How to control pests by blocking method?

On the basis of fully understanding the occurrence, harm, spread and spread of pests, the barrier method is a measure to artificially set up physical barriers to prevent the harm, spread and spread of pests according to the spread, infection and spread of pests. If the trunk is coated with glue and painted, some pests can be prevented from laying eggs and damaging the bark; Covering the grain surface in the granary with plant ash, chaff or inert powder can prevent the invasion of stored grain pests; Peach moth, pear moth, etc. Mainly unearthed in the form of larvae near the trunk; Female adults of mites, pear geometrid and jujube geometrid who overwinter under trees have no wings, so they have to climb from the ground to the trees to mate and lay eggs. If the trunk is coated with glue and bound with plastic film, it can be prevented from climbing on it. Fruit bagging can prevent many kinds of fruit eaters from laying eggs on fruits.