Over the past few months, with the warmer summer temperatures, the City of Cape Town has been battling with an invasion of yellow and black insects, commonly known as the German wasp (Vespula germanica) and European Paper wasp (Polistes dominula).
The wasps emerge in the early summer, with numbers increasing steadily well into autumn. Known for their aggressive behaviour and venomous sting, these invasive wasps frequently spoil outdoor activities and are harmful to our natural ecosystems.
The predatory success of these invasive wasps is often attributed to their adaptive behaviour, together with their cognitive abilities. They locate food sources and prey using their visual, auditory, and olfactory senses and can learn to follow pheromone scents to source prey.
Coupled with the fact that they are omnivores with a broad diet – honeydew, nectar, other insects and spiders, vertebrates and carrion – they are very adaptable and can exploit whatever food source becomes available. In short, they are excellent foragers and resilient insects, which makes them extremely challenging to control and extirpate.
The City’s Invasive Species Unit has four operational teams to assist with the removal of the wasps across Cape Town. However, given the significant increase in wasp reports, the City has assigned an additional four teams to shorten the turnaround time for requests, and these teams will be operational by Friday, 4 March 2022, if all goes as planned.
How to distinguish the South African Paper Wasp and Cape Honey Bee from the German Wasp and European Paper Wasp:
“The City has a special online reporting tool where residents can report wasp sightings. I urge residents to please sign up and to report the sightings of these invasive wasps so that we can take action. This service is free of charge, however, those who cannot wait for the City’s operations team can also make use of a professional service provider. We are trying our best to improve our turnaround time and this is why we have doubled the number of teams working across the metropole. Each team will respond to reports on a first-come-first-serve basis, which is assembled from reports received on our reporting tool,” said the City’s Deputy Mayor and Mayoral Committee Member for Spatial Planning and Environment, Alderman Eddie Andrews.
How to report:
Sign up for the Spotter Network at www.capetowninvasives.org.za
Log your sighting on the Spotter Network
Log the date and the locality, or specific location, of the invasive wasp sighting
The Invasive Species Unit has operational teams that will assist on a first-come-first serve basis
Or phone 021 444 9835
Why are they a problem?
In urban areas, the German Wasp and European Paper Wasp have the potential to become a serious pest and annoyance to humans. German Wasps are pests of stone fruit and grape cultures, and enemies to the honey industry as they hunt and kill honeybees.
They have a disruptive impact on a variety of ecosystem processes. The most obvious effect would be on native arthropod species, which the German Wasp directly preys on.
How do they spread?
Accidental human-aided transport of hibernating queens or active nests is the central driver of the current distribution of these wasps. Coupled with conducive climate ranges and little to no natural enemies, these wasps outcompete our indigenous species negatively affecting native food webs.
What does the law say?
Under the National Environment Management: Biodiversity Act (NEMBA), Act 10 of 2004, the German Wasp and European Paper Wasp are designated as Category 1b Invasive Alien Species. This legislation states that:
These wasps need to be managed as part of an invasive species control plan;
Once the control plan has been adopted in an area, no person may relocate or disperse these wasps
“I want to thank the teams working on this challenge for their commitment to get the job done as soon as possible. At the same time, I’m asking residents to please assist us in fighting these invasive species by reporting sightings,” said Alderman Andrews.
Pictures: COCT / Unsplash