DEAR JOAN: The other day, I was out in my backyard enjoying the sunshine and to my surprise a mosquito landed on my arm looking for a meal. It did not succeed.
A few moments later another one appeared with the same intention. When I saw them, I wondered where they were coming from. I thought to myself it seems too early for mosquitoes.
Later that afternoon, I was transplanting some seeds I had germinated into potting soil. I grabbed some rainwater from the covered storage barrel. Inside the clear plastic container I could see mosquito larvae squirming in the water. I had found the mosquito source and I proceeded to pour some vegetable oil on the surface of the water to suffocate them.
All the rain we have had this winter will create lots of habitat for mosquitoes. Folks need to be vigilant about removing any standing water to prevent these pests from becoming a big problem this year. Could you also discuss ways to kill the larvae if found in water that you are saving.
Andy Kobayashi, Antioch
DEAR ANDY: The best way to deal with mosquito larvae is to prevent them in the first place.
The mosquito hunter’s adage is that if it can hold water for a couple of days, it can serve as a breeding ground for mosquitoes. Things such as empty flower pots and saucers are common sites, but both house and street gutters, old tires, leaky spigots, and knotholes in trees can and do host mosquito larvae.
Mosquitoes also are a year round threat, not just in the spring and summer.
Everyone should make a thorough inspection of their home and yard, emptying any standing water that has accumulated, even if you think it’s impossible that it could support mosquito life. Researchers say a bottle cap is big enough to get things going.
Going forward, check those areas after a rain, or if your irrigation system tends to be exuberant. For areas intended to hold water, here are some suggestions for keeping them larvae free.
- For water barrels, use natural oils — olive or vegetable. You only need about 1 teaspoon of oil per gallon of water. Do not use on ponds or other areas that support fish life.
- Apple cider vinegar is another good way to get rid of the mosquito larvae. It’s non-toxic and won’t harm other creatures that might get into the water. The draw back is that it takes almost two days to work. The ratio is about 15 percent vinegar to 85 percent water. You can go stronger, but don’t go weaker or it won’t work.
- Ordinary hand, dish washing or insecticidal soap also can help control mosquito larvae. It only take a tiny bit — a single milliliter to a gallon of water — to kill larvae.
- Mosquito dunks are a safe and effective way to control larvae. The dunks contain a bacteria that is fatal only to the mosquito larvae and won’t harm other creatures living in or drinking from the water source.
- For larger areas, you can try mosquitofish (Gambusia affinis), which are available from a mosquito abatement district in your county.
- You also could install a bubbler or agitator that would turn still water into active water.
Tips for controlling mosquitoes before they get out of hand