Pests and control methods of rhododendron

1. Red spider

The red spider of rhododendron mainly occurs on the back of the leaf, and when the occurrence quantity is relatively large, the back and tender shoots of the leaf are also distributed. After the occurrence of the red spider, its leaves will appear small yellow and green scattered spots.

Prevention and control methods: create a well-ventilated environment to make cuckoos grow healthily and increase resistance to red spiders. If the occurrence quantity is relatively large, the important areas can be cut off to reduce the amount of mouth formation; if the branches are more and more dense, you can spray pesticides from nicotine biological sources such as avermectin.

2. Azalea net bug

Rhododendron bugs mainly occur on the back of the leaves, when they occur, they will see some black spots on the back of the leaves and small insects with transparent wings about 2-3 mm in length, and yellow and green spots on the front of the leaves, but they are smaller than the spots that occur when red spiders occur. When it occurs, it spreads from the leaf vein to the leaf edge, and the occurrence degree of the leaf center is obviously more than that of the leaf margin.

Control methods: if there are few pests, diseased leaves can be removed and burned to prevent re-infection. If the number is relatively large, imidacloprid can be used to prevent.

3. Aphids

Aphids mainly occur on the back and tender shoots of leaves, and there are some small green and white insects, some with wings and no wings, usually clustered together.

Prevention and treatment: when a small amount occurs, you can take it under the faucet and wash it off; or hang some yellow armyworm boards around the azaleas; you can also control it by soaking tobacco water. If the occurrence is relatively large, imidacloprid can be used for spraying. A second dose should be given 3-7 days after the first dose to kill the larvae that do not hatch in the eggs.