Battle to control invasive wasps

The City has spent more than R680 000 on controlling invasive wasps since October, when the wasp season started.

The season usually ends in May, depending on the weather, when the wasps go into hibernation for the winter months.

The City’s Invasive Species Unit has removed more than 4 800 invasive wasp nests over the past five months.

In February, the City trained a second team to tackle the insects in re- sponse to the increasing calls from the public.

The City has partnered with the South African National Biodiversity Institute (SANBI), the Department of Environmental Affairs, Stellenbosch Municipality and Stellenbosch University, to pool resources and train a dedicated Invasive Wasp Control Team, equipped with special suits and equipment, to manage the invasive wasps (“Invasive wasps invading Constantia,” Bulletin, February 5, 2015).

Johan van der Merwe, mayoral committee member for energy, environmental and spatial planning has urged residents to be patient as the Invasive Wasp Control Team attends to the logged calls.

“Sightings are being reported daily, therefore having a second Invasive Wasp Control Team on the ground will assist with addressing the backlog of over 500 requests for wasp nest removal,” he said in a statement.

“The City’s Invasive Wasp Control Team has been doing its best, working tirelessly, six days a week to respond to the high volume of calls regarding invasive wasps. Therefore the City urges residents to be patient as the requests for the removal of nests are dealt with according to the order in which they are received.”

Private homeowners would have to call in a pest control company should they require more urgent assistance.

“Property owners are primarily responsible for pest control on their premises, and the City assists according on its available capacity.

“Property owners are urged to send a report containing their street address and the number of nests removed to invasive.spe- cies@capetown.gov.za as this helps with the City’s future planning and research.”

Residents are advised that the sting from these wasps is particularly painful.

There are numerous reports of the German wasp stinging workers harvesting grapes and other fruit, the City says. The wasps also present a hazard to residents who unintentionally disturb a colony.

Both alien invasive wasp species, the European paper wasp (Polistes dominula) and the German wasp (Vespula germanica), are listed as a Category 1b invasive species in the Alien and Invasive Species Regulations, National Environmental Management Biodiversity Act (No 10 of 2004).

This means that scientists have agreed the wasps have to be removed by law as they pose a threat to the local ecosystem and several important industries such as deciduous fruit, wine and beekeeping industries. Beekeepers have reported with dismay that German wasps have infiltrated several local bee hives and have killed honeybees, the City says.

The European paper wasp is highly invasive and is spreading rapidly. The most severe infestations have been found in the northern suburbs but nests have been spotted as far as Morningstar on the N7, Bothasig, Athlone, Wetton, Plumstead and Woodstock.

A large population of wasps was discovered in Constantia.

The German wasp is known to be more aggressive than the European paper wasp and appears to be less densely distributed in the urban areas.

Originally found at Kirstenbosch, nests have been sighted in Constantia, Eerste River, Paarl and Stellenbosch.

There are two ways in which the Invasive Species Unit can be reached: by logging the record on the City of Cape Town Spotter Network at www.capetowninvasives.org.za or residents can send an email to invasive.species @capetown.gov.za stating that wasps are in their suburb in the subject line, with their address, contact details and a map of their location in the body of the email. There is a longer waiting time for emailed reports, the City says.

Alternatively visit www. capetowninvasives. org.za or www.facebook. com/ ctinvasives