3 Common Pool Pests and How to Get Rid of Them

Before you hold your first pool party this summer, you might want to make sure that your pool is not playing host to three uninvited guests that you really don't want to find there.  Mosquitos, water boatmen, and backswimmers make up this unholy trinity of unwelcome gatecrashers; here's how to recognise and eliminate them.

Identifying Your Pool Invaders


Mosquitos are potentially dangerous pool invaders because they can carry diseases such as malaria and other unpleasant viruses.  Mosquitos feed on the blood of mammals and vertebrates, which they suck up using a needle-like mouth part or proboscis.  It's during the injection of the proboscis that tiny amounts of residual infected blood can be transferred to the victim.  If you're bitten by a mosquito, at the very least you could be left with an irritating, itchy swelling at the bite site.

'Mozzies' are often mistaken for harmless flies.  However, look closely and you will see that the mosquito has two wings, hairy scales over their bodies, and that long, needle-like mouthpart that inflicts injury on unwary bathers.

Mosquitos are attracted to stagnant or lying water because this is where they breed and lay their eggs.

Water Boatmen

Water boatmen are innocuous, harmless insects that get around by skating across the surface tension of the water, swimming beneath it, or flying.  These insects are small, oval-shaped, and brownish-grey in colour. 

Water boatmen are attracted by algae and green plant matter that you may find growing around your pool, especially in drains, taps, and filters.  The aquatic vegetation provides food for the water boatmen, as well as somewhere safe to lay their eggs.  Water boatmen also eat mosquito larvae and will therefore be attracted to your pool if you have mozzies in residence.

Backswimmer (Water Wasp)

Backswimmers are your number one nightmare guest at any pool party.  Also known as the water wasp, they have a very painful bite.

Backswimmers look similar to water boatmen, but are considerably larger.  They lurk beneath the surface of the water but can also fly.  Like water boatmen, backswimmers lay their eggs on vegetation and algae around your pool area.  They prey on small insects, water boatmen being a particular favourite.

These three pests are almost inextricably linked because of their feeding and breeding habits.  Mosquito larvae are a favourite food of water boatmen that in turn are the main prey of backswimmers.  Therefore, where you find one, you will probably find all three.

How to Rid Your Pool of Mosquitoes, Water Boatmen, and Backswimmers

The most effective way to deter all these pool party gatecrashers is to remove their food source and deny them of a place to breed.

  1. First of all, shock your pool by administering several doses of chlorine.  Get rid of all traces of algae from the bottom and sides of the pool, and then give the filters a thorough clean.  You may need to repeat this process a few times until all traces of green are gone.  
  2. Each time you've shocked and scrubbed your pool, take a skimmer and remove any water boatmen, backswimmers, and greenery floating on the surface.  Carefully put the insects in a bucket of water and oil to kill them.  
  3. In order to prevent further algal growth, increase the chlorination levels in your pool, and be sure to clean out the filters frequently.  If you have an auto-water re-filler in your pool, put a chlorine tablet inside it to stop more algae from gaining a foothold.  
  4. If your pool is frequently plagued by the regrowth of algae, treat it with a proprietary algaecide, available from a good pool supplies store.

When the mosquito larvae and water boatmen have gone, the backswimmers will also vanish, leaving you and your guests to enjoy your pool unmolested by biting pests. 

For more advice on maintaining your swimming pool and keeping it an algae-free zone, have a chat with one of the friendly experts at Shenton Pumps.

Picture inside of a pool