Have you ever noticed that there is wood slag under the tree? Branches are drilled, easily broken, or even riddled with holes? This is the encounter with the heart worm, the scientific name is Tianniu.
Tianniu is a pest of the Coleoptera family, mainly harmful to apples, grapes, pear trees, cherries, peach trees, citrus, walnuts and other fruit trees, poplars, willows, pines, elms and cotton, wheat, corn and other forest trees and crops on the main pests, the harm is very serious, widely distributed in China's Guangdong, Guangxi, Jiangxi, Hunan, Hubei, Henan, Hebei, Shandong, Shanxi, Tianjin, Inner Mongolia and other parts of the country.
Harmful symptoms
Tianniu mainly uses larvae to drill the branches of the tree fruit trees of the moth forest, the adult insects will lay eggs in the gaps of the young buds, after the eggs hatch, the hatching larvae enter the cortex from the young buds, first harm under the cortex, and then gradually enter the xylem hazard, and leave a large amount of insect feces in the worm road, part of the insect feces will flow out of the worm road, affecting the growth and development of the tree, making the tree weak, resulting in the invasion of pathogens, and it is easy to be broken by the wind. When the damage is severe, the whole plant dies, the wood is mothed, and it loses its use value.
Regularity of occurrence
Tianniu mainly uses larvae to overwinter in the branches of various trees, the following spring, when the climatic conditions are suitable, generally in late April, the larvae begin to move, and drill the branches of the moth, in early July the larvae mature, and pupate in the vents in the wormhole, feathered into adults in August, adults eat young stems, shoots and leaves, after 10 days the adults mated to lay eggs, the eggs were laid in the gaps of the young buds, the eggs were scattered, each laying 1 egg, the egg period was about 5 days, after the eggs hatched, that is, they entered the cortex through the young shoots, and then entered the xylem hazard. In October, when the outside temperature is low, the larvae enter the overwintering.
The main breed of Tianniu
There are many types of Tianniu, common ones are Xingtian Niu, Mulberry Tianniu, Bare shoulder Star Tianniu, Peach Red Neck Tianniu, White Rib Tianniu, Red Edge Tianniu, Cloud Spot White Strip Tianniu, Bamboo Edge Tiger Tianniu, Deep Mountain Tianniu and so on.
Hazard object
There are many kinds of celestial cattle, and many types of fruit trees that harm forests and crops include apples, pears, apricots, peaches, grapes, citrus, walnuts, mangoes, lychees, longans, pomegranates, etc.
The main trees in the forest are willow trees, elms, pine trees, cypress trees, locust trees, mulberry trees, poplar trees, tea trees and so on
The main crops are wheat, corn, cotton, sorghum, sugarcane and so on.
Prevention and control methods
(1) Poisoning larvae: In May to June, it is the peak of the harm of Tianniu larvae, which can be diluted with 48% chlorpyrifos emulsion 5 times the liquid of the drug and put into the bottle for backup, and when the ventilation hole of the Tianniu larvae is found, the cotton ball can be stuffed tightly with forceps. When excrement and wood chips cannot be discharged, the larvae of the celestial cow will use their mouths to bite the cotton ball to clean the passage, and they will be poisoned as soon as they bite. This method is convenient to operate, the insecticidal effect is good, and the effect period is long.
(2) Spray control: In the peak period of adult feathering of Tianniu, 900-1300 times of liquid can be diluted with 2% thiamethoxoline microcapsulant suspension, and the forest spray can be carried out with a motorized sprayer. After 2 hours of application, Tianniu began to die in large numbers, and the prevention and control effect after 24 hours could reach more than 90%. The duration of validity can reach 40 to 90 days. The number of applications and dosages have been greatly reduced, so that pests at different stages can be controlled, and the cost of control has been greatly reduced.
Source: Suiyang Agricultural Science