Invasive Animals - Fiery Intruders

‘Does anyone have something for fire ants???’ they ask in the neighborhood WhatsApp group. ‘It stings’, cries the little kid. Pets will also cry out in their suffering.
It’s small, but it’s here to stay and is classified as one of the 100 most damaging invasive species in the world.
At the end of the 1990s a ship reached the country’s south with a shipment of wooden planks carrying a hidden traveller, the fire ant. Or perhaps it was backpackers who brought it from Brazil. There are different versions to the story, but it’s certain that under our noses and feet it began to spread and multiply. By the time it was discovered there were already masses of particularly annoying ants in different locations around the country.

Who are you, fire ant?

It’s tiny, only 1.5-4.5 cm in length, red, comes from South America, knows how to float and swim, eats everything, is industrious and spreads at a rate of about 70 m per year.

It’s so tiny, who does it hurt?

The extent of its damage is inversely correlated to its physical size. Being omnivorous, it is dangerous and harmful to a wide range of animals, it doesn’t leave food behind for others and can prey on grasshoppers and spiders; even chicks can be eaten by groups of these small, venomous ants.

Ants are social organisms. Local species tend to fight with each other over resources, but the invasive fire ants do not fight each other; rather they work together against everyone around them.

This fact, which characterises invasive species, significantly favours them to the detriment of local ant species.
Wherever there are fire ants, within one decade there will be no other species of ants, and barely any other arthropods such as spiders, beetles or grasshoppers! It directly harms others and their food. The little fire ants have an enormous impact on biodiversity. And what about humans? It stings and hurts, causes tremendous economic damage to agriculture and tourism, and can also cause irreversible damage to pets, including blindness or death, in the case of small pets such as hamsters.

The little fire ants have an enormous impact on biodiversity. And what about humans? It stings and hurts, causes tremendous economic damage to agriculture and tourism,

How do they keep spreading?

The biggest sources of dispersal of fire ants are nurseries, where they get into plants, compost or soil and move from place to place, settlement to settlement, and reproduce the way they know best.

Here at Ramat Hanadiv

The fire ant was discovered in 2017 (mainly in the irrigated parts of the Memorial Gardens), and localised treatment was performed using granular preparations. About a year later, during monitoring performed by Ramat Hanadiv’s gardening and research staff, in collaboration with the Entomology Lab for Applied Ecology at Tel Aviv University (led by Itai Ranen) most of the garden area was found to be infested. Similarly, the abundance and richness of other arthropods that populate the gardens was significantly lower in locations with high infestation of the fire ant compared to locations with low infestation or no ants at al.

After examining different alternatives for treating the fire ant and its damaging impacts, it was decided to treat it. To test the effectiveness of spraying and the possibility of undesired effects on the arthropod community in the gardens, a series of samples was taken at different periods of time from the treatment date and during subsequent months.

After two years and seven rounds of sampling, accompanied by monitoring of the recovery of the soil-dwelling arthropod community in the gardens (using special traps) as well as the bees and butterflies, the fire ant population shrank significantly but was not completely eradicated. Furthermore, the treatment did not cause any damage to the arthropod community.

Wherever there are fire ants, within one decade there will be no other species of ants, and barely any other arthropods such as spiders, beetles or grasshoppers!

In your homes

If you feel or encounter fire ants at home or in the garden you can check the extent of the damage. Fire ants are strongly attracted to peanut butter. Take an ice lolly stick, spread on some peanut butter, and place it in a strategic location. Check it after about two hours; if it’s completely covered in ants you have a problem that requires professional treatment.

How do we treat the ants?

At home, when infestation is not high, you can use granular or gel preparations available for purchase in many shops. These preparations act as bait that is designed to reach the queen ant. It is important to only use preparations that are suitable for use on the little fire ant. The preparation should be used according to the guidelines on the label. Do not make any changes to the applied preparation. Application of granular preparation will be done only in locations that are out of reach of children and/or pets. To ensure effective treatment, granular preparations should be applied in dry conditions, that is, two or three days after watering and two or three days before watering an irrigated garden. The recommended treatment time is immediately following the appearance of the first ants; this usually takes place from April. The most successful monitoring and treatment time is late morning and afternoon.

How to prevent the ants from coming?

The next time you visit a nursery, ask the staff how they treat or prevent entry of the fire ant. In addition, check the seedling by taking it out of the pot (this is an opportunity to check the state of the roots and quality of the seedling); a thorough examination together with satisfactory answers from the staff regarding treatment of the nursery against the fire ant will ensure that you bring home a happy pot plant and not an annoying ant.

The biggest sources of dispersal of fire ants are nurseries, where they get into plants, compost or soil and move from place to place, settlement to settlement, and reproduce the way they know best.