Rhododendron/Azaleas has few species of pests throughout the growing season.

The main insect pests are: stephanitis nashi (lace-bug), diamond spodoptera (Earias pudicana pupilana Stamdinger), mites, leaf roller moths, grass borers, and so on.

1. The focus is on the prevention and control of Stephanitis nashi: also known as Pear lace-bug, which is distributed all over the country and harms azaleas, cherry blossoms, peach trees, plums, and other plants.

Damage symptoms: imago and larvae cluster on the underside of leaves and suck sap, resulting in splashed black sticky substances on the underside of leaves. This feature is easy to distinguish from other piercing and sucking pests. The back of the entire affected leaf is rusty yellow, and many pale spots are formed on the front. When the damage is serious, the spots form into pieces, and the whole leaf becomes chlorotic, and it looks pale from a distance, resulting in weak plant growth and early defoliation.

Stephanitis nashi occurs in 4-5 generations a year in the Yangtze River Basin and 3-4 generations in North China. The imago begins to lay eggs when the temperature is above 10 ℃. Generally, Rhododendrons/azaleas in various places are affected from the beginning of flowering. The first generation has a long development time due to low temperatures, so it is the most favorable time for chemical control. Use 40% omethoate, dinotefuran, and malathion, along with plus the mixed use of acetamiprid or imidacloprid will achieve the best effect, and it is also useful for controlling other pests (Generally, spray once every 10-15 days, and spray 2-3 times continuously). Remember: These 2 sprays must be used carefully and thoroughly, and other host plants around should also be controlled together to prevent cross-spreading hazards. If the first generation of control is not thorough, there will be overlapping generations after June, and various insect states often exist at the same time, making control more difficult. Therefore, it is the key to thoroughly prevent the first generation of stephanitis nashi.

【Stephanitis nashi】 

2. The damage of Earias pudicana pupillana Staudinger has been aggravated in recent years. The larvae mainly feed at night, and they eat at the growth position and inside the flower bud. The daily feeding range is very large, and the damage is rapid. In a short period of time, the azalea will lose its buds, so that the flowering in the coming year will be reduced, or even be no flowers. The best time and method for prevention and control is to regularly use lufenuron, emamectin, perfluthrin, chlorpyrifos, and other chemicals for rotation control every 20-30 days from June to September.

【Earias pudicana pupillana Staudinger】

If conditions permit, insecticidal lamps can be used for trapping to reduce the number of insect populations. The above measures are also suitable for the control of pests such as leaf-rolling moth (rolling leaves and eating leaves), grass borer, scarab beetle and so on.

3. The harm of mites (mainly broad mites) is related to the variety of azalea. Generally, the leaves with bright colour and the medium-sized leaves are susceptible to such pests. Especially in the high temperature and low rain season, the damage is more serious, causing the new leaves to roll out, and even leading to leaves shriveling and unable to unfold (previously believed to be a lobular disease caused by nutrient deficiency was wrong).

There are many pesticides for the control of mites, and it is advisable to use a combination of ovicidal and insecticides, and the pesticides should be used in rotation to slow down the resistance. In the open field, there are more natural enemies of mites, which can have a certain control effect. Secondly, azaleas varieties that are more resistant to mites do not need to be controlled.

【Symptoms of mites effects, ranging from mild to severe】

There are not many types of diseases and insect pests on azaleas. Generally, a comprehensive prevention and control measure of multiple diseases and insect pests can be carried out to improve cultivation efficiency.

【Other pests: tortricid, Fall Armyworm, Chafer larva】

Finally, in order to protect the environment and reduce environmental pollution, please choose azalea varieties with strong resistance!