How to control underground pests of medicinal plants?

How to control underground pests of medicinal plants?

1 Agricultural control

1) Plough the land deeply and cultivate intensively. Deep ploughing and soil ploughing is mainly to change the living environment of underground pests through deep ploughing, so that the pests in deep soil are exposed to the surface, threatened by high temperature, low temperature and drought, causing their death, or being preyed by natural enemies, reducing the density of insect populations; intensive cultivation has a strong mechanical killing effect on underground pests, directly leading to the death of pests.

2) Clean the countryside. Weeds are the main place for underground pests to hide or lay eggs, and the weeds in the field should be removed in time after harvesting to reduce the number of overwintering larvae and pupae. During the growth of medicinal plants, the weeds in and around the field should be removed in time to reduce the intermediate host of pests and destroy their spawning sites.

3) Reasonable rotation or intercropping. The former stubble is a plot of beans, peanuts, sweet potatoes and corn, which is often severely affected by grubs, which is associated with the feeding and spawning activities of adult grubs (scarab beetles). Therefore, the cultivation of medicinal plants should avoid such plots or rotate and intercropping with non-grass crops as much as possible, reduce pest feeding, and naturally control pest density.

4) Timely irrigation to kill insects. Soil moisture can control the activity of underground pests, in plots with better water sources, underground pests can be controlled by irrigation without affecting the normal growth of Chinese herbal medicines. Ground tigers, caddisflies, crickets, etc. can be killed by irrigation, while grubs and so on will migrate deep into the soil layer and stop harming.

5) Scientific fertilization. Farm manure piled up with crop straw and livestock manure is easy to attract underground pests to spawn, so do not apply uncorried farm manure to avoid being brought in a large number of eggs and attracting adults to lay eggs, causing pest outbreaks. In addition, chemical fertilizers such as ammonium bicarbonate can produce ammonia gas, which should be applied deeply to the soil, which can not only improve fertilizer efficiency, but also kill or avoid underground pests through corrosion and fumigation.

2 Physical control

1) Lights booby trap adults. Adult insects such as grubs, ground tigers, caddisflies and some golden needle worms have a strong tendency towards black light, and can use black light lamps to trap adult small ground tigers in March and April, and use black light lamps to trap scarabs and caddies in May and June. Gao Yan research found that the use of 4 591. The frequency vibration insecticidal lamp with 93lx brightness has a good luring effect on underground pests such as scarab beetles, caddisflies, crickets and so on.

2) Manual capture. In the seedling stage of medicinal plants, every morning in the field, the soil surface around the infested seedlings is opened, and the underground pests are caught and intensively treated.

3 Chemical control

The principle of chemical prevention and control is to prescribe the right medicine, timely use of drugs, rational use of drugs, and scientific application of medicines, including the use of soil treatment, medicinal seeds, root irrigation, sprinkling of poisonous soil, poisonous bait booby traps, plant spraying, and smearing of stems. In addition, because Chinese herbal medicine is closely related to people's health, the principle to be followed is to use high-efficiency, low-toxicity, low-residue pesticides (such as octylthion, dimethoate, permethrin pesticides, etc.) or dosage forms (such as microcapsule suspensions), and it is forbidden to use highly toxic and high-residue pesticides to control underground pests of Chinese herbal medicines.

In addition, the use of chemical ecology to control underground pests is also an important pollution-free control method. Such as the use of pheromones, aggregate pheromones, host volatiles and other chemical information substances, luring and killing underground pest adults, in order to reduce the number of insect populations to reduce larval pests as pests, is a specific, environmentally friendly pest control means. At present, many of the scarab pheromones of the gill and golden turtle families have been identified. Li Xiao et al. used sexual attractants to control the dark gill golden turtle in the peanut field, and the larval decline rate reached 78. ８％。 Luo Zongxiu et al. discussed the field application of the dark gill golden turtle pheromone, and clarified the influence of the proportion, dose, solvent and core type of information compound and the type and height of the trap on the amount of trap. Studies on the prevention and control of small-ground tigers by sexual attractants have shown that the rate of insect population decline can reach more than 60% after two consecutive entrapments. In terms of plant-derived attractants, Li Weizheng et al. studied the different formulations and field effects of castor source attractants, and obtained a formula that has a good luring effect on the North China Great Black Gill Golden Turtle, the Dark Gill Golden Turtle, the Patina Golden Turtle and the Melassofen Golden Turtle.

4 Biological control

1) Pesticides of plant origin. Some plant-derived active substances have the effect of killing and avoiding underground pests, and have the advantages of easy decomposition, no pollution to the environment and relative safety for non-target organisms. Some plant leaves are soaked in water and the stem or root bark is ground into powder, which has a good control effect on underground pests. For example, the ginkgo fruit coating processing liquid has a good control effect on grubs and caddisflies, castor leaf water immersion spraying or cypress leaf powder seed mixing can kill grubs, mujing leaf water immersion liquid can kill tigers, and some plant scraps such as oil tung seed cake and tea seed cake are both high-quality organic fertilizers and have the effect of controlling grubs and improving soil.

2) Insect pathogenic microorganisms. Including insect pathogenic bacteria such as Bacillus thuringiensis (Bt), insect pathogenic fungi such as green zombie, white zombie and insect pathogen nematodes such as Stenis nematode, Xeno-small rod nematode, etc., with a wide range of hosts, strong lethality and high safety characteristics. In particular, insect pathogen nematodes have the ability to actively search for hosts, which has a special control effect for underground pests that are difficult to control and concealed, and has a wide range of application prospects. A number of strains of Thuringiensis strains that are toxic to grubs have been screened out, white zombie and green zombie bacteria have been initially applied in the field in grub control, and insect pathogen nematodes have also achieved good control results in the control of grubs and ground tigers.

3) Predator insects. Parasitic wasps are important natural enemies of underground pest larvae, such as the gluteal hooked earth bee is the main natural enemy of the large black gill golden turtle, the dark gill golden turtle, the hairy yellow gill golden turtle and the apple-haired golden turtle of the golden turtle family, and the arc liden turtle hook earth bee is the main natural enemy of the Japanese arc golden turtle, and can also be used to control the aquatina golden turtle. Wang Weiguo et al. conducted a systematic study on the biological learning of the arc li golden turtle hook earth bee, and used it to control the large black gill golden turtle in the peanut field, and achieved good control effect.