The scientific name of this insect is Holotrichia sauteri Moser, which belongs to the family Corybidae. It is commonly known as the South China Seabird. This species is mainly distributed across Guangdong, Guizhou, Zhejiang, Jiangxi, Fujian, and Taiwan provinces in China. Damage Characteristics The larvae of this beetle are particularly harmful to crops such as peanuts, sweet potatoes, and other field crops, as well as young seedlings. They feed on roots and underground parts, causing significant damage that can lead to stunted growth or even plant death. Morphological Characteristics Adults of Holotrichia sauteri can be distinguished from other species in the genus by several unique features. The hip plate is narrow, and the tip of the spine is located in the upper half or near the middle of the structure. The lateral edge of the thoracic spine is marked by small, hairless notches. The flank of the beak-like process has three tongue-like projections in the middle. The body length ranges from 18.5 to 19.5 mm, with a width of 9.5 to 10 mm. The overall color is tan with a blackish tinge, and the head and thoracodorsal plate are often darker and highly glossy. Life Habits In Fujian province, this species completes one generation per year. Adults remain in the soil during winter and emerge in late spring, typically between late March and mid-April. They are active in the late evening for mating. These adults are not strongly attracted to light. Eggs are laid scattered in the topsoil, with an average of 65.9 eggs per female. The egg stage lasts 15–31 days, while the larval stage can extend from 106 to 156 days. The pupal stage lasts 12–35 days, and adult lifespan is approximately 227.3 days for females and 217.6 days for males. Mature larvae burrow into the soil at a depth of about 25 cm. After emerging as adults, they do not re-emerge within the same year but instead overwinter underground. Control Methods (1) Strengthening monitoring is crucial for managing this pest. Since these beetles live and damage crops underground, they are difficult to detect until serious infestations occur. Therefore, it is important to conduct regular surveys from autumn through the pre-sowing period. Survey methods include selecting representative plots based on soil type, terrain, and previous infestation history. Techniques such as double diagonal or checkerboard sampling are used, with 10,000 m² to 3 samples collected, each covering 1 m². Soil is excavated to a depth of 30–50 cm, and detailed records are made of the number, developmental stage, and depth of the pests. Based on the survey results, if the density reaches 1 head/m², it is considered light; 1–3 heads/m² is moderate; and more than 3 heads/m² is severe, requiring immediate control measures. (2) Agricultural practices play a key role in prevention and control: First, deep plowing in late autumn or early winter can directly reduce populations by destroying some larvae and exposing others to freezing, drying, or predation. This method can reduce the population by 15%–30%, significantly lowering the risk of damage the following year. Second, crop rotation should be carefully planned. Fields previously planted with beans, peanuts, sweet potatoes, or corn are more prone to infestation, as adult beetles are attracted to these plants. Third, avoid using raw manure. Many pests, including chafers and leaf miners, are attracted to fresh organic matter, where they lay eggs. Applying such manure can introduce large numbers of pests into the fields. On the other hand, decomposed organic fertilizer improves soil aeration and microbial activity, promotes healthy root development, and reduces the attractiveness of the soil to earthworms. Fourth, use chemical fertilizers wisely. Ammonium bicarbonate, ammonium humate, and other nitrogen-based fertilizers release ammonia gas, which repels underground pests like earthworms. Fifth, manage irrigation properly. Soil moisture levels significantly affect earthworm activity. The ideal moisture content is 15%–20%. Too dry or too wet conditions force them to move deeper, which can disrupt their life cycle. Excessive moisture may prevent egg hatching and kill larvae. Thus, proper irrigation is essential to maintain crop health without harming beneficial soil organisms. Sixth, in greenhouses and protected areas, where temperatures are high and seedlings are concentrated, infestations can be severe. Regular inspections and timely preventive actions are necessary. (3) Chemical control options include applying 50% phoxim EC diluted 1000 times, 25% emulsifiable concentrate 1000 times, 40% dimethoate 1000 times, 30% trichlorfon 500 times, or 80% 100 insect soluble powder 1000 times. Spraying or drenching the soil can effectively manage infestations. For additional methods, refer to Mesh A. Bioantibody Biotechnology Co., Ltd. , https://www.bioantibodymedical.com