The battle against Wasps, the Alien Invaders

Like something out of an extra-terrestrial movie, wasps are the alien species that descend upon our home-town, the bad guys that no one really asks for, but that always seem to show up without any warning or invitation.

Areas of infiltration

Hostile wasp species have recently invaded Cape Town – spreading their troops across the Western Cape in the areas of Brackenfell, Kraaifontein, Kuils River, Stellenbosch, Somerset West, Gordon’s Bay, Paarl, Grabouw, Franschhoek and Wellington. If not controlled, these stinging insects may even spread to other neighbouring areas and even provinces where the climate is more favourable.

Over the last five months, the City of Cape Town’s Invasive species unit has determinedly been working to get rid of wasps. Thus far almost 5000 nests have been removed – and counting! In fact, another team has been put in place to fight the battle against invasive wasps and almost R700 000 has been spent in efforts to rid the Western Cape of wasps since the problem started in October 2014, and we still have a way to go as they only hibernate in the winter months.

But, why are these wasps classified as invasive?

So why are these wasps classified as invasive alien species, you might ask. The European paper wasp species (into which family the German wasp falls) are listed under NEMBA (National Environmental Management Biodiversity Act) Category 1b invasive species. This means that they require control via means of an invasive species management programme. It has been reported that the German wasp species have infiltrated the honey bee hives and killed them. As honey bees are a protected species, this poses a threat to the ecosystem. They also pose risks to the beekeeping, as well as deciduous fruit and wine industries; some workers have been stung while industriously doing their jobs on fruit farms!

The stinger: the weapon of choice

According to our Entomologist, Jaco Scheepers, most insects have an “ovipositor”, such as crickets for example which allows them deposit their eggs. However, for members of the Hymenoptera order, which include bees, wasps and ants, this organ has been reduced into a stinger. Interestingly enough, Scheepers also says that when it comes to wasps, size does matter. With these sleek and shiny Hymenopterians, it truly is the case of the bigger the wasp the more painful its sting. Mind you, I’ll be sure to stay from any wasp, as not only do they give a painful sting, but unlike bees that sting once, these violent insects can sting repeatedly.Thankfully, I can count myself as one of the lucky ones who haven’t come in the line of fire!

When comparing wasps to honey bees, there is good news and bad news. Whilst the stings of wasps are very painful, no serious allergic reactions take place (such as anaphylactic shock), as is the case of bees. This is because wasps do not inject the same harsh proteins as bees do during stinging. Unfortunately, wasps have smooth stingers (honey bees have microscopic hooks on their stingers) which means that the stinger can be pulled out of the victim’s skin without injuring the wasp. This enables the wasp to sting repeatedly.

Wasp Prevention Tips

The early treatment of a wasp nest is essential to make sure you keep your family and pets safe from wasp stings. Below are a few prevention tips you can practice to prevent wasps:

• Be sure to look if there are any nests on your property during early spring. Early on they will be walnut or golf ball in size, and these early small nests have fewer wasps and are much easier to treat quickly.
• Ensure your outside bins have lids that fit securely. Keep bins at a distance from doors and windows to make sure that wasps are not attracted to the contents.
• Prevent wasps from entering your home by keeping windows and doors closed, or fit fly screens in front of windows and doors.
• If you have spotted a nest, make sure you keep children and pets away from the area.

Although Rentokil does not generally treat for wasps, for peace of mind and to be completely safe from stings, it is safer to let a professional treat the nest for you. If you have a wasp problem, contact the Invasive Species Unit by logging the record on the City of Cape Town Spotter Network at www.capetowninvasives.org.za or contact your local wasp control operator.