Key Points of Green Prevention and Control Technology for Tomato Leafminer

The tomato leafminer (Tuta absoluta) is a major pest in tomato production and also poses a threat to other Solanaceous crops such as eggplant, potato, pepino, and tobacco. According to predictions, the overall nationwide occurrence in 2025 is expected to be moderate, with some regions experiencing severe levels. The damage is more severe in protected cultivation than in open fields, and autumn crops are more affected than spring crops. The peak damage period occurs from tomato flowering to fruit maturity. Effective measures are required to mitigate the potential risks of tomato leafminer to ensure the safety and quality of vegetable production.

I. Prevention and Control Goals

The coverage rate of control measures in major tomato-producing areas should exceed 90%, with a control effectiveness of over 80%, and economic losses kept below 10%.

II. Prevention and Control Strategies

Following the principles of “source control, regional management, and green prevention and control,” efforts should be made to strengthen pest monitoring and early warning systems, prioritize agricultural, physical, and biological control methods, and use low-toxicity, low-residue pesticides scientifically and rationally when necessary to comprehensively enhance green prevention and control effects.

III. Key Prevention and Control Areas

Key areas include Xinjiang, Yunnan, Guizhou, Sichuan, Chongqing, Hunan, Guangxi, Shaanxi, Inner Mongolia, Liaoning, Gansu, Ningxia, Qinghai, Shanxi, Hebei, Shandong, Tianjin, and Beijing. Continuous monitoring and early warning should be strengthened in non-affected areas to detect and prevent the spread of the pest in time.

IV. Technical Measures

(1) Pest Monitoring

Monitoring Targets: The primary focus is on tomatoes, while also considering other Solanaceous crops such as eggplant, potato, pepino, tobacco, and goji berry, with black nightshade weeds used as indicator plants.
Monitoring Period:
- Seedling Stage: From sowing to seedling emergence.
- Transplanting Stage: From transplanting to the end of the growing season.
Monitoring Methods:
- Open-field tomatoes: Install three adhesive pheromone traps per field. During the seedling stage, arrange traps in an equilateral triangle, with a spacing of about 50 meters and at least 5 meters from the field edge. During the mature plant stage, place them in a straight line along the field ridges, with a spacing of 50 meters and about 1 meter from the field edge.
- Protected cultivation tomatoes: Install two traps per greenhouse—one at the entrance and one in the middle during the seedling stage, at least 1 meter from the edge. During the mature plant stage, place them along the aisles, about 1 meter from the field edge.
The traps should be placed 10-20 cm above the ground, and trap counts should be recorded every three days. Sticky traps should be replaced promptly, and pheromone lures should be changed every 30 days. The use of intelligent pest monitoring devices is encouraged.

(2) Prevention and Control Technologies

1. Agricultural Control

Crop Rotation: Rotate with non-Solanaceous crops or implement rice-upland crop rotation.
Use of Pest-Free Seedlings: Avoid introducing seedlings from infected areas; recommend centralized seedling cultivation in insect-proof net nurseries to prevent early-stage transmission.
Field Sanitation: Completely remove weeds and Solanaceous crop residues from the field. Pruned branches and discarded fruits should be promptly collected and destroyed. Before pulling up plants, apply pesticides and then clear the residues for plastic film fermentation treatment.
Environmental Control: In winter, maintain low temperatures for at least 30 days; in summer, implement high-temperature greenhouse treatments to significantly reduce pest populations.

2. Physical Control

Insect-Proof Nets: Install 60-mesh insect-proof nets at greenhouse entrances and ventilation openings to effectively prevent pest invasion.
Light Trapping: During peak pest periods, install one insecticidal lamp per 5-10 acres in open fields and one per greenhouse in protected cultivation. The lamp height should be maintained at 0.5-1 meter. Water traps should contain 0.2% detergent solution to enhance effectiveness.

3. Application of Pheromone Technology

Mating Disruption: Before transplanting, use mating disruption techniques such as twist ties, confusion dispensers (about 60 per acre), or intelligent aerosol dispensers (one set per 3-5 acres). These should be arranged in a large contiguous area, with denser placement on the periphery and more spaced out in the center.
Pheromone Trapping: In open fields, install 8-10 triangle or winged pheromone traps per acre at a height of 10-20 cm. In protected cultivation, use blue sticky traps, colored water basins, or bucket traps placed on the ground.

4. Biological Control

Ecological Regulation: Plant nectar plants (e.g., marigolds, sesame, buckwheat, and tartary buckwheat) around fields and ditches to attract and protect natural enemies while reducing the use of broad-spectrum insecticides.
Release of Natural Enemies: When adult tomato leafminers are detected, release Trichogramma pretiosum, Trichogramma achaeae, Orius laevigatus, or Macrolophus pygmaeus for biological control.

5. Scientific Chemical Control

Chemical control should be applied 5-8 days after a significant increase in adult moth counts (3-5 times the previous day’s count) or when the first larval mines are detected. Spraying should be done in the evening or on rain-free afternoons, ensuring thorough coverage, especially on the undersides of leaves.

Recommended biopesticides include Bacillus thuringiensis strain G033A, Beauveria bassiana, and spinosad. Field trials have also validated the efficacy of legally registered low-toxicity chemical pesticides such as abamectin, emamectin benzoate, chlorantraniliprole, flubendiamide, and rotenone. Pesticide rotation should be practiced, and strict adherence to safety intervals is required.