Tea is not only the national drink of China but also one of the oldest and most widely consumed beverages in the world. The production of tea relies on the cultivation and management of tea trees. Tea gardens, where these trees are grown, form complex ecosystems. Besides tea trees, many other organisms coexist in these gardens, contributing to the ecological diversity. However, this diversity can also pose problems, as some organisms negatively affect tea trees and tea leaves, leading to pest and disease issues. These are significant constraints to tea production and major threats to tea safety.
In our series on tea garden pest control, we introduce you to various tea garden pests, their habits, damage mechanisms, and control methods. Through this series, we aim to deepen your understanding of tea garden pests, helping you better protect tea gardens and ensure the best environment for tea leaf growth. In this fourth installment, we focus on the common tea garden pest: the Tea Leafroller.
Identification of Tea Leafroller
The Tea Leafroller (Archips micaceana) is a moth belonging to the Tortricidae family. It primarily affects tea trees and Camellia species. The larvae prefer to feed on young leaves, initially mining the undersides of leaves before rolling the edges and feeding inside the rolled areas. Later, they roll the leaf tips into triangular pockets to continue feeding. This not only reduces yield but also contaminates tea leaves with their excrement, affecting tea quality.
Morphological Characteristics and Life Cycle:
Adult Stage: Adults are 4-6 mm long with a wingspan of 10-13 mm. Their heads and thoraxes are dark brown, with black compound eyes and yellow hairs on the face. The antennae are filiform and brown. Forewings are brown with a purple sheen and a distinctive golden triangular mark near the center. Hindwings are dark brown with long fringes.
Egg Stage: Eggs are 0.3-0.48 mm long, flat, oval, and colorless, with a water droplet-like sheen.
Larval Stage: Last-instar larvae are 8-10 mm long, creamy white, semi-transparent with brown mouthparts, and black simple eyes. The body has short white hairs, appearing slightly flattened initially but becoming cylindrical later, revealing the green to purple-black digestive tract.
Pupal Stage: Pupae are 5-6 mm long, cylindrical, and light brown, with yellowish wings and red-brown compound eyes.
Damage Characteristics:
The Tea Leafroller mainly targets young leaves, causing damage by leaf mining, edge rolling, and forming triangular pockets that resemble "dumplings." This damage is easy to recognize. The larvae's excrement accumulates inside the pockets, and if these pockets are picked during tea harvesting, they significantly degrade tea quality.
Control Methods of Tea Leafroller
Considering the characteristics and severity of Tea Leafroller infestations, the following control methods are recommended:
Manual Removal: Since Tea Leafrollers mainly harm young shoots, timely manual removal of rolled leaves and triangular pockets can be effective.
Protect Natural Enemies: Natural enemies of Tea Leafrollers are abundant. Avoid using chemical pesticides when possible. When controlling other pests, manage the timing of physical controls like sticky boards and insect traps to minimize harm to parasitic wasps and spiders.
Pheromone Trapping: Use pheromone traps for monitoring and controlling adult Tea Leafrollers, focusing on overwintering and first and second generations to reduce the pest population throughout the year.
Light Traps: Tea Leafroller adults are attracted to light. During peak periods, light traps can reduce the adult population.
Yeehar Agriculture has been deeply involved in green pest control, developing products in the natural enemy-friendly, pest monitoring, and trapping series to achieve the goals of disaster prevention, loss reduction, quality improvement, and safety assurance. Here are some methods for controlling Tea Leafrollers:
1. Multi-functional Insect Traps: These traps use pheromone technology to attract Tea Leafrollers and then kill them with a high-voltage grid. Powered by solar energy and lithium batteries, they are long-lasting and easy to install, effectively controlling Tea Leafroller populations in the area.
2. Solar Insect Light Traps: Designed specifically for capturing small insects, these traps are highly efficient in monitoring and controlling Tea Leafrollers. They are widely used in agricultural research, field monitoring, and pest control in tea gardens.
3. Boat-shaped Pheromone Traps: Pheromone technology is a leading measure in green pest control for tea trees, serving as an important alternative and supplement to chemical pesticides. Boat-shaped traps are particularly effective for Tea Leafroller capture, making them ideal companions for pheromone lures.
Precautions for Controlling of Tea Leafrollers
When controlling Tea Leafrollers, the following precautions should be observed:
Timing: Due to the overlapping generations of Tea Leafrollers, with extended periods of larval and adult presence, continuous monitoring is essential to determine the optimal control times.
Integrated Methods: Single control methods may be ineffective. Combine agricultural, biological, and chemical control methods, rotating insecticides to prevent resistance.
Tea Safety: Ensure the safety of chemicals used to avoid exceeding residue limits in tea leaves. Protect natural enemies to maintain ecological balance.
Effectiveness Assessment: Regularly evaluate the control measures and adjust strategies accordingly to ensure tea yield and quality remain unaffected.
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