Brown roundworm, also known as tea brown roundworm, belongs to the order Homoptera, shield ants. It harms more than 200 kinds of plants such as citrus, lemon, coconut, banana, fig, chestnut and tea. Can harm trunks, branches, leaves and fruits. Branch damage is manifested by rough epidermis and weakened tree potential; poor growth after young branches are damaged; chlorophyll decreases after leaf damage, and pale yellow spots appear; after fruit damage, the epidermis has uneven spots and the quality is reduced. The northernmost place in China is Shenyang, Liaoning, Baotou, Inner Mongolia, and Yinchuan, Ningxia, but it can only spend the winter in the greenhouse; it can only spend the winter in the greenhouse; it reaches Taiwan, Hainan and Guangdong, Guangxi, and Yunnan in the south, the coast in the east, and the West folds into Sichuan and Yunnan from Shaanxi, and continues to the west, collecting camphor and Jilong in Tibet. South of the Yangtze River, the density is larger.
Leaf brown roundworm
Fruit brown roundworm
Harmful symptoms
Female adults and nymphs are fixed on the leaves, fruits and young shoots to suck sap, and the macula is formed in the victim area, resulting in leaf deformity, curling, dry branches and leaves, and the fruit is yellow-green, with poor appearance and fruity taste; it seriously affects the tree posture, yield and fruit quality, and can also induce bituminous coal disease.
habit
After hatching, the nymphs crawl out of the edge of the shell and crawl on the leaf surface, fixing after several hours. This stage is called wandering nymphs after hatching and before fixation. Wandering nymphs have strong viability, and can survive for 6 to 13 days when there is no food, and the optimal temperature for activity is 26 to 28 °C. Wandering nymphs prefer to settle on leaves and ripe fruits.
Prevention and control methods
(1) Agriculture. Cultivate tree potential and improve the insect resistance of the tree itself. Before April, timely pruning of insect branches, shaded branches and dry dead branches to improve the ventilation and light transmission conditions of citrus orchards. Found that the fruit surface and branches have a jagitic tip hazard in time to remove.
(2) Pharmacy. 1. Pick and treat into tick spray 40% rapid culling emulsion 7; 40% chlorpyrifos emulsion, 25% chlorpyrifos, oxidation of Leguo, dichlorvos in the nymph stage for control
2. When severe, l chlorpyrifosate and 30% thiopheazine can be used
Severe cases occur every 15 to 20 days, 2 to 3 times in a row.
Dense brown roundworm