Spinosad, also known as polymyxin, is a highly efficient and environmentally friendly biological insecticide extracted from the fermentation broth of Saccharomyces spinosa, a type of macrolide. The parent strain of soil actinomycete Saccharopolysosa spinosa Metrz&Yao, which produces fungicides, was initially isolated from an abandoned brewery in the Caribbean. Researchers from Dow Agrochemical Company (now Dow Agricultural Sciences) in the United States have found that this bacterium can produce compounds with very high insecticidal activity. The practical product is a mixture of spinosyn A and spinosyn D, hence it is called spinosad. The mechanism of action of polymyxin is novel, as it can continuously activate target insect acetylcholine nicotinic receptors, but its binding site is different from nicotine and imidacloprid. Doxycycline can also affect GABA receptors, but the mechanism of action is unclear. It is currently unknown whether there is cross resistance with other types of insecticides. These compounds can cause rapid death of target herbivorous insects such as caterpillars, leafhoppers, thrips, and leaf eating beetles, despite strong regulatory requirements for use when resistance has not yet emerged. The moderate residual activity of these compounds reduces the likelihood of resistance and colony formation. When applied at 12-150g/hm, no drug damage was found.

ISO Common Name: spinosad

CIPAC numerical code: 636

Structural type

Spinosyn A: R1=N(CH3)2，R2=H，R3=CH3

Spinosyn D: R1=N(CH3)2，R2=CH3，R3=CH3

Experimental formula: Spinosyn A：C41H65NO10、Spinosyn D：C42H67NO10

Relative molecular mass (based on 1999 international atomic mass): Spinosyn A：731.98、Spinosyn D：746

Biological activity: insecticidal

It has a slight odor of stale soil. The vapor pressure is about 1.3 × 10-10Pa. In an aqueous solution with a pH of 7.74, metals and metal ions remain relatively stable for 28 days. The half-life of photodegradation in soil is 9-10 days; The half-life of hydrolysis is 1 day. Relatively stable in aqueous solution within the pH range of 5-7; Half life of 200 days at pH 9. Polyfungicide is a mixture containing more than ten components, with the main components being A and D. The melting point of spinosad A is 84-99.5 ℃, with a vapor pressure of 3.2 × 10-10Pa. Its solubility in water is 290mg/L (pH=5.0), 235mg/L (pH=7.0), and 16mg/L (pH=9.0), respectively; The distribution coefficients under corresponding pH conditions are 2.8, 4.0, and 5.2, respectively. The melting point of fungicide D is 161.5-170 ℃, with a vapor pressure of 2.1 × 10-10Pa. Its solubility in water is 29mg/L (pH=5.0), 0.332mg/L (pH=7.0), and 0.053mg/L (pH=90.0), respectively; The distribution coefficients under corresponding pH conditions are 3.2, 4.5, and 5.2, respectively.

Density: 1.16g/cm3, melting point: 84 ℃~99.5 ° C, boiling point: 801.5 ° C at 760 mmHg, refractive index: 1.54, flash point: 438.5 ° C, vapor pressure (20 ℃): 1.3 × 10-10Pa, solubility: water 235mg/L (pH=7); Can be miscible with alcohols, fatty hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, esters, ethers, and ketones in any proportion. Stability: Relatively stable for metals and metal ions within 28 days. Degradation occurs through various pathways in the environment, mainly photodegradation and microbial degradation, ultimately resulting in natural components such as carbon, hydrogen, oxygen, and nitrogen. It is easy to decompose under light, hydrolyzes quickly, and has a half-life of 1 day in water; Half life in soil is 9-10 days.

