What is the difference between Thuringiensis and karyotype polyhedravirus? Xiaobian sorted it out here, you can learn more about it.
Bacillus thuringiensis
Bacillus thuringiensis, or Bt for short, is a class of crystal-producing Bacillus that includes many variants. The bacteria produce two main types of toxins, endotoxins (with cytocrystals) and exotoxins, which cause pests to stop feeding and eventually the pests die of starvation and poisoning. Therefore, the bacillus can be used as a low-toxicity insecticide of microbial origin for the control of a variety of pests of Orthoptera, Coleoptera, Diptera, Hymenoptera, especially Lepidoptera.
Insect repellent principle
Bacillus thuringiensis (Bt) is a crystal-producing Bacillus that includes many variants of Bacillus, which can be used as a low-toxic insecticide of microbial origin, mainly gastric toxicity. The bacteria can produce two major toxins, namely endotoxins (with cytocytotals) and exotoxins, so that the pest stops feeding, and finally the pests die of starvation and death, while the exotoxin acts slowly and plays a significant role in molting and metamorphosis, these two periods are the peak of RNA synthesis, and the exotoxin can inhibit DNA-dependent RNA polymerase. The drug is slow, the pest can be effective about 2 days after feeding, and the effective period is about 1 day, so it should be used 2 to 3 days earlier than conventional chemicals, and the effect is better at the young age of the pest. It is safe for fish and bees, but highly toxic to silkworms.
Its main active ingredient is one or more insecticidal crystal proteins (ICPs), also known as δ-endotoxins, for lepidoptera, Coleoptera, Diptera, Hymenoptera, Hymenoptera and other insects, as well as animal and plant nematodes, ticks and other arthropods have specific toxicic activity, and for non-target biosecurity Therefore, Bt insecticides have the advantages of specificity, high efficiency and safety for people and animals, etc. At present, the commercial preparation of Subhallus thuringiensis has reached more than 100 kinds. It is the most widely used, the largest and the best effect of microbial insecticides in the world, so it has attracted much attention. However, commodity Bt preparations also show certain limitations in the production and control, such as poor quick availability, insensitivity to elderly larvae, short shelf life in the field, and unstable genetic traits of recombinant engineered strains, which have become constraints on the further successful promotion and use of Bt. Therefore, in order to improve the insecticidal effect of Bt preparations, the study of their synergistic pathways has become a worldwide research hotspot, mainly including: screening synergistic strains; The use of chemical additives, plant senseins, chitinase as synergistic substances; Interaction between insect pathogenic microorganisms, etc.
Fields of application
Thuringiensis is used in a wide range of crops. Widely used in cruciferous vegetables, nightshade vegetables, melon vegetables, tobacco, rice, sorghum, soybeans, peanuts, sweet potatoes, cotton, tea trees, apples, pears, peaches, dates, citrus, thorns and other plants; It is mainly used for the control of lepidoptera pests, such as cabbage insects, small cabbage moths, beet nocturnal moths, twill nocturnal moths, kale nocturnal moths, smoke green insects, corn borers, rice longitudinal leaf borers, dimorphic borers, pine caterpillars, tea caterpillars, tea inchworms, corn armyworms, bean pod borers, silver-striped nocturnal moths and other pests. Some subspecies or strains also have a control effect on pests such as vegetable root-knot nematodes, mosquito larvae, and leek maggots.
Karyotype polyhedravirus
Nuclear polyhedrosis viruses, a class of obligate insect viruses whose processing agents are viral insecticides.
Karyotype polyhedra viruses are dodecahedral, tetrahedral, pentagonal, hexagonal, etc., with a diameter of 0.5-15uM, embedded in multiple virions, composed of proteins, insoluble in water, ethanol, ether, chloroform, benzene, acetone, 1mol/l hydrochloric acid, soluble in sodium hydroxide, potassium hydroxide, ammonia and sulfuric acid aqueous solution and acetic acid. Mostly develops in the nucleus of the host's blood, fat, chlorine tube, skin limb and other cells, so it is called karyotype polyhedravirus. Karyotype polyxel viruses host a wide range, mainly parasitic lepidoptera. Infection through oral or wound. The virus that enters the worm body through the mouth is digested by gastric juice, free of the baculus virus particles, through the midgut epithelial cells into the body cavity, invades the cell, proliferates in the nucleus, and then invades the healthy cell until the insect is dead. Diseased feces and dead insects re-infect other insects, causing viral diseases to circulate in pest populations, thereby controlling pest hazards. Viruses can also be transmitted to insect offspring through eggs. Specialized, a virus can only parasitize one insect or its neighboring population. It can only proliferate within living host cells. Relatively stable, in the natural conditions without direct sunlight can be stored for several years without inactivation. The nucleotype polyhedra virus of the powdered nocturnal moth can maintain infectivity in soil for about 5 years. No pests have been seen to develop resistance. Safe for humans and animals, birds, beneficial insects, fish, etc. Not resistant to high temperatures. It is easily killed by ultraviolet rays, and the sunlight exposure will be inactivated. Can be killed by disinfectants.
It is mainly used for the control of agricultural and forestry pests. Cotton bollworm karyotype polyhedral virus has been used in about 20 countries to control cotton, sorghum, maize, tobacco, tomatoes bollworm. The world's most successful large-scale applications are also pine yellow leaf bee, pine leaf bee, Viconia pine leaf bee, dancing poison moth, poison moth, canopy caterpillar, alfalfa powder butterfly, pink nocturnal moth, solid nocturnal moth, twill moth, acacia tree moth and other pests of the kary polyhedral virus. China's own isolation and cultivation, large-scale field treatment of insects to achieve good results are cotton bollworm, mulberry caterpillar, twill nocturnal moth, dancing poison moth nuclear polyhedral virus.
Through the above insect control principles and application areas, we have a more comprehensive understanding of Thuringiensis and karyotype polyhedravirus.
Yunzhongdi service purpose: an attitude, focus on rice and wheat planting technology of agricultural self-media, to help farmers popularize planting technology knowledge, to solve farmers planting problems. If there are any deficiencies, I hope my friends will comment. For more details, please adjust slightly according to the local climate, soil conditions, or consult the local agricultural department.