Malathion is a chemical compound known as an organophosphate. Used as an insecticide, malathion interferes with nerve impulses in an insect's nervous system, preventing signals from stopping. The constant signaling renders the insect unable to breathe or move, and it dies. On fruit trees, malathion kills leaf-chewing and sucking insects when properly mixed and applied according to label instructions. In wettable powder, emulsion or liquid form, malathion is mixed with water and applied with a sprayer.
Read label directions for the malathion product selected. Malathion is commercially available in different strengths -- such as 50 percent, 57 percent and 25 percent -- and forms -- emulsions, powders, liquids. If you are not certain how much water your sprayer tank holds, check the tank for this information.
Fill your spray tank one-half to two-thirds full of water. If you have a sprayer with an agitator, turn on the agitator by turning the valve. The agitator will help mix the chemicals with the water.
Measure the amount of malathion product as indicated for the size of your sprayer and the recommended strength for your fruit tree.
Pour the measured product into the tank with the water. Pour water into your measuring cup and pour that water into the tank. Repeat two or three times to rinse your cup.
Finish filling the tank with water to the full line. The action of flowing water into the tank is generally enough to mix the product with the water. If powder continues to float, agitate -- stir with a clean rod if the tank does not have an agitator -- until the powder is in complete suspension with no floating lumps.
Things You Will Need
- Malathion product
- Measuring cup (optional)
- Spoon measures (optional)
- Tank sprayer
- Malathion is sometimes combined with horticultural oils for winter or early spring application. Follow label directions when combining products. Consult your local Cooperative Extension Service for recommendations for specific fruit trees.
- Follow precautions on the product label for minimal intervals between spraying and pre-harvest spraying termination.
- Never spray malathion on trees that have blooms; it will kill the bees that pollinate the plant.
- Read and follow all health warnings. Malathion exposure can affect the nervous system of human beings in a similar manner to its effect on insects.
- Be aware of recommended first aid measures for breathing malathion vapor or contact with skin.
- Dedicate all equipment used for measuring and mixing malathion to insecticide spraying only.
- Food Protection Services: Malation 50% Emulsifiable Insecticide
- Texas A&M System College of Agriculture and Life Sciences: Malathion 5 EC
- Colorado State University Extension: Backyard Orchard Apples and Pears
- Spectracide: Malathion Insect Spray Concentrate
- National Pesticide Information Center: Malathion General Fact Sheet
- Agrian: Malathion 8-E Insecticide
- Comstock Images/Comstock/Getty Images