We are invaded! But who are these aliens?

Multiple species from elsewhere have invaded our country, but what can be done? Who are they? Where do they come from?

1. An invasive alien species is a species that is native (a species naturally present in a region, country).

FALSE.
An invasive alien species (IAS) is a species that comes from another country and has been introduced outside its natural habitat, by humans, accidentally or intentionally.

2. Invasive alien species pose a threat to biodiversity.

TRUE.
Invasive alien species are a global problem. The establishment of IAS is the second leading cause of biodiversity loss worldwide. They are invasive because, once naturalized, they proliferate and expand uncontrollably (rapid growth, high reproductive capacity, significant dispersal ability, reduced regulation by pathogens or predators, etc.). They can then outcompete local species and disrupt ecosystems.

3. The term invasive alien species is equivalent to invasive species.

TRUE.
Invasive alien species can also be called invasive species.

4. The term invasive alien species or invasive species is only intended for plants.

FALSE.
The term invasive alien species refers to all living organisms. The term concerns fauna (animals) and flora (plants).

5. The butterfly bush is an invasive alien plant, but it is beneficial for butterflies.

FALSE.
The butterfly bush or David’s Buddleja is a harmful species for butterflies. While it attracts them with the scent of its flowers, it has sugar-poor nectar to feed butterflies and acts like a drug. Butterflies therefore starve, unable to feed on other plants. As buddleja invades spaces, butterflies struggle to find suitable areas, not overrun by buddleja, to lay eggs and ensure proper caterpillar development. Instead of seeking out their host plant to lay their eggs, these will be laid on the Buddleja. However, the leaves do not nourish the caterpillars. Finally, this plant is thought to synthesize aucubin, a substance toxic to the caterpillars of native species (a hypothesis that remains to be confirmed by scientific studies).

6. Buddleja is not an invasive alien species in nurseries.

FALSE.
FBI!!! False Good Idea. Just because a species is found in a nursery does not mean it is native. The origin and spread of invasive alien species are often horticultural. Taking the example of buddleja, even if you are told that most buddleja sold in nurseries are sterile, don’t be fooled! Buddleja produces so many seeds that a certain percentage of them are not sterile.

7. The European spindle is a native species and an interesting plant for biodiversity.

TRUE.
The European spindle is an interesting plant for insects as it is melliferous. It has seeds consumed by birds. In addition to its biodiversity interest, it has very pretty fruits and foliage that turns red in autumn. The European spindle is an example. Generally, one should turn to trusted nurseries offering native species for sale.

8. There is no law to regulate the spread of IAS.

FALSE.
There is European Regulation 1143/2014 on the prevention and management of the introduction and spread of IAS of Union concern. This regulation prohibits the planting, import, possession, transport, sale, purchase, and exchange of these IAS.
The European Commission has established a list of invasive alien species of Union concern. In total, 41 plants are listed among them, such as Himalayan balsam and giant hogweed. These species can no longer be commercialized, transported, or cultivated. In addition, 43 plant species included on a Walloon list of invasive alien species are subject to planting restrictions throughout Wallonia.

9. The red swamp crayfish comes from Belgium.

FALSE.
The red swamp crayfish is precisely called: The Red Swamp Crayfish! It is among the listed species of concern for our native species. It has a negative impact on aquatic plants, amphibians, fish, …

10. Invasive alien plants must be cut, uprooted, burned, covered…

TRUE and FALSE.
Invasive alien plants do not all have the same management method. Depending on the site, a diagnosis is carried out, and sometimes it will be necessary to contain rather than uproot, remove rather than leave. First, it is useful to find out about the species’ status. To find out if a plant or animal species is invasive alien, consult the reference website of our national organization Belgian Forum on Invasive Species (BFIS), a Belgian organization active for the International Union for Conservation of Nature (IUCN). Then, it is advisable to contact a reference organization to determine which measures to adopt.

11. Wallonia is active in IAS management.

TRUE.
Member States are required to implement effective management measures for IAS of EU concern established on their territory to prevent their spread. The choice of management objective (early eradication or containment and mitigation of populations) is the responsibility of the Member State.
The decree of May 2, 2019, on the prevention and management of the introduction and spread of invasive alien species aims to organize the implementation of Regulation 1143/2014.
In Wallonia, the Interdepartmental Invasive Species Unit has been responsible since November 2009 for coordinating actions aimed at limiting damage caused by invasive species in Wallonia. The SPW also dedicates a website to IAS. Discover recommendations and information: Stop Invasive Alien Species.

Does PlantC only plant alien species?

FALSE! We prioritize native species in our plantings and during our field diagnostics, we implement IAS management plans when they have been observed. We consult local stakeholders to find the best solution for managing invasive alien species.

See you soon for a True or False!