I. Occurrence Pattern

The Tea green leafhopper, belonging to the Hemiptera order and the Cicadellidae family, is one of the primary pests of tea plants. Both adult and nymph stages of this pest suck sap from buds and leaves; female adults lay eggs within young shoots, damaging the conducting tissues. Affected buds and leaves turn yellow along the margins, veins become red, and the leaves curl and become coarse. Growth of the buds and leaves may halt, and in severe cases, the entire Leaf may wither and fall off, significantly impacting tea yield and quality.

In our city, the tea green leafhopper has nine generations per year. Overwintering adults start to become active when temperatures rise above 10°C around late April. Signs of damage appear in some tea gardens by mid-July. The peak period for damage occurs between mid-August and mid-September. The timing of this peak is closely related to temperature in January and February, as well as rainfall in June and July. Both adults and nymphs of the tea green leafhopper have a preference for tender growth.

II. Control Methods

1. Agricultural Control

The tea green leafhopper lays its eggs in new shoots of tea plants. Timely harvesting of these new shoots can reduce the number of eggs and lower pest density, thus mitigating the extent of damage.

2. Physical and Chemical Luring

Between mid-August and mid-September, hang yellow sticky traps in tea gardens to trap adult tea green leafhoppers. Use 25-30 sticky traps per acre, suspended 10-15 cm above the canopy (pheromones can also be added to the traps to improve trapping efficiency).

3. Biological Control

(1) Protection of Natural Enemies. Enhance the ecological environment of tea gardens to protect natural enemies such as spiders, wasps, lacewings, ladybugs, and ground beetles that prey on the tea green leafhopper.

(2) Plant-Derived Insecticides. At the beginning of the damage period (usually early August), when the population reaches 9 insects per hundred leaves, apply plant-derived insecticides such as azadirachtin, cephalanthin, matrine, and rotenone.

(3) Biological Preparations. In areas or seasons with high humidity, it is recommended to spray Beauveria bassiana spores at a concentration of 8 million per milliliter to effectively reduce the population of the tea green leafhopper.

4. Chemical Control

Before the peak damage period (usually mid-August), when the population reaches 12 insects per hundred leaves, use efficient and low-toxic chemical pesticides such as indoxacarb, chlorfenapyr, and flubendiamide. Follow the dosage and application instructions provided in the product manuals. Focus spraying efforts on the middle and upper parts of the leaves.

Contributed by: Agricultural Technology Center of the City's Department of Agriculture and Rural Affairs