What are the control methods for underground pests of licorice?

The main underground pests at the seedling emergence stage of licorice are mole crickets and the Oriental beetle (He's Oriental chelifer), while at the mature plant stage the main ones are click beetles, scarab beetles, cutworms and darkling beetles, which cause serious damage.

After wild licorice is damaged by underground pests, because the wild root head is deep below the soil surface, it is mainly the underground stem that is eaten and damaged, and after damage the adventitious buds can grow rapidly and regenerate, so the whole plant does not die. In contrast, what is mainly eaten and damaged in cultivated licorice is the root, and the plants are young and small with weak recovery ability; accompanied by rot infection, this often leads to the whole plant rotting and dying. In large-scale artificial cultivation of licorice, it is difficult to maintain the stand of 1- to 3-year-old plants, and the main cause of missing plants and death is damage by underground pests.

The control of underground pests should focus on prevention. Before sowing, choose areas where underground pests occur lightly and where conditions are not conducive to their occurrence and damage, prepare the soil finely, and plow deeply and harrow heavily to destroy their habitat and kill the insects. Apply decomposed barnyard manure to prevent scarab grubs, mole crickets and others from being artificially brought into licorice fields. When treating seeds by pregermination and dressing, 25% phoxim emulsifiable concentrate can be used at 0.1% for seed dressing. When the population density of underground pests is relatively high, 5 kg of 2% phoxim powder per mu can be sprayed before plowing for pre-sowing soil treatment. Dig and harvest 3- to 5-year-old licorice in a timely manner.