1, grubs eat germinated seeds, bite off the roots of seedlings, and the fracture is neat and smooth, which often causes seedling death, from lack of seedlings to broken ridges, and then seriously damages seeds. 2. Flammulina velutipes is a polyphagous pest, which mainly harms larvae. It eats the fine roots and tender stems of newly sprouted seeds or seedlings, causing the seedlings to die, and the injured parts of the rhizomes bitten by Flammulina velutipes are filiform. 3. The adult and nymph of Gryllotalpa are seriously damaged. Bite the newly germinated seeds, especially the sown seeds, or bite the tender roots and stems, and bite off or chop the stems into a ball, so that the seedlings wither and die, resulting in lack of seedlings and broken ridges.