The best way to conserve natural crop defenders is to avoid the use of toxic chemicals. But in addition to this, the farmer can do more to protect beneficial insects and spiders.
IPM farmers will try to create an environment that is optimal for the development of beneficial insects. By growing border crops the farmer can provide them with extra shelter and food. Especially flowering plants (e.g. beans) are very useful as they attract parasitic wasps that feed on the nectar.
After harvesting of a rice crop, the populations of natural defenders will decrease rapidly as there are no pest insects to feed on. Plowing of the fields will kill many spiders and other beneficial insects as they have no place to hide.
By placing straw on the dikes surrounding the fields, the farmer can provide a shelter where they can hide and survive until the next season. Many small insects that are present in this decomposing plant material serve as a source of food for spiders and other predators.
To augment the number of beneficial insects the farmer can even rear them and then release them in the field by using special emergence boxes.