Every year, 5-8 generations will occur in the north, overwintering with eggs. The early stage of the disease is in May and into June. Aphids can suck juice, harm young leaves, and threaten the growth of Lagerstroemia.
In early spring, the old bark of crape myrtle trees should be scraped off, and the damaged branches should be cut off and burned intensively to eliminate the eggs of overwintering insects as much as possible. At ordinary times, we should strengthen cultivation management to reduce the source of disease.
When the aphid is serious, it can be eliminated by spraying 1000-2000 times solution of yutengjing or 40% Omethoate and 40% acephate 1000-1500 times solution, but at the same time, pay attention to avoid drug damage. If conditions permit, measures of artificial propagation and releasing natural enemies can also be taken. It is a good choice to raise Ladybug or grass ridge larva. In addition, we can also use color board to trap and kill aphids with wings, or use white tin paper to reflect light and refuse to live and move.
Two generations occur every year, overwintering with eggs or nymphs. Female adults and nymphs often suck juice on bud axils, leaves and branches of Lagerstroemia indica, which leads to blackening of branches and leaves and shedding of leaves, which is not conducive to the growth of Lagerstroemia indica. In addition, the excreta of the pest can also induce coal pollution, with a high potential risk.
In winter and early spring, prune the branches, burn the insect branches intensively, try to eliminate the eggs, and scrape the pests found manually. Strengthen management and quarantine, and apply fertilizer reasonably to enhance the insect resistance of plants, avoid excessive plant density, maintain the ventilation of plants, and do a good job in light transmission. The polymer film can be sprayed and sprayed evenly, which will form a thin film on the surface of the plant. It will cause the breathing difficulty of the worm and suffocate. If necessary, chemical control can be taken.
