Biological insect control Many very effective biological pest controls have become available during the past twenty years. These naturally occurring pathogens destroy specific insects but do not harm other creatures that inhabit the same environment. This bacterium kills many kinds of insect larvae by paralyzing the digestive system. Bt is sold as a dust or liquid under such trade names as Dipel and Thuricide. Once the bacterium becomes established in the soil, it can effectively control the Japanese beetle population in your yard for up to twenty years.
Most natural insecticides are less toxic than synthetic chemicals.
They don t accumulate in the environment or in animal tissues, and most insects don t readily develop resistance to them. Still, they can upset the ecological balance in your garden because some of them will also kill beneficial insects and honeybees. They should be used with caution and care. Be aware of any specific toxicities indicated on the label, and spray late in the day when honeybees have returned to their hives. Always wear a mask and remove contact lenses when applying dusts, and wear gloves and protective clothing when applying any kind of insecticide.