The red spider of Rhododendron mainly occurs on the back of the leaves. When the amount of occurrence is large, the back and young shoots of the leaves are also distributed. After the occurrence of red spider, its leaves will appear small yellow and green scattered spots.
Control method: create a well ventilated environment, make Rhododendron grow healthily and increase resistance to spider. If the amount of occurrence is relatively large, the important area can be cut off to reduce its mouth amount; if the branches are more dense, they can be sprayed with insecticides of nicotine biological sources such as abamectin.
Rhododendron webbug mainly occurs on the back of the leaves. When it happens, it will see some black spots on the back of the leaves and small insects with transparent wings about 2-3 mm long. There will also be yellow and green spots on the front of the leaves, but the spots are smaller than those when red spider occurs. When it occurs, it spreads from the vein to the edge of the leaf, and the degree of occurrence of the center of the leaf is obviously more than that of the edge.
Control method: if there are fewer pests, the diseased leaves can be removed and burned to prevent re infection. If the incidence is large, imidacloprid can be used to prevent
Aphids mainly occur in the back of the leaves and the tender tip, some green and white insects will appear, some have wings and some have no wings, usually clustered together.
Control methods: when a small amount of it occurs, you can take it to the tap and wash it off; or hang some yellow armyworm boards around the Rhododendron; or you can control it by soaking tobacco water. If the occurrence is large, imidacloprid can be used for spraying. After using the first medicine for 3-7 days, we need to use the second medicine to kill the larvae that are not hatched in the eggs.
