An ant expert has cited “early detection” as the only real way to tackle an invasive species causing havoc for homeowners.
The fast-reproducing ants are hard to kill, as affected communities in areas from Alsace to Corsica have discovered.
“So far, no available methods have proven effective,” Olivier Blight, myrmecologist and research professor at the Institut Méditerranéen de Biodiversité et d’Ecologie Marine et Continentale, told The Connexion.
The species tapinoma magnum is native to the southern Mediterranean but has been found in environments across the country. The insects are small and black and have been reported to smell like “rancid butter” when crushed.
“This species demonstrates extraordinary adaptive capacities,” said Professor Blight.
“In one region, it can establish colonies in vegetated dunes of the Mediterranean, in habitats that are hot and dry in summer, but it can also be found at 650m of altitude where there is snow in winter.”
The ants have affected both agricultural areas – such as orchards and vegetable farming in Corsica – and more urban areas.
“People have become so desperate due to the presence of the species that they consider moving,” said Professor Blight.
Ad
The ants are thought to have entered France via garden centres on plants from the southern Mediterranean. They form large colonies that can have several queens. This means that unlike other types of ants in which colonies will attack each other, naturally regulating numbers, this species can reproduce quickly.
Many are thought to have entered via Germany, where some towns are also facing infestations.
Avoid pesticides in winter to kill ants
“They are becoming more widespread because of our activities. We found them in almost all the plant nurseries we sampled last spring in the Var department,” said Professor Blight.
He said the ants are primarily dispersed on ornamental plants, and can be transferred via contaminated soils.
While winter is often a good time to target ants, which are weaker during the colder months, it can depend on the method used.
“If it’s a classical chemical (pesticide) approach, winter is not a good season because we want the workers to collect the poisoned bait and bring it back to the colony. If the idea is to remove the nest, winter may be the best period.”
The best way to tackle the invasive species, however, is early detection.
“If I have one piece of advice, it is to be vigilant in detecting the arrival of the species as soon as possible,” said Professor Blight.
“To date, this is the only way to take effective action against the species or in general against invasive ants. Once it is established in your garden, it will rapidly produce many queens and workers and, in a few years, colonise the entire garden, impacting your outdoor activities.”
Pests have regularly grabbed headlines in France over the past few years, from Parisian bed bugs to Asian hornets.
The chances of encountering them can depend on the season and the climate. Insects also work in roughly three-year cycles, so while one year might pose serious issues with wasps, the next could see more hornets and the subsequent one an overabundance of flies, according to Robert Moon, a pest control expert in Cher.
Summer
This is when you are most likely to have issues with flies, wasps, ants and hornets. There are “myriad” ways to treat them, from insecticide powders to sprays. One piece of advice Mr Moon stressed is to always read the label carefully.
He also warns that insecticides do not kill the eggs, which could then hatch and see the problem return. Vacuum regularly to destroy insects at every stage of their lifecycle.
Termites are more prolific in warmer areas, such as the south of France. Treatments include sprays, oils and “termite barriers”, which are sprayed onto soil and passed from termite to termite, eventually killing the whole colony.
Mosquitoes are also more common in warmer temperatures. They are generally more active at night, so if you start to see them earlier in the day it could be a sign of a problem. Get rid of any standing water, where mosquitoes lay their eggs and live until adulthood.
Finally, Asian hornets are now found in all regions of France. Removal requires professional pest control services, which can cost from €75 for an easy job to €200 if specialised equipment is needed.
Mice like warm spaces in colder monthsCopyright (c) 2023 Karanshama/Shutterstock. No use without permission.
Winter
Households may experience issues with rats and mice when temperatures drop.
“They are quite happy staying out in the fields in the summer, but in the winter they can be seen and heard in domestic buildings,” said Mr Moon.
You can tackle them in several ways, from sealing entry points and avoiding leaving out food, to setting traps or using rodenticide.
Spring
“Woodworm seem to be more active in spring when they come out and mate,” said Mr Moon. This can be a particular issue in older French properties. It can be treated with a woodworm solution but may require expert help.
Bedbugs can be hard to controlCopyright (c) 2016 Akos Nagy/Shutterstock. No use without permission.
All-year round
Fleas, cockroaches and bedbugs can, unfortunately, pose problems at any time of the year.
Bedbugs are mostly resistant to chemicals so the best treatment is heat. It is also one of the quickest ways to treat an infestation.
Flea treatment is the most common way to tackle fleas, but it is also important to vacuum floors and skirting boards and regularly wash your pet’s bedding.
Cockroaches can be treated with traps and repellent, but also ensure you remove food sources and clean under and behind appliances, where they might hide.
