Rhododendron pests and control methods

1. Red spider

The red spider mites of azalea mainly occur on the back of the leaves. When the occurrence is relatively large, they are also distributed on the back of the leaves and young shoots. After red spider mites occur, small scattered yellow and green spots will appear on its leaves.

Prevention and control methods: Create a well-ventilated environment to allow azalea to grow healthily and increase resistance to red spider mites. If the occurrence is relatively large, you can cut off the important areas where the disease occurs to reduce the number of bites; if the branches where the disease occurs are numerous and dense, you can spray them with nicotine-based biogenic insecticides such as avermectin.

2. Cuckoo web bug

The cuckoo web bug mainly occurs on the back of the leaves. When it occurs, some black spots and small insects with transparent wings about 2-3 mm long can be seen on the back of the leaves. Yellow and green spots will also appear on the front of the leaves, but they are smaller than the spots that appear when red spider mites occur. When it occurs, it spreads from the veins to the leaf edges, and the incidence in the center of the leaf is significantly greater than that at the leaf edges.

Prevention and control methods: If there are relatively few pests, the diseased leaves can be removed and burned to prevent reinfection. If the occurrence is relatively large, imidacloprid can be used for prevention.

3. Aphids

Aphids mainly occur on the back of leaves and tender tips. Some small green and white insects will appear, some with wings and some without wings, and they usually gather together.

Prevention and control methods: When a small amount occurs, you can flush it under the tap; or hang some yellow sticky insect boards around the azalea; you can also use tobacco water to prevent and control it. If the occurrence is large, you can use imidacloprid for spraying. A second application of the medicine should be done 3-7 days after the first application to kill the unhatched larvae in the eggs.