How to minimise mosquitoes in your backyard and home

Prolonged hot, humid weather has created perfect breeding conditions for mosquitoes this summer.

Mosquitoes are usually most prevalent from about December until April and Dr Prasad Paradkar from CSIRO's Australian Centre for Disease Preparedness says mosquito season started early.

"Then after the rains we have had in the past month or so in various parts of the country, and with the hotter climate, there are more mosquitoes now and it seems like there will be a big season this year," he says.

The reason this is a cause for concern is it raises the risk of outbreaks of mosquito-borne diseases such as Ross River virus, Dengue fever and Japanese encephalitis.

Dr Paradkar says only a small proportion of the 300 plus species found in Australia bite humans and "about five to 10 species out of those actually carry a virus or pathogen which can translate to humans and cause a disease".

So, what steps can you take around your home and garden to reduce mosquito numbers?

Check standing water regularly to reduce breeding opportunities

The most important step you can take to reduce mosquito numbers in your yard is getting rid of any standing water after rain events, including in your gutters. Mozzies breed in water and they don't need much of it to lay their eggs.

Although they are prolific breeders, Dr Paradkar says mosquitoes "don't fly too far, so if they breed in your backyard, they're going to stay around that area, so you want to really take care of your yard".

He recommends removing buckets, pots and pans in your garden, which can hold water and attract mosquitoes.

"The life cycle for mosquitoes is about eight to 10 days that they spend in the water, so you want to make sure you check it every week at least and empty that regularly to make sure there is no sort of wrigglers that are breeding in those spots.

"Especially in the warmer weather, the life cycle shortens, so they become adults more quickly."

The increasing popularity of rainwater tanks has also had the unintended side-effect of providing additional breeding opportunities for mozzies.

"You should check your rainwater tank to make sure there's a good mesh to cover it," Dr Paradkar says.

The entrance and overflow of rainwater tanks should have sieves, and it's worth checking for cracks if you have a plastic tank, or for rust holes if you have a metal one.

Consider introducing plants and native fish to bigger bodies of water

If you have a pond or a body of standing water that's big enough, Gardening Australia senior researcher Patrick Honan says it's a good idea to build a natural ecosystem of plants and native fish species such as rainbow fish, honey blue eyes, pacific blue eyes, yarra pygmy perch and aggasiz's perchlet.

"Mosquitoes are quite opportunistic; they'll often be the first ones that move to a body of water, but if you can encourage other things to go in there, there's this whole raft of predators that will eat the larvae."

If you are thinking about introducing other pungent plants and herbs in the hope of repelling mosquitoes, Mr Honan shares this advice.

"It is really common gardening folklore that particularly aromatic plants are going to repel mosquitoes but there is not any evidence that that is what happens at all," he says.

"What there is evidence for is essential oil concentrations, but that's like tons and tons of plant material that's been distilled down into a tiny drop. It's not the same as the plant naturally just smelling like that."

If you're heading outside — especially around dusk or in the early evening, when they are most active — wear long-sleeved shirts and insect repellent and make sure you do not bring any back inside with you.