have arrived at the kibbutz’s woodworking factory in a wood shipment from Brazil.

“It is unclear how the ant got here all the way from Brazil, but there is a very good chance that young Israeli backpackers unwittingly brought the ant back home with them. Since South America is a popular backpacking destination for young Israelis after completing their army service, this could be a very tangible possibility,” suggested Hefetz.

“The little fire ant has a very peculiar reproductive system. Every queen is the clone of their mother, while all the males are a clone of their fathers.”

The authorities did little or nothing about the invasive species, causing it to reach at least 300 communities around Israel. The comptroller’s report said that from 2030, if not eradicated, the ants would cause about NIS 1.2 billion shekels worth of damage annually.