What should I do if my Wei Zihua is infected?

Also known as pomegranate tapestry, it has two generations in 1 and overwinters as eggs or nymphs. Female adults and nymphs suck juice on bud axils, leaves and branches, causing black branches and leaves to fall off, which seriously affects the growth and development of trees. Their excreta can induce sooty blotch, which is one of the main pests that harm Lagerstroemia indica.

Prevention and control methods:

1. Strengthen quarantine, prevent the inflow of germs, apply fertilizer rationally, enhance the insect resistance of plants, keep ventilation and light transmission, avoid excessive plant density, and combine pruning in winter and early spring to burn insect branches. When the quantity is small, it should be scraped off manually.

2. Chemical control. (1) Spray 10- 15 times of turpentine mixture or 40-50 times of engine oil emulsion 1-3 times in winter to eliminate overwintering females. (2) Before germination, spraying 3-5% sulfur mixture or 3-5% diesel oil emulsion to kill overwintering nymphs. (3) Nymphs are the key to control. First, the newly hatched nymphs unearthed should be sprayed with 500 times solution of 50% carbaryl wettable powder or 5% phoxim EC 1000 times solution on the soil surface around the roots in early spring. During the incubation period, when the shell is not thickened and the pesticide is easy to penetrate, spray it every 7 7- 10/time for 2-3 times continuously, and choose 40% omethoate emulsion, 80% dichlorvos emulsion, 50% phoxim emulsion and 25% iminophosphate emulsion 1 00.

3. The polymer film is sprayed on plants to form a film, so that insects suffocate and die, and the natural enemy Lepidoptera rubra is used for predation. In order to get good results.

Third, crape myrtle

In northern China, 5-8 generations occur every year, and eggs overwinter near buds and branches. May is the initial stage of the disease, and June is the peak. Nymphs and adults cluster to harm young leaves and suck juice, which affects growth and development.

Prevention and control methods:

1. Scrape the old bark, cut off the damaged branches in early spring, and burn them centrally to eliminate the overwintering eggs.

2. Strengthen cultivation management measures to reduce the source of disease.

3. When the amount of aphids is large, cough 40% omethoate, 40% acephate 1000- 1500 times or spray spermidine 1000-2000 times, but pay attention to avoid phytotoxicity.

4. Artificial propagation and diffusion of natural enemies, such as harmonia axyridis and grassridge larvae, where conditions permit.

5. Use colored boards to trap and kill winged aphids, or use white tin foil to reflect light and refuse to fly.