Mosquito Control across Cape Town

The mosquito keeping most Capetonians awake is Culex, a brownish mosquito that bites at night and breeds in still, often dirty water such as blocked gutters, drains, septic tanks, ponds with no fish and water features left to stagnate. Aedes mosquitoes are smaller, often with black and white markings, and bite during the day, laying their eggs just above the waterline in containers like pot-plant saucers, old tyres, buckets and blocked roof gutters. Homes near vleis and wetlands, such as those around Zeekoevlei, Rondevlei, the Milnerton lagoon and the Diep River, often see bigger swarms in warm, still weather. Inland in the Boland, farm dams, irrigation channels and water troughs add to the breeding sites. The Western Cape is not a malaria area, so the main concern locally is bites and disturbed sleep rather than disease.

Anyone who lived through Cape Town's drought years remembers the buckets in the shower and the tanks bolted to the side of the house. A lot of those habits stuck, which is good for the dams. Some of them are also quietly breeding mosquitoes a few metres from the bedroom window.

Water-saving habits that breed mosquitoes

• Rainwater tanks. An open inlet, a missing mesh filter or a lid that does not seat properly lets mosquitoes in to lay eggs. Fine mesh over the inlet and the overflow pipe sorts it out.
• Greywater buckets and drums. Shower and washing machine water left standing for days in the bathroom, laundry or garden is ideal for larvae.
• Wellpoint and borehole sumps. The pit around the pump and pipework often holds a puddle that nobody looks at.
• Pools left unfiltered. A pool whose pump was switched off to save water or power, and has turned green, can produce mosquitoes at a surprising rate.
• Water-wise gardens. Bromeliads and similar plants hold water in the cup of their leaves, and day-biting Aedes mosquitoes like nothing better.

None of this is a reason to stop saving water. Each one just needs a lid, a mesh or a regular look.

Mosquito problems by Cape Town region

South Peninsula vleis and wetlands

Homes in Marina da Gama and Lakeside sit right on Zandvlei and its canals, and Noordhoek backs onto wetland. Natural water like that cannot be drained, so the realistic aim is to stop your own property adding to the load and to protect the bedrooms, particularly on still evenings when the wind drops.

Southern Suburbs rivers and gardens

The Liesbeek and Black River run through Mowbray, Observatory and Pinelands, and leafy gardens further south hold water in ponds, fountains and old birdbaths. Big trees also block out the wind that would otherwise keep mosquitoes grounded.

Cape Flats

Sandy soil drains quickly, so garden puddles vanish fast. The exception is winter, when the water table rises and low-lying parts of Philippi, Mitchells Plain and surrounding areas can flood. Water that lingers into spring, along with blocked stormwater drains, is where the trouble starts.

Northern Suburbs, Blaauwberg and the Helderberg

Estates with water features, retention ponds near new developments and rivers such as the Kuils River and Lourens River all play a part. On the West Coast the wind helps on exposed plots, but sheltered courtyards and enclosed gardens can still hold plenty.

City Bowl and Atlantic Seaboard

There is little natural standing water here, so the source is almost always man-made: balcony pots, a sagging gutter on an old terrace in Tamboerskloof, or a neighbour's neglected pool. Flat roofs on modern blocks can pond after rain, and a blocked roof outlet will hold water for weeks without anyone noticing.

Not everything that swarms is a mosquito

Clouds of small flies dancing over reeds or around a streetlight near a vlei are usually non-biting midges. They gather in huge numbers on calm evenings and can stain walls and windows, but they do not bite. They breed in the vlei itself, so their numbers have little to do with your garden. The long-legged insects bumping around the ceiling, sometimes called mosquito hawks, are crane flies. Despite the name they do not eat mosquitoes, and they do not bite either. If you are being bitten, mosquitoes are the likely cause. If you are only being pestered by swarms, check what you are looking at first, because the fix is different. Our flying insect control page covers midges and other swarming insects.

For how a treatment works, see mosquito control in Cape Town. Local notes are in the suburb list below, for example Marina da Gama and Noordhoek.

Quick answers

Mosquito Control by suburb