The main pests and diseases of Gannan navel orange are the following nine
1. Citrus wood lice
Harm: Wood lice suck navel orange shoots, young shoots, young leaves, causing young shoots, young shoots yellow flowers, shrinking and drying, young leaves deformed and fall off.
Prevention and control measures: do a good job in the prevention and control of wood lice in the spring, summer and autumn shoots; Use psyllids, natural enemies ladybugs, aphid-eating flies, jumping wasps and praying mantises to eliminate pyllids; Do a good job of clearing the garden in winter, reduce the number of overwintering adults, and reduce the insect population base.
2. Red Spider
Harm: Mainly harmful to navel orange leaves, young branches and fruits, in severe cases, it will cause fruit trees to fall leaves and fruits, affecting tree potential and yield.
Control measures: reduce the insect population base before the peak; Use the natural enemies of red spiders, six-point thrips, predator mites, etc., to eliminate red spiders; Red spiders have strong resistance to drugs, so when using drugs for control, pay attention to rotating medications to avoid resistance.
3. Rust ticks
Harm: Mainly harmful to the fruit and leaf back of citrus, in severe cases, it will cause the leaves to fall off, and the fruit epidermis will become rough, affecting the quality of the fruit.
Prevention and control measures: in the early stage of the peak of rust tick damage in May and July, timely spray prevention and control, spray prevention and control should pay special attention to spraying the lower part of the canopy, the back of the leaf surface, and the shady side of the fruit; Timely irrigation during high temperature and drought in the middle of summer can control the occurrence of rust ticks.
4. Whiteflies
Harm: The whiteflies that harm Gannan navel orange are mainly citrus whitefly and black whitefly, which will gather on the back of young leaves to suck sap, and in severe cases, it will cause leaf deformities and fallen leaves, causing dead shoots.
Control measures: Do a good job in the prevention and control of the first half of the year, focusing on the prevention and control of adult overwintering generations and nymphs of each generation.
5. Flower bud maggots
In the early bud stage and the early stage of falling flowers, 20% of the Chinese and Western permethrin 3000-4000 times liquid is sprayed to the ground, and the physical prevention and control is taken from the end of February to the beginning of March every year, and the shallow soil layer near the canopy is shallow tillage, which is conducive to reducing insect infestation.
6. Mesosomes
Generally, in mid-to-late December, a comprehensive spray (mainly stone sulfur compound) is used for prevention and control. Do not spray citrus trees when they have not yet regained their physiological balance after fruit picking, otherwise it will lead to a large number of leaves falling, affecting the tree potential and next year's yield. In mid-to-late February, before the spring buds are about to germinate, the citrus orchard where the mesophyllum recurs can be fully sprayed with a sodium rosinate compound, which can form a protective film on the trunk and leaf surface, and close the mesophyllum to death
7. Aphids
Aphids are the accomplices of citrus disease Citrus recession disease is a disease caused by citrus stem pitting virus, diseased trees generally appear dwarfed, leaf distortion and fruit smaller and other pathologies, linear virus is the pathogen of citrus recession disease, the transmission route is through the poisonous seedlings and poisonous buds, skin and leaf fragments grafted infection, in the field mainly through orange aphids, cotton aphids, orange dipteros, meadowsweets and other aphids spread. Among them, the orange aphid has the strongest pathogenicity. Aphid control points 1, timely wipe control of the shoots Due to the tenderness of aphids, the irregular growth of young shoots will be erased. When pruning in winter, the affected branches and aphid branches can be pruned, combined with the winter garden scraping to kill the overwintering insect eggs on the branches. 2. Adopt orchard grass cultivation to cultivate natural enemies control and stick-catching ladybirds, grassfly, aphid-eating flies, parasitic bees and parasitic bacteria are all very effective natural enemies for ecological prevention and control. As far as possible in citrus groves, a provocative approach is used to protect and exploit predators. At the same time, yellow armyworm plates can also be set up in orange groves to trap a large number of winged aphids. 3. Chemical agent control scheme When there are 20% aphids in the new shoots, 10% imidacloprid wettable powder 2500-3000 times liquid can be selected
8. Butterflies
Hazards: Eating out leaves
Artificial prevention: direct hunting when a small amount, booby-trapping with vinegar in large quantities, or releasing natural enemies to eliminate. Hazard characteristics: In the case of many larvae, the leaves will be eaten, including old leaves. Shape characteristics: Usually green, lurking on the leaves is difficult to spot.
(1) A small number of bugs can be found to catch and kill, and the effect is more obvious and direct.
(2) When a large number of insect pests occur, booby traps with sweet and sour liquid can also release natural enemies to eliminate insects, and parasitic wasps can be used to control and control, and it is best to eliminate them during the spawning period
Biological control: Bacterial pesticide preparations can also be used, such as one acre sprayed with Bacillus thuringiensis wettable powder 150 agents.
9. Weevil
Eating out the leaves and harming young fruits
Biological pesticide prevention and control: the use of high-efficiency and low-toxicity permethrin pesticide spray control, the effect is very good, die fast, die thoroughly, long control period, short residue period, less residue, do not pollute the environment, do not endanger human health. After 15 to 20 minutes of spraying, they fell to the ground and died.
10. Leafminer moth
Leafminer moth, one of the main leaf-eating pests on citrus, occurs to varying degrees in citrus growing areas throughout China. Leafminer moth larvae form a meandering worm path on the leaf epidermis, and the farmer's image is called a ghost marker. Curly leaves and "ghost charms" can be seen everywhere in the badly victimized orchards, making the orchards look like they have been "under a spell". August to September is the peak period of leafminer moth occurrence throughout the year, we must pay attention to prevention and control! At present, there are fewer insecticides that can penetrate the eggs, once the larvae drill into the epidermis, they can only be effective with systemic insecticides, adult insects often lie out at night, spray at night to be effective, and the first peak period begins to occur when the temperature and humidity are suitable from late April to early May, and the first peak period occurs; the second peak period is the second peak period in early june; the second summer shoot is mainly harmful in July, and there is a low peak period before and after autumn; late August to early September is the peak period of the whole year, and the number of insects is large and rampant.
防治重点技术：
Control zero chaos and promote unified release. When the young shoots grow to 1 to 2 cm, the whole plant is erased with sporadic new hair, about once every 5 days, and several times in a row, to promote the neat withdrawal of the shoots;
Grasp the occurrence rules, choose to release the shoots uniformly at the low peak of the adult insects;
Seize the critical period to spray the paralysis. When a large number of autumn shoots germinate and young shoots grow to about 1 cm, they should be sprayed immediately for protection, sprayed at night to control adult insects, and sprayed against larvae in the afternoon on sunny days;
Pay attention to the coverage time of the agent, timely replenishment, spray every 5 to 7 days, spray 2 to 3 times in a row, to avoid the occurrence of gaps and be endangered;
the use of pesticides with compound systemic drugs during the peak period, or the use of dosage forms with a long duration of validity;
推荐的药剂：氯氟·噻虫嗪2000倍（特效）、+菊脂类2000倍+10%吡丙·吡虫啉1500倍！
Sun Yongsong, Technical Director of Golden Autumn Agriculture and Forestry