Other names: Cai Xi, Cui Sha

Functional characteristics

Its mechanism of action is believed to be the effector of nicotinic acetylcholine receptors, which can continuously activate target insect acetylcholine nicotinic receptors, but its binding site is different from nicotine and imidacloprid. Polybactericides can also affect GABA receptors, but the mechanism of action is unclear. It can quickly paralyze and paralyze pests, ultimately leading to death. Its insecticidal speed is comparable to that of chemical pesticides. Highly safe and non interactive with commonly used insecticides, it is a low toxicity, efficient, and low residue biological insecticide that has both high insecticidal performance and safety characteristics for beneficial insects and mammals. It is most suitable for the production and application of pollution-free vegetables and fruits. It is a low toxicity, high efficiency, and broad-spectrum insecticide.

Toxicity:

The acute oral LD50 of the active ingredient in female rats is greater than 5000 mg/kg, in males it is 3738 mg/kg, in mice it is greater than 5000 mg/kg, and in rabbits it is acute transdermal LD50 greater than 5000 mg/kg. No irritation to the skin, slight irritation to the eyes, can disappear within 2 days. Polybactericides are biodegradable in the environment, have no enrichment effect, and do not pollute the environment.

Mechanism of action

It has a rapid contact killing and stomach poisoning effect on pests, strong penetration effect on leaves, can kill pests under the epidermis, has a long residual period, and has a certain egg killing effect on some pests. No internal suction effect. It can effectively prevent and control pests of Lepidoptera, Diptera, and Thysanoptera, as well as some leaf feeding pest species in Coleoptera and Orthoptera. Its control effect on piercing sucking pests and mites is relatively poor. It is relatively safe for predatory natural enemies of insects, but due to its unique insecticidal mechanism, there have been no reports of interactive resistance with other insecticides. Safe and harmless to plants. Suitable for use on vegetables, fruit trees, horticulture, and crops. The insecticidal effect is less affected by rain.

Using technology

Doxorubicin is mainly used to control pests through spray, and when trapping and killing small fruit flies, it is used to spray bait at the spot.

(1) Spray on cruciferous vegetables, solanaceous vegetables, melon vegetables and cotton: when used, 30-45L spray water with ointment containing 2-2.5g Active ingredient every 667m2; When spraying on fruit trees, generally use 480g/L suspension 12000~15000 times of liquid, or 25g/L suspension 800~1000 times of liquid spray should be uniform and thoughtful, and the best effect is in the early stage of pests. When controlling thrips, it is necessary to focus on spraying young tissues such as tender shoots, flowers, and young fruits.

(2) When using point spray bait to control citrus fruit flies, the method of point spray bait is often used to lure and kill the fruit flies. Generally, 10 to 100 milliliters of 0.02% bait are sprayed every 667 square meters. [3]

Analysis method

High performance liquid chromatography quantitative analysis method Using methanol+acetonitrile+water as the mobile phase, C18 and UV detector for determination.

Preparation: 2.5%, 48% suspension agent, and products that are compounded with BT and some chemical pesticides.

Usage:

1. For vegetable pest control of diamondback moth, use 2.5% suspending agent 1000-1500 times of solution to evenly spray in the peak stage of young larvae, or use 2.5% suspending agent 33-50ml to 20-50kg of water spray every 667m2.

2. To control beet armyworm, water spray with 2.5% suspension agent 50-100ml every 667 square meters at the early larval stage, and the best effect is in the evening.

3. To prevent and control thrips, every 667 square meters, use 2.5% suspending agent 33-50ml to spray water, or use 2.5% suspending agent 1000-1500 times of liquid to evenly spray, focusing on young tissues such as flowers, young fruits, tips and shoots.

Precautions

1. May be toxic to fish or other aquatic organisms, and pollution of water sources and ponds should be avoided.

2. Store the medicine in a cool and dry place.

The last application is 7 days after harvest. Avoid rain within 24 hours after spraying.

4. Personal safety precautions should be taken. If it splashes into the eyes, immediately rinse with plenty of water. If in contact with skin or clothing, rinse with plenty of water or soapy water. If ingested by mistake, do not induce vomiting on your own. Do not administer anything or induce vomiting to patients who are unconscious or experiencing spasms. The patient should be immediately taken to the hospital for treatment.