The scientific name of this insect is Holotrichia sauteri Moser, belonging to the family Corybidae. It is commonly known as the South China Seabird. This species is found in provinces such as Guangdong, Guizhou, Zhejiang, Jiangxi, Fujian, and Taiwan. Damage Characteristics The larvae of this beetle are particularly harmful to crops such as peanuts, sweet potatoes, and other field crops, as well as seedlings. They feed on the roots, causing significant damage and even plant death in severe cases. Morphological Characteristics One distinguishing feature of Holotrichia sauteri compared to other species in its genus is the narrow hip plate and the apex of the spine located in the upper half or near the middle. The lateral edge of the thoracic spine is completely broken by small, hairless notches. The beak-like process on the flank has three tongue-like projections in the middle. The adult measures 18.5–19.5 mm in length and 9.5–10 mm in width. The body color is generally tan with a blackish tinge, and the head and thoracodorsal plate are usually darker and more shiny. Ecological Habits In Fujian, this species completes one generation per year. Adults live in the soil during winter and emerge in late spring, typically from late March to mid-April. They are active in the late evening, mating and feeding. Their phototaxis is weak, so they do not respond strongly to light. Females lay eggs scattered in the topsoil, with an average of 65.9 eggs per female. The egg stage lasts between 15–31 days, while the larval stage can extend for 106–156 days. The pupal stage lasts 12–35 days, and adults live up to 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, adults do not re-emerge in the same year but instead overwinter underground. Control Methods (1) Strengthen Monitoring: Since these pests live underground and are hard to detect, early detection is crucial. Surveys are typically conducted from autumn to just before sowing. The method involves selecting representative plots based on soil type, topography, and previous infestations. A grid system or double diagonal sampling is used, with 10,000 m² divided into 3 samples, each 1 m². Soil is excavated to a depth of 30–50 cm to check for larvae and other pests. The number of individuals per square meter is recorded, and according to Liaoning Province's guidelines, 1 head/m² is considered light, 1–3 heads/m² is moderate, and above 3 is serious. Immediate action is required if the threshold is exceeded. (2) Agricultural Control Measures: First, plowing in late autumn or early winter can help reduce populations by directly destroying some larvae and exposing others to freezing, drying, or predation. This can reduce the population by 15%–30%. Second, avoid planting crops like beans, peanuts, sweet potatoes, and corn in consecutive years, as these are highly susceptible to infestation due to adult feeding habits. Third, avoid applying raw manure, as it attracts pests like chafers and leaf lice, which may lay eggs in it. Instead, use decomposed organic fertilizer to improve soil structure and promote healthy root growth, which helps crops resist pests. Earthworms also tend to avoid mature compost, reducing their impact on crops. Fourth, use chemical fertilizers like ammonium bicarbonate and ammonium humate, which release ammonia gas that repels underground pests. Fifth, manage irrigation carefully. The ideal soil moisture for earthworm development is 15%–20%. Too dry or too wet conditions force them deeper into the soil or prevent egg hatching and larval survival. Proper irrigation ensures crop health without favoring pest activity. Sixth, in protected environments like greenhouses, where temperatures are high and seedlings are dense, infestations can be severe. Regular monitoring and timely intervention are essential. (3) Chemical Control: Apply 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. These can be sprayed or applied as a soil drench. For additional methods, refer to Mesh A. BK100 Bioantibody Biotechnology Co., Ltd. , https://www.bioantibodymedical.com