Common pest species and control measures for rhododendrons
1 Net bug
1.1 Hazards and Symptoms. Reticulum bugs, also known as military insects, mainly parasitize the back of the leaves, and there are small brown spots on the parasitic leaves, which are most serious in July and August of each year, and the most serious will cause the leaves to fall early.
1.2 Preventive and curative measures. Deep soil in winter to clean up weeds to minimize the survival rate of pests and diseases. When the density of green belts or flower diameters is too large, properly pull out some seedlings to optimize the ventilation effect. May of each year is the frequent occurrence of this pest, at this time, with 20% of the cypermethrin 1500 times the solution for spraying, pay special attention to spraying, the back of the leaf and the side of the grass sprayed fully, every 7 to 10 days spray once, 3 times continuously.
2 Nocturnal moth
2.1 Main Hazards and Symptoms. The rose-spotted nocturnal moth is also one of the common pests that harm rhododendron buds, and the larvae of this pest eat flower buds and young shoots, which will make the young shoots die and fall, and the buds will fall hollow, affecting the growth and appearance of the rhododendron.
2.2 Preventive and therapeutic measures. When the harm is not serious, only the victim buds and young shoots need to be removed and burned in a concentrated manner; when the harm is more serious, spray with 45% of the rapid insect extermination 1000 times liquid.