alternatives to pesticides - bugs/pests - spider mites
Actual size: 1/64”
Spider mites are found on a wide variety of plants. If the leaves start to look pale or mottled, it may be from mites sucking the juices. They are almost too small to see, but can be identified by tapping a suspect leaf over a sheet of white paper. If the little spots move, it’s likely they are mites. You may also be able to see webbing on the back of the leaf or between leaves. Spider mites especially like dry conditions. If spider mites have been a problem on your house plants, try raising the humidity around the plants by misting them regularly or setting bowls of water among them.
Water Spray - Wash spider mites off with a strong stream of water. You will need to repeat this every several days. Be sure to spray all sides of the leaves thoroughly.
Predators - Predatory mites, available from nurseries, prey on all types of harmful mites but are most effective in greenhouses. Ladybugs, praying mantis and lacewing larvae also eat mites.
Least-toxic chemical control
Alcohol – Alcohol sprays work on aphids, mealybugs, scale insects, thrips and whiteflies. Use only 70% isopropyl alcohol (rubbing alcohol): mix 1 to 2 cups alcohol per quart of water. Using undiluted alcohol as a spray is very risky for plants. Since alcohol can damage plants, you should always test your spray mix on a few leaves or plants first. Tests results should show up within 2 or 3 days
Dormant Oils - Dormant oils act by coating the plant surface and suffocating any insects that are present. Target pests are aphids, mites, scale insects, whiteflies and eggs of many pests, including some caterpillars. Dormant oils are meant for use on leafless, deciduous plants (especially fruit trees) in the winter to reduce pest populations before they hatch. If used in summer, these oils might defoliate the tree.
Horticultural Oil - Horticultural oils are also called summer oils; these are more highly refined than dormant oils, making them appropriate for use on leaves during the growing season. Consult a nursery to locate a suitable product and follow all precautions. Don’t use horticultural oils when plants are flowering.
Insecticidal soap - Insecticidal soaps are highly refined liquid soaps (technically the potassium salt of fatty acids), sometimes combined with citrus oil. Soaps are normally mixed with water and sprayed onto leaves to control spider mites, aphids, scale insects, whiteflies and other soft-bodied insects. They are contact insecticides, meaning you must wet the pest for them to be effective. As always, follow package directions and cautions when using these products. Insecticidal soaps are effective when sprayed directly on the mite. Repeated applications may be necessary.
Pyrethrum - Pyrethrum is an effective, short-lived, naturally derived insecticide made from chrysanthemum flowers. It is toxic to all insects, including beneficial ones, and moderately toxic to birds and mammals. It should be the last resort for ornamentals and is not recommended on food crops. Avoid using formulations that contain piperonyl butoxide, which is currently being evaluated for its carcinogenicity. Pyrethrins are the individual chemicals found in pyrethrum. Pyrethroids are a new array of synthetic chemicals, such as cyfluthrin and cypermethrin. They resist breakdown, thus negating their major environmental advantage. With the three names being so similar, they can easily be confused. Pyrethrum is the least hazardous.
Sabadilla - The seeds Sabadilla, a South and Central American plant, are ground into a powerful insecticidal dust. It is effective against grasshoppers, codling moth larva, webworm, aphid, cabbage looper, chinch bug and many household pests. It can irritate mucous membranes and cause sneezing. Honeybees are vulnerable to it. Handle it carefully.