Other pests-Fences, netting, and tree trunk guards can be extremely successful in limiting damage from small mammals and birds. Numerous traps are also available to catch or kill some animals. Caution: In many states it is illegal to move wildlife, including squirrels. Traps may also catch animals other than the ones targeted. Check local regulations before trapping.
Diatomaceous earth, a powder-like dust made of tiny marine organisms called diatoms, can be used to reduce damage from soft-bodied insects and slugs. Spread this material on the soil--it is sharp and cuts or irritates these soft organisms. It is harmless to other organisms. Shallow dishes of beer can be used to trap slugs.
Biological controls Biological controls are nature's way of regulating populations. Biological controls rely on predators and parasites to keep organisms under control. Many of our present pest problems result from the loss of predator species.
aphids, mealy bugs, thrips, spider mites
aphids, Colorado potato beetle
almost any insect
caterpillars that attack trees and shrubs
Parasitic nematodes (tiny worm-like organisms)
grubs, beetles, cutworms, army worms
Trichogramma wasp (extremely small, non-stinging wasps)
corn borer, cabbage looper, other worms
Seedhead weevils and other beetles
Other biological controls include birds and bats that eat insects. A single bat can eat up to 600 mosquitoes an hour. Many bird species eat insect pests on trees and in the garden. Bacillus thuringiensis (Bt) is a bacteria that specifically attacks larvae of some insect pests including white grubs in the lawn and Japanese beetles. This bacteria is harmless to desirable species.
Chemical controls When using biological controls, be very careful with pesticides. Most common pesticides are broad spectrum in that they kill a wide variety of organisms. Spray applications of insecticides are likely to kill numerous beneficial insects as well as the pests. Herbicides applied to weed species may drift in the wind or vaporize in the heat of the day and injure non-targeted plants. Runoff of pesticides can pollute water. Many pesticides are toxic to humans as well as pets and small animals that may enter your yard.
Some common, non-toxic household substances are as effective as many more toxic compounds. A few drops of dishwashing detergent mixed with water and sprayed on plants is extremely effective in controlling many soft-bodied insects such as aphids and whiteflies. Crushed garlic mixed with water may control certain insects. A baking soda solution has been shown to help control some fungal diseases on roses.
When using pesticides, follow label directions carefully. Altering the rate of application or increasing the frequency of application can injure desirable plant and animal species. Spot applications of the pesticide to the targeted pest can reduce the amount used and help reduce the risk of injury to non-targeted species. Do not apply on windy days. Read the label for information on other environmental conditions such as temperature and rain that may influence the pesticide's effectiveness. Be aware that many so-called "organic" pesticides may be just as toxic as the synthetic chemical products.