For example, spider mites, which are tiny insect-like pests, are best controlled with Kelthane. Cowpea Curculios, which sting your peas and beans, are another exception. They require Thiodan for best control. An insecticide is effective only when it reaches the insect. The bigger they are Watch plants closely to detect early damage.
Insects are easier to control when they are small.
When they grow larger, they are easier to see, but also harder to kill. You should apply insecticides only when insects are a problem. Unnecessary applications will kill off beneficial insects that feed on insect pests such as aphids and spider mites. If the insecticide being applied, such as Sevin or Malathion , doesn't kill some pests, such as aphids or spider mites, you may create the very problem you are trying to avoid. When large infestations of destructive insects are present, weekly treatments may be necessary .